Thursday, December 2, 2010

Dear Ol' sRGB?

A week now after the training course which I was part of, and still feel tired, mostly of everything. Just today, I woke up later than my usual time, plagued with congested nose. It is a slow and somehow boring week, despite my work on my photos, which was so-so actually, but the core of the problem, who or how, would bring my heart back from New York?

I've been working now and then in order to finish my second album of pictures from Ireland - Co. Tipperary, and somehow I'm almost done. Only one is left and the album is ready to be spread all over, and hopefully I can do this one picture today. Meanwhile, I'm having now a hard time with the Dining Room panorama, after fixing the Lounge panorama with lot of stepping down and compromises.

The Lounge of Thornbrook House.

In this final panorama stitching, I had to give up many hopes I had for this room, but at least I got the general shape in the picture without much loss of "interesting" details around the room. The following steps were stepped down:

  • Panorama stitched from JPEG files (not even 16bit TIFFs), because stitching HDR slides produced some artifacts caused by blending extremely dark with extremely bright areas.
  • Because of the above, I lost the chance to tone-map the HDR image as I like. Instead I had to tone-map everything in the beginning then stitch.
  • To reduce stitching errors radically, I had to give up the zenith and nadir completely. The zenith specifically was important for me because it had a crystalline light chandelier that I wanted to show its sparkles.
  • Henceforth, because of the above, I had to give up with creating a QTVR.

It is obvious now, from The Lounge panorama, and The Dining Room panorama, or even from old panoramas I've worked with, that my everlasting nemesis is generally, long straight lines. Such lines do not have much distinctive features making them hard to overlap accordingly by PTGui, my preferred tool for stitching as always. The Dining Room seems to be going on the same steps of the Lounge now, but I'm having a break from this panorama trying to do more single slides and images, not only from my recent visit to Ireland but also, for one image, from my previous visit in 2009.

The weirdest thing I've encountered so far is, tone-mapping HDR images in sRGB color space proved to be more attractive and sharper than tone-mapping HDR in ProPhoto color space! For those who do not know the difference, ProPhoto color space is wider and usually gives vivid colors for display rather than the regular and simple sRGB space. Everything goes back to Mostphotos website actually, when I noticed that images I'm submitting, whether tone-mapped HDR or simply RAW fix, are changing colors significantly on Mostphotos website.

 One of the images where the blue color was "killed" by change of space. 
It is apparently dark here but originally it is brighter in Photoshop. 
Photobucket, after a system upgrade, seem to gauge their acceptance for color 
spaces more than before as such change in colors was not noticed before from my side!

Of course, the first suspecion in such cases goes around the color space. Thus I decided to make a try out and submit my images in sRGB space and see and notice any changes in colors.
After that, I adapted for myself a new approach creating the HDR images, but it is lengthy. Despite the saying that merging HDR from original RAW files is better to include as much as possible of the dynamic range, I converted my files here to 16bit TIFFs and cleaned them a bit from the noise with slight sharpening by NeatImage, then saved those files. Note here in the process of converting the files from RAW to TIFFs by the Raw Converter (ACR), I've assigned the color space as sRGB and worked a bit on each slide of image to avoid out-of-histogram regions for each slide.
Next thing was using Photomatix to merge them to HDR, as I don't trust the capabilities of Photoshop in aligning images when I use the "merge to HDR" command there. I saved the HDR image as EXR for reference, and the surprise was when  I tried to tone-map. The image kept relatively sharp, nd gave out interesting vivacity of colors more than a ProPhoto tone-mapping would give out! Not only that, but the noise is significantly less and the image is relatively sharper than when I do it with ProPhoto. Since I care about the looks and not merely putting out with technical details for the sake of being technical, I'm considering now for real, going back to the rare ol' sRGB!

Image that went under experimentation.
The entrance of Inchagoil church ruins on Inchagoil island, Co. Galway.

I think right now it is the time to put my ego aside and work on the more humble sRGB just to get such significant colors and clarity from my HDR images. The first step was to try it again for real... on another image.

Cahir castle, yard entrance gate.
Don't pass under those dents!

This image proves again that sRGB in HDR merging is better, but I've noticed something now concerning the saturation of some colors. It was hard to make a vivid aspect of the grays and the blues by simply tone-mapping in Photomatix. This problem, however, could be solved using Photoshop's hue/saturation layers. My aim next step now is to try to merge directly the RAW files using sRGB space in Photomatix and see if this will work significantly in the same way. That way, I'll be shortening one step out, that is converting to TIFFs (although I do some noise cleaning in this step usually, but it is nice to try out how much noise will be added in my HDR directly from the RAW under sRGB).

Not all my HDR images, after all, are tone-mapped automatically and given vivid colors. I think this is an important aspect when dealing with HDR images; you have to know what you are dealing with and what are you trying to do. HDR technique isn't really all about "eye-catching" images, but it is just a tool. I try to keep this in my mind all the time.
One of the images that I experienced this aspect with was the picture of the field of corn, taken from over the bridge at the edges of Cashel town back in October;

Corn field in Cashel.

