HDRI News

Siggraph Part 3: Tonemapping Papers

2008-08-26T23:35:00.000-07:00

When you want to see what's really happening on the frontier of imaging technology, you'd have to watch some technical paper sessions. The smartest people from universities all over the world present their latest research, and you get a glimpse of what's coming - way before it's incorporated into a product.

It's actually quite funny how HDR images are often used as test material for all kinds of new imaging algorithms, as if HDRI would already be the standard. That's how far these guys are ahead. However, I would like to highlight some new tonemapping approaches. Developers - please pay close attention, users - please refrain from drooling all over your keyboard.

Lischinski's Edge-Preserving Decompositions

The most important part in a Local TMO is the separation of different detail levels. It's usually done in a preprocess, before you can adjust any settings. This is the part where small-scale details are isolated from large-scale contrasts, and the quality of this isolation has a huge impact on the tonemapping result. If it's done poorly, you get halos.

Most programs use a bilateral filter for this extraction, which used to be the best way to preserve hard edges while smoothing global lighting changes. If you're a Photomatix user, you've seen this decomposition at work:

Example implementation of a tonemapper based on the new WLS preprocessing. Watch the movie to see this in action.

Now a project group at The Hebrew University, in collaboration with Microsoft Research, has developed a new method with significant improvements. They call it the Weighted Least Squares (WLS) Optimization, and it does a much better job at preserving edges and thus suppressing halos.

Check out this project's website for example results, the full paper, and some code. Do not miss the movie presentation!

Tonemapping Quality Evaluation

How do you judge a tonemapping result?

Isn't it purely a matter of taste? Can this be quantified at all?

Sure it can. You just have to ask the right questions. Quality evaluation is not about 'good' or 'bad' results. Instead, it tells you how much of the dynamic range got lost in the conversion, how much details you managed to extract, and where halo artifacts got introduced. And when you can clearly name a problem, you can go ahead and fix it.

Tunç Ozan Aydın from the Max-Planck-Institute presented a new algorithm, that has all the answers. It can compare an HDR image with a tonemapped LDR image and clearly maps out 3 problem areas:

Different tonemapping operators, compared via Aydın’s new image metrics.

Loss (green) - When there are details in the HDR that didn't make it into the LDR. Typically, this happens when the tonemapper compressed the range to much or clipped details.
Amplification (blue) - When the tonemapping result shows contrasts that were not just barely visible in the HDR. Sometimes a desired effect of detail enhancements, not necessarily a negative property of the result.
Reversal (red) - This identifies areas where a contrast in the LDR is the opposite from what was seen in the HDR. Should point out halos and put up warning signs of surreal appearance.

You can check out several examples in an interactive online viewer.

In a real-world application I can see such a colored overlay very useful for tonemapping previews. Kind of like the clipping warnings in Photoshop or Lightroom, that mark clipped pixels in red. The algorithms presented could also be used to create an iterative tonemapping operator, that automatically minimizes artifacts.

Why doesn’t it pick up on the horrible halo artifacts from this Fattal TMO?

It certainly has some room left for improvements. I wish it would be better in detecting halo artifacts, the arch enemies of every tonemapper. Clearly, halos are a quality measure that should be accounted for.

Read more about this on the Project's Website or evaluate your own images by uploading them to the Quality Assessment Web Interface.

Display-Adaptive Tonemapping

This is also from Max-Planck-Institute, this time in collaboration with Sharp. They call it a new tonemapping operator, but I'd call it a whole new way to think about tonemapping.

If were shopping for a new display lately, you might have noticed that contrast ratios are all over the place. They range from 1:60 for ePaper over wallet-friendly 1:10.000 LCDs, up to 1: 3 Million in high-end plasma screens. If you see a wall of 20 TVs is a store, you see 20 different images - even though they show the same channel.

The idea is now to make the tonemapping display-aware. So the all images are perceptually the same, or at least as close as the display tech can show it. And then take it to the next level, and even compensate for the ambient lighting conditions in the room.

Admittedly, this research is of limited use for us consumers right now. But it clearly shows where HDR is heading.

You can check out the paper, watch the demo movie, and if you know how to compile things you can even play with the tonemapper yourself in the latest pfstools package.

Video manipulation on a whole new level

2008-08-16T10:43:00.000-07:00

This is only border-lining our HDR topic, but it's just too awesome to go unmentioned.

Not that any of these example clips would be impossible to create today. But they require a lot of manual work from a skilled VFX artist. In fact, the "We shot it wrong - you fix it!" category is the bread and butter of the VFX industry today. It's tedious, uninspiring, and sometimes even aggravating work. Any help from a push-button automatic is welcome. Currently Mokey is the closest production-ready tool, and at EdenFX we make extensive use of it. Mixed in with After Effects, Fusion, and some 3d reconstruction in Lightwave, we get stuff done. But it's nowhere nearly as automatic as in the video shown above.

Read more on this amazing new algorithm on the project's homepage. Especially the Spacetime Fusion technique described is a required reading for ever developer making tonemapping software - could be helpful for making After Effects plugins. (hint hint nudge nudge)

Blochi

Siggraph Part 2: Everything goes Giga!

2008-08-14T19:36:00.000-07:00

xRez shows off giant Yosemite panorama

A handsome bunch:
Greg Downing (left), Eric Hanson (right) and VFX-legend Cody Harrington (middle).

One thing is for sure: Their pano is bigger than yours.

The Yosemite Extreme Panoramic Imaging Project aims at nothing less than capturing the entire Yosemite valley in one massive image. 70 volunteers, capturing 45 Gigapixel of imagery, which are projected onto super-detailed geometry scans, and then rendered into one long strip in Maya. That's crazy talk.

But the two masterminds behind xRez, Greg Downing and Eric Hanson, pulled it off, and their result is shown on in the entrance hall at Siggraph. For some reason I was expecting they would wallpaper the entire outer walls of the conference center. Actually, what you see in the picture above is only one half of it, the North Rim. Eventually you'll be able to see it on a Microsoft Surface display in the National Park's Visitor Center.

More info the xRez site, the HDView Blog, and in this insanely cool movie:

But wait - there's more...

GigaPan is catching up

Gigapano photography set for less than $500.

This is another one of these projects I was watching closely, but never got around to talk about it. The GigaPan is a robotic panohead for regular snapshot cameras, and significantly cheaper than any other robotic head around. Still, it's incredible stable and reliable, and the onboard software is a breeze to use. It was good enough for the xRez gang, so it will sure fit your needs as well.

Except, that it's still in beta. I was fortunate enough to snatch a unit (here is my puny 0.5 GPix pano), but many others were not as lucky. So the Gigapan crew is digging through a backlog of 1000+ beta applications. Well, the good news is that they have manufacturing almost sorted out, and soon to expand into a second round of beta.

More eyecandy on gigapan.org, more info on the Global Connection Project site.

AutoPano 2 splits in Pro and Giga

Alexandre Jenny, original creator of AutoPano, made a totally unexpected appearance with a booth on the main exhibition floor. Way to go, Alexandre!

He's working really hard on v2.0, to be released in December. Then Autopano will be split in 3:

AutoPano Pro - the autopano we all learned to love.
AutoPano Server - automatic server-sided stitching and website display, especially useful for real estate agents in the field.
AutoPano Giga - this is where the money is in terms of HDR-support.

Let me quickly elaborate on this:
You'll be able to stitch an HDR gigapixel panorama without shooting multiple exposures for each segment. You'd rather put your camera in auto-exposure mode, so you capture most detail you can get in a best-shot-fashion. AutoPano 2 Giga will compensate for varying exposures by assigning them the proper luminance level. So the patch you shoot in a dark ground patch will have all the detail, but in the HDR it will be much darker than the patch you shot in the sky. Actually, this is already possible with the current version of AutoPanoPro, but there are severe blending issues. Well, not anymore. The resulting Gigapixel HDR will be the perfect feed for HDView.

There is lots of other goodness across the board: GPU rendering, support for RAW and the Gigapan unit.... Check out the Feature Comparison and Upgrade Path, and if you feel experimental today you can also grab the first beta version. I know I will :)

Wow, that was a hell of a long blog post. Hope you enjoyed it, still.

Blochi

Siggraph Part 1: Superimposing DR and Mayan Temples

2008-08-13T16:21:00.000-07:00

Well, I'm still stuck in the office for the day, but that gives me a chance to write up some of my early discoveries.

Superimposing Dynamic Range

It was the first page of the first chapter of the Handbook, where I mentioned you could expand the dynamic range of a book when you could somehow print a patch that is brighter than the paper it's printed on. Well, smart students Bimber and Iwai from the Bauhaus-University Weimar & the Osaka University did just that.

So, what is it that we're looking at?

Daisuke Iwai showing off the superimposed dynamic range.

They snap a picture and project it back onto the image. May sound pointless, but it is a real eyecandy and could potentially have a huge impact on digital photolabs and in medical imaging. And it's also a little more sophisticated than I make it sound - there is realtime calibration going on (because camera and projector have different angles) and instead of a book they have an ePaper display hooked up as projection canvas.

Read their paper, or watch this movie (50 MB DivX).
Better even, visit them in their corner in Hall H.

HDR timelapse panoramas with hotspots

Right around the corner are INSIGHT, a non-profit organization for heritage archival. They made some amazing interactive tours of Mayan and Egyptian temple ruins. It's really fascinating to see these bright people use the newest high-tech to research the oldest structures man ever made.

Two things are specifically impressive about this. They have a novel Mac-based viewer application, that links panos with hotspots and a map, it can leech content from online sources, and even display panoramic timelapse videos. And you can pan in these videos. Totally awesome. The title is a bit misleading, because they do in fact show pre-tonemapped imagery. Not truly HDRI, but still awesome.

Just as awesome is their capturing device: They custom-built a robotic panohead with automatic exposure bracketing. Neato.
Check out the pano page from the Mayan Skies project, or the INSIGHT gallery.

Even better, go visit their booth and say hello! Both projects are in the back of the New Tech Showcase. Here's a map.

Siggraph Course Notes

2008-08-12T13:11:00.000-07:00

Thank you all for coming, it was a tremendous experience.

Don't forget to pick up your course notes and virtual goodie bags!

Today it's back to business as usual for me. Our client is approaching any minute and he will certainly not extend the deadline for this pilot. Which is tomorrow. Oh well, that's the price to pay for street creds: having real world visual effect shots to do. Hope to get back to Siggraph on Thursday to catch some of the newest papers at least. Computational photography looks like a really cool topic, and I've also discovered some awesome project in the back corner of the New Tech section.

I'll follow up with some reports from Siggraph in the next couple of days.
Stay tuned.

Blochi

Smart IBL on Modo / Last call for SIGGRAPH

2008-07-31T21:43:00.000-07:00

Cheer it up for Gwynne Reddick, the code warrior who wrote the latest and greatest sIBL-Loader for modo. Hurray for Gwynne!

Now modo users can enjoy the convenience of automatic HDRI-lighting setups, just by picking a preset from the familiar preset browser. At least on Windows, modo on the Mac threw up some unforeseeable problems that will still need to be resolved.

Why don't you give it a test run with the new sIBL of the month? This time it's one of my favorites, the theatre room of the one and only Man's Chinese Theatre. And if you're still craving for more sIBL-sets, I do have a special surprise announcement at SIGGRAPH up my sleeves...

Speaking of which - don't forget to sign up for the HDRI for Artists class my friend Kirt Witte has organized. Master Zap from mental images will tell you everything about HDRI in mental ray, Gary M. Davis will demo the advantages of floating-point compositing in Toxik, and Hilmar Koch will show whatever crazy cool stuff ILM has done with HDRI for Transformers. Big names, yeah. And I will speak there, too.

So mark this date: Monday, 11 August / 8.30 - 12.15 / Room 502A !

You can't miss it - it's the very first class on opening day. Essentially, we'll proudly open the Conference. See you at Siggraph.

Blochi

HDView Beta 3 with HDR support

2008-07-27T00:16:00.000-07:00

One year after the initial beta release (talked about it here), Microsoft Labs have turbocharged their new online panorama viewer. HDView can now show HDR images of massive size, re-exposed and tonemapped in realtime while you pan around with unsurpassed smoothness. The viewer is based on Microsoft's HDPhoto image format and comes with a Photoshop Export plugin that even generates the website for you.
Couldn't be more convenient.

Of course I had to test it right away. Let me present you the first

100 Megapixel HDRI on the Internet

Oh yeah, baby! Check it out!
In the upper right corner of the screen you will find a button to change the tonemapping style:

no adjustment, straight middle exposure, as if it would be 8 bit.

linear tone adjustment, equals auto-exposure in a digital camera.

non-linear tonemapping (I strongly suspect a logarithmic TMO like Photoshop's Highlight Compression).

More goodness in this new version:

fisheye mode (some like it bendy)
fully color managed (respects profiles of images and monitor)
supports placement of KML-overlays (identical to the way photos are put on Google Earth like sticky notes)
XBox and 3DConnexion controllers

See, the color management alone is a giant leap in digital imaging. You can actually pipe a photo with Adobe ProPhoto profile through HDView, and it will look right on every monitor that has a known profile. And I love the fact that the developers specifically mention support for new generations of wide-gamut, high-dynamic-range displays. When it has a profile, HDView will tonemap accordingly. Never thought I'd ever say this, but: Bravo, Microsoft! You Rock!

Read more about it on the HDView Blog. Also check out the brand new HDView HDR Gallery of my friend, co-author, and personal panorama coach Bernhard Vogl.

Essential HDR 1.0 released

2008-07-18T18:48:00.000-07:00

The program formerly known as "Project Wukong" has been released today as Essential HDR.

I've no idea why they would drop a kick-ass code name like Wukong, maybe the guys from Imaging Luminary aren't real Ninjas after all... But they are certainly nice people: You can download the demo version for free (called community version), which is essentially a demo with a bottom frame watermark and 1 megapixel size restriction. Even better, the first 1000 copies are on sale for 30% off ($48.99 instead of $69.99). Usually, it's not my style to hush-hush news out here, but I figured you might want to take advantage of this launch deal...

Quick 5-minute-review

The side-by-side comparison is a neat way to play with different tonemapping settings.

Essential HDR is an HDR generator and tonemapper. It has a global and a local tonemapping operator. The local TMO (Detail Revealer) is the big selling point. According to the developers it is a new algorithm that produces less artifacts (halos, over-saturation) and runs at a decent speed (multicore support). I can wholeheartedly agree: this is indeed a very powerful tonemapper. Without much fuzz I got a very natural images, the preview is pretty accurate, and it is super-easy to use. For control freaks there might be too few sliders, but I find it very intuitive.
The overall interface is kept simple and it blends right in with other Windows Vista applications. There is no Mac version, but it runs fine on Boot Camp or VMWare Fusion (which is what I made this screenshot on).
One thing that bugs me, is that it cannot save OpenEXR images. You're stuck with Radiance for saving your HDR image, which has less color precision. Not so cool.

Erik Reinhard comments on "Flickr HDR"

2008-07-10T07:18:00.000-07:00

Erik Reinhard can truly be called the Godfather of tonemapping. Not only did he develop some of the most successful tonemapping algorithms, he also inspired numerous software makers by writing the book that is considered the HDRI-bible: "High Dynamic Range Imaging: Acquisition, Display and Image-Based Lighting". This technically detailed book laid the groundwork for almost every HDRI software we have today. For example, Photomatix's Tone Compressor as well as Picturenaut's Photoreceptor are based on his code, Artizen and QTpfsGUI have some tonemappers named after him.

In other words, Erik Reinhard knows a great deal about tonemapping. It's his baby.

My own take on tonemapping Reinhard's example HDRI. Done by blending Photoreceptor (Picturenaut) with Details Enhancer (Photomatix) and some post adjustments in Photoshop.

And it bothers him that the three letters HDR are often associated with a certain look. There is no such thing as an "HDR look", and if you read my Handbook you should be well aware of this fact. HDRI is a tool, not a particular look (page 168 to 170). Nevertheless, surreal and impressionist images, that happen to be made from HDR images via excessive tonemapping, are calling lots of attention on flickr. I wouldn't go as far as naming these images "wrong" (although it is definitely wrong to still call them HDR). It's a matter of taste, and people without taste make tasteless images. That simple. It's always been like that, way before the advent of HDR imaging. The dangerous part comes in, when a particular tasteless use of a tool is getting so much spotlight, that it starts to become synonymous of what you can do with this tool. Dangerous, because it makes HDR look like a toy, whereas it really is a seriously powerful tool for making better quality images.

So that was my comment on Reinhard's comment on Flickr. Feel free to comment in this.

Late July update

2008-07-05T10:37:00.000-07:00

My apologies for the delay. I've been tied up last week shooting a massive amount of HDRIs on location for an upcoming pilot. Although the images are classified, I can tell you that the Sigma 4.5 is incredible! Now it takes me under 30 seconds to shoot a full blown HDRI pano, which means the director doesn't hesitate to call me into action. Pretty sweet, thank you Sigma!

What did we miss in the meantime?

Nikon D700 coming in late July

Unless you're living under a rock, you should have already read about this amazing camera. It's Nikon's answer to Canon's D5:

Full frame 12.1 MP FX sensor (same as D3)
5 fps to 8 fps (slower than D300 and D3)
51-point AF (same as D3)
Sensor cleaning (unique)
Pre-order price on Amazon: $3000

Sounds like a sweet package to me.
Read more on dpreview.com's hands-on preview or Ken Rockwell's commented preview or

Nikon's official spec sheet / brochure.

Olympus develops 360° mirror lens

Actually, this is a compact lens/camera combo, most certainly for surveillance purpose. But if the price is right and this baby runs at a decent frame rate, this might be a cool gizmo for making interactive panoramic videos.
From the example pictures on the japanese Future Creations Lab site it looks like the resolution is 1600x1200 pixels, which would be just fine for the web or capturing environments for CG lighting.
At least it's good for making headlines at Wired.com.

Site update

As regular reader of this blog you certainly expect a new Flickr Gallery and sIBL of the month. Well, you got 'em.
I have also something very special for you: a video tutorial on how to create your very own sIBL-set. I'd love to make more of these screencast videos in the future, so comments and suggestions are very welcome.

The other HDR books reviewed.

2008-06-23T00:33:00.000-07:00

Done reading the HDRI Handbook? Can't get enough of HDR? Lucky you, because there happen to be two new HDR books out, both written by photographers for photographers.

Preface

Am I right guy to write reviews for competing books? Well, I'm certainly biased, and you should keep this in mind. Proceed with caution. But I also know the subject in and out, so I can evaluate the information given in these books with confidence. After all, I see these books as complementary readings, rather than competition.

Here's a list of topics covered in neither one of them, thus exclusive to the HDRI Handbook:

32-bit image editing
manually tonemapping in Photoshop
shooting and stitching fully spherical HDR panos
lighting in 3d applications

The reference sections on file formats and HDR-capable software are much more comprehensive, and it also includes a DVD filled with example material. Yes, it might be twice as expensive, but it also has twice as many pages.

OK, now this is out of the way, and I will avoid mentioning my own book from now on. Instead, I will try to give you the most objective reviews possible. In fact, when you want to dive deeper into tonemapping, I do recommend getting one of these new books!

But which one to get?

Michael Freeman: Mastering HDR Photography

Freeman is a seasoned writer, with plenty of beautiful books on travel photography under his belt. His style is straight forward and to the point, never boring or repetitive. He can put complicated matters in simple words that actually make sense; this man is a professional with words. His photography is just as professional, he's listed in agencies all over the world.
Layout, print quality and binding are all great - 160 pages of excellence. Most topics are presented as double-page essays, that are clearly headlined. This enables quick browsing for a topic of interest, and invites for non-linear reading sessions.

The book starts with explaining the limitations of 8-bit LDR imagery, scene contrast and human perception. I love the way Freeman describes our perception of images (which is more of an acquired skill) and how he links in Gestalt theory. There are several severe implications that apply to our judgement of tonemapping results, which he responds to by creating some categories for HDR scenes to be treated differently. For example, a continuous gradient (like a foggy landscape) need a different treatment than scattered bright lights (i.e. nightshot). This chapter is a great training for your photographer's eye, and worth the admission alone.

Capturing and creating HDRIs is very comprehensively described in almost every HDR-capable software, highlighting some specific advantages of each. In boxes you'll learn about some special Photoshop tricks like stacking and pre-alignment, even manual ghostbusting techniques. I love the special case he makes for the quality gain you can get from Photosphere's unique flare removal, as well as the page on color management.

More than half of the book is dedicated to tonemapping (about 100 pages). Tool-centric mini-manuals come first, explaining the parameters of Photomatix, Photoshop, FDRTools, QTpfsGUI, and EasyHDR. Freeman then goes into problem solving mode, and elaborates on halo control and naturalness. Personally, I do share his views about overprocessing, but after all this might be a matter of taste. Freeman briefly taps into panorama stitching with Realviz Stitcher (now Autodesk Stitcher), which is in my opinion the weakest part of the book. The rest is filled with a great variety of workflow case studies. Each case study explores something new - like selectively blending multiple tonemapping results in Photoshop, using HDR for portrait shots or maximizing image quality by pre-processing the source images. When Freeman finally suggests tonemapping strategies for the HDR scene categories, as established in the first chapter, he closes this book with an elegant story arc.

Conclusion: This book is all about image quality.

Freeman uses HDRI primarily to overcome sensor limitations, his focus is on naturalness and brilliant photography in the traditional sense. I called this tonemapping style "the invisible art of true-tone mapping"; I practice it myself, and I know that it is in fact is very hard to withstand the temptation of tonemapping too hard and keep it subtle yet effective. It requires skill and a sharp eye. If you're a professional photographer, maybe in real estate or commercials, this book will teach you both.

Ferrell McCollough: Complete Guide to HDR Digital Photography

McCollough does know about naturalness as well, but he doesn't limit himself to it. For him it's all about the impact of a photograph. His book taps into all kinds of creative tonemapping techniques, exploring exaggerated looks and eye catching imagery. With many full-page prints and 5 portfolio galleries of excellent photographers from the flickr community, this book has also coffee-table qualities. The longer you browse, the more you will see you own level of acceptance shift. On first look some images might appear overdone, but on closer examination they turn into powerful pieces of art. In this way, McCollough's entire book is training tool for your creative eye.

The book starts with a brief introduction about sensor limitations and examples of scene dynamic range. I love the fact that he uses EV spans throughout the book, it makes the subject so much more approachable. A very short skid on file formats and image encoding is immediately followed by a closer look at RAW formats. He concludes, that you can get the same quality in your HDR image by shooting in JPEGs, which I absolutely agree with. Nevertheless, he does explain later on how to create HDRs from RAW files, what you can tweak in pre-processing and what you shouldn't touch. There is also some advice on using point-and-shoot cameras, so he really takes care of making HDR accessible to everyone. This entire introduction chapter is very hands-on, and stripped down to the essentials.

Tonemapping takes up the rest of the book (about 120 pages). Tools of the trade are Photomatix, FDR Tools, Dynamic Photo HDR, Artizen and Photoshop (preference given in that order). Most images throughout the book are accompanied by a box with the tonemapping settings - just simple listings, but they turn out to be an awesome reference. Where Freeman classifies types of HDR scenes, McCollough classifies the typical problems of tonemapping: Halos, noisy shadows, grainy skies. My favorite is tone reversal: when local contrast enhancements are driven so far, that regions we would normally perceive as brighter turn out darker than the rest of the image. Super-dramatic skies that appear darker than the ground are one good example, a phenomenon you see all over flickr. Tone reversal finally defines this hard-to grasp quality, that is right on the dividing line between true-tone mapping and creative expressionism.

When McCollough highlights the architectural applications, it becomes clear that he is very capable of creating a natural look. A rather interesting idea is explored in flash merging: multiple exposures are blended together, each one with the flash from different directions. Technically, this is more of an exposure blending technique than HDR, but nevertheless very cool and effective. Panoramic HDR photography is kept on a conceptual level. Instead, McCollough experiments with tonemapping single RAW images (with surprisingly great success), graduated ND filters, macro- and black-and-white photography. The book closes with some quick tips on specific subjects, like portraits, night shots and snow.

Conclusion: This book is for the creative type of photographers.

If you consider your photographic captures as mere material for creating a piece of art in digital postprocessing, you will find a lot of inspiration here. By the way - McCollough also publishes several great tutorials on HDR in his blog.

Closing thoughts: The current state of HDR photography

I can still remember pitching my first book to several publishers in 2004. The response has always been discouraging: "There is no market for this kind of fancy stuff." Today it's a different story. HDR has become big, and although I was fortunate enough to get the first consumer-level book on HDRI out, I see no reason for it to stand alone. The demand for more teaching material only underlines the point, that HDRI is now a well-established field of photography. More books on this topic can only benefit the industry as a whole. Maybe camera makers will finally listen and respond with better bracketing options or maybe even HDR-capable sensors. That's why you need to keep the ball rolling: nurture this new market of HDR material, show them that this is a topic you care about - order at least one of these new HDR books!

Order Michael Freeman: Mastering HDR Photography
(recommended for pro shooters, emphasize on image quality and natural tonemapping)

Order Ferrell McCollough: Complete Guide to HDR Photography
(recommended for creative minds, looking for inspiration and hands-on guidance)

One-shot panoramas

2008-06-15T23:56:00.000-07:00

Fisheye lenses are awesome in delivering pristine quality. Just got the new Sigma 4.5mm for my Nikon D200, and now I get a full pano done in 3 shots. But that's about the end of the line. Some stupid law of physics prevents lenses to show more than 180° FOV.

That's why mirror balls are still in fashion for getting these quick-and-dirty HDR environment images done. Problem with mirror balls is: they're a royal pain to handle, the shoot requires a complicated 2-tripod setup, and they have a blind spot behind them. Also, you see the photographer's reflection in the center - so that's yet another useless spot.

Students from the Linköping University have figured out a smart setup, that overcomes these problems. They cut out a hole where the photographer's reflection is, and put in a lens to picture what would have been hidden behind the mirror.

Read the full paper here.

Let's see how long it takes until this idea turns into a product. Maybe next Siggraph? Photokina?

Similar mirrorball-on-a-stick lenses are the Kaidan 360 OneVR, the 0-360 Panoramic Optic, the VRi SurroundPhoto, the EGG photo306°, but none of them are this advanced. Yet. They might work great for real estate tours on Craigslist, but for VFX work we demand it to be more awesome. According to this reference page most of these current one-shot systems are even made of plastic.

June update

2008-06-04T22:22:00.000-07:00

Been terribly busy lately, so this time the Montly sIBL is a little late.
To make up for it, I put a brand new set together for you - this time even with a little rendering as thumbnail. This is really the way a sIBL set should work.

Oh, and while restarting the Flickr Gallery I noticed that almost 500.000 photos on Flickr are tagged with "HDR". Just 10 months ago there were only 150.000, looks like HDR is really taking off. Compared to back then, it seems the average quality is on a much higher level, too....

Panoramic Video

2008-05-27T22:06:00.000-07:00

Surprisingly compact device, it is. At least the head unit, the recording/blending box requires a backpack.

What do you get when you put 11 lenses on a camera, plug that into a realtime blending box, and combine it with some serious video streaming equipment? That's right - panoramic video! And if you'd want to take it to the next level, you'd craft your very own Flash Player to display immersive video on the web.

Well, a company called Immersive Media did just that, and boy - it's the coolest thing I have seen in a while! Might not be high dynamic range, but certainly related cutting edge panorama technology. And I can already think of a billion applications in the visual effects industry...

Play the movie below and drag your mouse for a full surround view!

They have plenty of great demos on the Immersive Media site.
Or check out the special surfer coverage on the Red Bull site!

Realviz joins the Autodesk universe

2008-05-07T09:56:00.000-07:00

Autodesk was on a shopping tour again, and they announced today that they aquired Realviz and all their software products.

This means what was formerly known as Realviz Stitcher, is called Autodesk Stitcher from now on. If you head over to www.realviz.com, it looks like Stitcher has always been a genuine Autodesk product.

In the past, Autodesk always tried to ensure a smooth transition with a newly snatched product line. This time - not so much. There are no more student versions available, and VTour, Retimer and Matchmover are no longer available. Actually, for the next week none of the former Realviz programs is available at all, because the online store is closed.

Ohhhh, Retimer plugin for Fusion - I miss you already (in fact, just used it today). And VTour was one of those promising programs, that I haven't had a chance to write about yet...

More info in the the official press release.

All new Smart IBL in May

2008-05-01T23:49:00.000-07:00

I hate deadlines, but I wouldn't get anything done without them either.

This time it was ACM SIGGRAPH, asking for all the material for this upcoming SIGGRAPH Class. And because Smart IBL should definitely be on there, the entire sIBL team was working really hard on updating all the sIBL Loader scripts. GO TEAM!

So, what's new?

sIBL-Edit is now available as Linux version, in 32 and glorious 64 bit.
Lightwave sIBL loader has a new thumbnail view and works on Mac and PC, v9.3 and up.
Maya sIBL loader supports mental ray production shaders and rayswitch in Maya2008.
3dsMAX sIBL loader works with mental ray, fixed VRay (again).
a brand new loader for modo is about to join the ranks, stay tuned...

As usual, here is also a new sIBL set of the month ready for you to download, and the race for the hottest HDR on Flickr has started over again...

Happy May!

This Week in Photography

2008-04-25T23:29:00.000-07:00

Wow, what a crazy episode!

It was almost intimidating to do my first podcast appearance among all these internet celebrities for, but definitely fun. Alex Lindsay asked me lots of questions about my book, and it seems the TWiP folks really liked it. They also have a Flickr challenge going where you can win the HDRI Handbook, as well as minor giveaways like Aperture and Lightroom. :) This show was really about some big announcements;

Alex announced DVGarage's dive deep into the new Aperture 2.1 SDK. First plugin is already out: dpMatte for greenscreen keys, coming up is Conduit (sweet nodal compositing), and also HDRToner - yes - for tonemapping right inside of Aperture. Lots of good stuff. Listen to the episode yourself!

The second big announcement came from me:

SIGGRAPH 2008 Class: HDRI for Artists

A nice little gang of presenters is coming together to teach about HDRI at Siggraph:
my friend Kirt Witte from the Savannah College of Art and Design, Hilmar Koch from ILM, Zap Andersson from mental images, Gary M. Davis from Autodesk, and of course, yours truly.
If you happen to be in LA for Siggraph, don't miss the show!

Google talk from the Grandmaster of HDRI

2008-04-11T12:07:00.000-07:00

Paul Debevec doesn't need much of an introduction - he is one of the founding fathers of HDRI. His latest research is so way out there, yet he has the incredible talent to explain everything so it makes perfect sense.

Watch this and prepare to be amazed:

If you want to see more detailed information about Paul's projects, visit www.debevec.org. Check out his upcoming events calender, he will be touring Germany next month.

Oh, and by the way - the Lightstage shown in this video is in fact out of the lab already. If you just want to rent one for your own production, you can do so. Without any R&D and handcrafting on your end, just a simple plug-and-play product from Aguru Images.

April Updates

2008-03-31T22:59:00.000-07:00

It's that time of the month again: Update time. Lots of updates, most of them from other folks:

Photomatix 3.0 is out

Available for Mac and PC.

Lots of new features:

support for the latest RAW formats
feature-based alignment
more accurate tonemapping preview
improved exposure blending

The most visible change is a "Workflow Shortcuts" palette with the most common tasks. Very handy, but in my opinion they shouldn't reinvent the wheel when a simple toolbar would have been just fine (and wasted less real estate on my screen).

Anyway, my friend Uwe Steinmüller has put together a full review on www,outbackphoto.com. Check it out, and grab your update!

XDepth Plugin for Lightwave

This is really great news. Not only because I happen to be a Lightwave user, and I can now save Gigs of drive space by using this space-saving HDR format for my big HDR panoramas. (We talked about XDepth before.)
No, the great thing about this is the demonstrated sign of commitment. Trellis Management Co. Ltd., as awkward this name sounds to me, has given away XDepth plugins for Photoshop and Lightwave within a single month. Now, if they would get it to work next month in Fusion, I'd be happy rendering all day long things I might not even need in HDR, and our systems guy wouldn't kick me in the back. Add Firefox, Lightroom, Aperture, After Effects, Maya, 3dMAX, XSI, Shake, Combustion, and [insert your app here], and we actually can call XDepth an image standard.

Last but not least - here is some news from the related frontier of digital imaging:

Greg Downing shoots 270 Gigapixel Panoramas

If you ever tried to shoot and stitch a single Gigapixel pano, you know that this is a painful and time consuming process. Shooting 270 of these bastards, in 3 1/2 months - unthinkable for mere mortals. Even for a veteran HDR/panoshooter like Greg Downing this is a project of crazy scale.
Read this amazing story on VRMag!

And yes, before you ask, of course there is a new sIBL of the month, and the race for the hottest HDR on Flickr has started all over again.

Have fun,
Christian Bloch

Sprechen Sie Deutsch?

2008-03-12T19:42:00.000-07:00

OK, so now that I have thousands of German readers, I finally gave in and translated most of the HDRLabs site to German. At least most of the static pages, don't expect this blog to be truly bilingual anytime soon... The language switch is done server-sided, so if your browser/system language is set to German, you should be switched automatically.

And I have a special treat for my English readers (which make up 40%, by the way):
You get a sneak peak tutorial chapter! How awesome is that?

March Roundup: The HDRI Handbook is coming home!

2008-03-01T15:29:00.000-08:00

An excellent German translation by Rudolf Krahm, Rainer Dorau and Almute Kraus

The German translation of my book is out now!

So all you crazy Germanic fellows, what are you waiting for - order "Das HDRI Handbuch" from Amazon.de now!

Yes, it is somewhat ironic that the book started out as my diploma thesis in German. But I promise - even if you are one of the thousands of people who downloaded and read my thesis for free, you will not be disappointed by the book! It's three times the pages, in much finer print, with tons of more images and written in a casual, less academic style. Some information in my thesis was plain wrong anyway - just glad my profs didn't notice :). Heck, back then tonemapping wasn't even a topic at all, and now it is a major content area with tutorials from two professional photographers.

Guess it's time to do a proper translation of this website as well...

New website section: Say hello to the Hardware Shopping List.

If you're looking for the panorama equipment, or new cameras with HDRI in mind, you will find just the right thing on this new Hardware Shopping List. Featured are all personal recommendations, nobody paid me to put their product in this list. Instead, each product links to the most helpful review I could find, and of course it features the popular vote system known from the Software Link List.

Also, there is a brand new sIBL of the month waiting for you, and the Hot-on-Flickr gallery just restarted today.

Check it out!

By the way - it still amazes me to see this gallery fill up so quickly. See, it filters only images uploaded since March 1st., yet it is filled with 99 images at 1 AM! Makes me wonder what the HDR upload per minute on flickr must be.... Usually there is a lot of fluctuation in this gallery within the first 10 days of a month, and then the very popular (and some very good ones) float atop and stick there.

Enjoy this update,
Peace!

XDepth: New Challenger is Ready to Rumble

2008-02-21T00:55:00.000-08:00

A new HDR file format seemingly popped out of nowhere, just when we were discussing HDPhoto here. XDepth is aiming at the same thing: efficient compression of HDR images, so they can be distributed over the web. Or take up less storage space - we all know how HDR files eat through your drive, especially when you're dealing with image sequences.

Admittedly, I was a little skeptical about this format. The publisher is very secretive about their encoding approach, sounds like the format is proprietary. And the publisher's name, "Trellis Management Co. Ltd.", doesn't really give me a warm fuzzy feeling either. They actually had another HDR format out for almost a year, called "CLARITY-HDR^TM

but aside from the initial announcement I haven't seen it anywhere.

That being said, here is the scoop: XDepth is amazing! It combines the best things of JPEG-HDR and HDPhoto: It's backwards-compatible with JPEG and instantly usable with a free Photoshop Plugin. And after an initial test, it even seems to beat both of them in the amount of compression. Well done, Trellis!

But first things first - here is what the Photoshop saver looks like:

XDepth's Photoshop Saver Dialog: Well organized and usable by mere mortals.

Notice the separation of HDR and LDR compression. When you save your image as XDepth file, the saver will actually make a regular 8-bit JPG, and hide the HDR data in the matadata. That's right - even though the native file extension is .xdp, you can just rename it to .jpg and it will open anywhere. In fact, the XDepth website itself is made of nothing but these renamed .xdp files, making it the first truly HDR online presence on the web.
In the context of this dialog, LDR quality sets the compression of this base-JPG, and the Gamma value is your crude tonemapping control, letting you choose how contrasty you want in this JPEG. The default value 2.2 corresponds to the default settings in Photoshop's 32-bit Preview.

The interesting part comes in when you re-open the file in Photoshop. Then all the hidden HDR data comes back, and find yourself in 32-bit mode.

Quick comparison, aimed at the best possible quality preservation.

So let's see how the format compares, using the good old Kitchen Window again.
To include my current favorite, Ward's JPEG-HDR, I pulled it up in Photosphere (for the lack of a Photoshop Plugin, which is in real life a deal breaker by itself).

It turns out, XDepth beats JPEG-HDR and HDPhoto in filesize, although it doesn't look quite as clean. "Lossless" in the saver dialog apparently means "perceptually lossless", not absolutely lossless. In that regard, XDepth will certainly not make OpenEXR obsolete for images that we still need to work with.

However, that isn't what XDepth is aiming at - it is more of a final output format, like JPEG. It is supposed to crunch stuff as small as it gets, while still looking acceptable.

Quick comparison, aimed at the best possible quality preservation.

And this is where XDepth's strength is at: Just a tiny wiggle on the quality slider, to 90/95%, will shrink that EXR from 5.7 MB to 344 kB. That's only 1/17th of the size!! And it still looks fine.
Just for the sake of it, I tried to get the HDPhoto to the same file size, and ended up at 48% quality. At this point, the image turns into cubist masterpiece of artifacts.

Bottom line is: XDepth offers an impressive compression ratio, and usability is very straight-forward. The format has all it takes to become the standard for high dynamic range JPEG, clearing the path for a smooth transition to the promised land of All Things HDRI.
However, the catch is Licensing and application support. For now, Trellis Management Co. Ltd. seems to be friendly enough to provide us the tools for free. My wild guess is, they won't make it all open like OpenEXR, instead they will tackle one application at a time and implement import/export plugins themselves. And then, in stage 2, when everyone calls for direct hardware support, they will ask camera and screen makers for licensing fees. I might be entirely wrong here, but if I'm not: Good luck, Trellis, I really hope you succeed! Your format is simply too nice to get lost in some legal grind.

So go grab the Photoshop Plugin from the XDepth website and start playing with it!

Hands-on with Microsoft's HD Photo

2008-02-11T18:03:00.000-08:00

Let's talk about HD Photo, the file format formerly known as Windows Media Photo (WDP), and just recently renamed in JPEG-XR. Confused? Yes, me too.

It's a new HDR format, that has been in the works for several years now. I mentioned it on pages 59/60 in my book, but for the lack of any single software that can actually read or write such files, it was excused from the file format comparison chart.
But now things have changed...

HD Photo works now!

Now you can download a free Photoshop plugin for Windows and OSX.
An unexpected and very generous move from Microsoft, not to leave the Mac folks out and even providing the source code. Very cool, thank you! Once installed, the Photoshop plugin works like a charm. While in 32-bit mode you get WDP as a Save option, and it gives you:

Variable wavelet compression, very much akin to JPEG2000
Alpha channels, that can have a separate compression
Embedded color profiles and metadata

For example, an OpenEXR file with an Alpha channel could be crunched down from 6 to 1.4 MB - with no visual losses whatsoever. It might not be mathematically lossless (although that is an option), but visually there it looks clean and artifact-free. And I can load that WDP image back into Photoshop, and start playing with the exposure slider. You can try for yourself: go ahead and download this image in WDP-format.

Pretty impressive. True HDRIs, small enough for email or display on the web. Begs the question:

Why isn't everyone using it?

I don't know. You would think at least Microsoft products take advantage of the HDR-data in an HD Photo. Ha, you're so wrong! Neither the HDView panorama viewer, nor Windows Live Photo Gallery can rock HD Photo right.

The same WDP in Windows LIve Photo Gallery
Question #1: How can that be, that there is no Exposure slider in the so called "Adjust exposure" section?
Question #2: When a Brightness slider is all you give me, why doesn't it reveal the blue sky?

They both are new products, both based on WDP as their native format. They just don't know how to deal with high dynamic range images, and so they simply do not work as expected.
Especially Live Photo Gallery was a disappointment, because after a horrifying setup procedure it simply doesn't work as advertised in Bill Crow's Blog. His example might not be such an extreme case like mine, highlights he recovers are still within the realms of what you get in a single RAW file.

If Microsoft doesn't fully utilize the strengths of HD Photo, why should anyone else do?

Maybe it was a pretty bold move to sketch out an entirely new format, and trying to rely on Microsoft's market position to push it through. Maybe Greg Ward was right, when he promotes a soft transition to HDR by providing a backwards-compatible JPEG format:

"Backwards-compatible HDR formats are a win-win for manufacturers and consumers alike. Easing the transition from 24-bit RGB to full dynamic-range and gamut capture, editing, and viewing has the potential to greatly accelerate market penetration. Early adopters would gain immediate access to an HDR world, while others would not be inconvenienced, and could even benefit from improved tone-mapping in their legacy content."

(From The Hopeful Future of HDRI)

Bottom line is: HD Photo works just fine, but only in Photoshop.

And since it is a brand-new format, support will have to be built up one-by-one.

Ward's (or should I say Dolby's) backwards-compatible JPEG-HDR works everywhere. Even though it is disguised as regular JPEG, and only Photosphere and pfstools can actually see the HDR data within. But I can upload a JPEG-HDR image to Flickr, and it behaves just fine. Nobody is inconvenienced, everybody can see it, it gets thumbnailed, and the Flickr people don't have to revamp their entire database system to support a brand-new file format.
But you, my dear HDR-savvy reader, you can just download the Original size image from Flickr, load it in Photosphere, save it back as EXR and tonemap all day long.

The Hopeful Future of HDRI

2008-02-06T21:32:00.000-08:00

Greg Ward, one of the most visionary imaging scientists, has published an excellent paper on the future of HDRI.

He gives all the reason why Digital Imaging is destined to evolve towards HDRI, and he outlines the plan how this transition will actually happen. Given the fact, that Ward developed half of the available HDR image formats, built the world's first HDR display, and is currently on Dolby Lab's salary list, this man certainly knows what he is talking about!

Give yourself the treat of total enlightenment and read his fascinating paper.

February Update

2008-02-02T09:46:00.001-08:00

This month I have quite a bunch of updates to the site:

Panorama Calculator

How many images do you need for a panorama? Can you streamline the process with a different lens? What if you'd choose less overlap than the "safe" standard 25% ? How does fisheye lens compare to a regular lens?
All these questions are easy to answer with the new Panorama Calculator in the tools section.

Picturenaut FAQ

Documentation is key for every software. Well, Picturenaut doesn't really have a manual, but this FAQ should answer most of your questions. None of the boring bloat stuff - only what you really want to know.

Check it out!

...and the regular monthlies

Back with a brand-new SmartIBL preset, nice and high-res. The Hot-on-Flickr gallery has been reset for February. And the Software Link Directory has been cleaned up to look a bit nicer in your browser.

Have fun,
Christian Bloch
Author/Webmaster/CG-Artist