When I saw this picture again, I remembered the famous song, Fields of Gold, and hence I decided to work on it to give some resemblance to the title of that song, Fields of Gold! The main problem as you can see here, the day was foggy, heavily, and the colors aren't saturated much specially in yellows. Sure thing was to seek HDR solution here, but since we have a "picky" approach here to turn the day from foggy to sunny somehow, we can't really rely on automatic tone-mapping by Photomatix or any other software. We have to use the manual tone-mapping with adjustment layers and hue/saturation adjustments, in abundance.

Fields of Gold!

My skill in manual tone-mapping didn't progress much; I still have problems getting used to the tone-mapping curve in Photoshop. The "radius" and "threshold" parameters, although it is advised to not touch them at all, I can't get the hang of it to make a sharper image from my HDR slide. However, with exposure and saturation fixing manually, there was not much "curving" needed further.Just minor touch to increase the contrast between different regions. The artifacts, however, like halos around bodies is more pronounced in the original image when zoomed to 100%.

Also related to the talk about the HDR imaging, I've been looking for a reliable freeware for tone-mapping HDR images, and found some substitute, but none, so far, can really be a match for Photomatix, not in terms of quality only, but in term of easiness to use as well. The thing that really sparked this search is the memory issues and the weird squares showing on my Photomatix window (regardless of the memory issues) from time to time, preventing me from seeing the full picture and make good judgement or even move the sliders with easiness. Hence, I thought I might try some other programs and who knows, there could be really nice options out there undiscovered yet, and most importantly, free! I've encountered some programs, free- and shareware, but all in all, I couldn't depend on them completely to be a substitute for Photomatix. But some of them are good one way or another and kept them installed just in case. Some of these were:

  • Picturenaut: A freeware made by Marc Mehl and co-authorized by Christian Bloch (Blochi). They claim it is really memory-efficient (and designed specifically aiming at HDR panoramas). I've downloaded it (from here) and tried it, and I think it is indeed as they say! Memory-efficient! The main issue here is, from my perspective, is that Picturenaut is the good-boy type of tone-mapper. It has many controls and many different aspects of the tone-mapping, but generally it doesn't provide the potential to give those fancy looks or the grunge look to your HDR images. I didn't frankly test much of its other aspects like aligning images, but I do trust Blochi did take care such an issue. If you have an HDR image or panorama, and you want to be the old good-boy type with it and fix the issues with highlights and shades, and just give it the brilliant "normal" look, then this is yours. Of course, if you have memory issues, this could be the best for you. And it's free!!! (Don't hesitate to donate though, they are doing great job there!).
  • Qtfsgui (a.k.a. Luminance HDR): Another freeware. Frankly, I don't know what QTFS stands for, but the GUI is surely for "Graphical User Interface". This software has the potential of giving you the weird looking tone-mapped HDR images, but it is still under development and would need a really steep curve of learning, for me, to know what I'm doing. To tone-map an image, you would need to pick up an operator from the list of operators and work on the sliders to adjust the values as you like, to give the image the look you like. In case you don't know what are operators, let's say they are the type of algorithms or approach of tone-mapping your HDR image, and there are local ones (adjusting group of pixels or certain areas in your image) and there are the global ones (applying the algorithm to the whole image at once). When you choose an operator it gives a little description, but all in all it is not sufficient to know what you are doing with the operator. Every time you change a value of some factor, you need to click "apply" and a new window will be pop-up each time to see the latest changes to your image (and sometimes it gave an error and the program closed). It is the work and effort of one person, thus I can't say this is bad at all. The guy deserves some donations at least! You can get it from here.
  • DP HDR (Dynamic Photo-HDR): A shareware by Mediachance, and hence, you can expect it is advanced. The main feature of this tone-mapper it offers variety of operators and categorize them accordingly to local and global, and under each category there are sub-categories that are direct to the point; like "eye-catching" option for example. It extends further in controls giving you the ability to control the alpha channel itself, or the layer inside HDR which controls the luminance; you can blur it more, invert it and some other stuff, to give your image the drama needed. I can't describe all the options provided in this software but one way or another it is similar to Photomatix but with different names sometimes or more specific sliders. When merging into HDR, it gives you the option to do your OWN aligning (Cool! somehow!). It has also a built-in Noise Reduction tool (while Photomatix does that automatically) and gives you the chance to control it as you like and even brush off areas that you don't want it to be affected. So far though, I don't remember it supported OpenEXR format (.exr) but only the Radiance format (.hdr). One weird concidence though, I tone-mapped one image and saved it as 16bit TIFF, but in Photoshop it appeared completely different than what I saw in the software's window! Weird, but promising.
There had been other trials on some other programs but I didn't experience them enough to write something about them here, like FDR Tools (basic version is free while the advanced version is shareware), and easyHDR (shareware). The latter is a promising software and bears resemblance to Photomatix, but the question now is all about the memory issues in between all of the mentioned above. So far, I'll be using Photomatix, and I still feel I didn't grab it all in my mind yet.

After all of the mess above, you might be thinking I was busy with something for real, well, I was trying to. Pushing myself hard to do something out of nothing and forget some thoughts that invade my mind from time to time about life. My life, that is. I've been in the process of grasping some phrases or words in my mind and really want to write them down, yet, I can't really glue them together. My mind is scattered apart. Since my return from Ireland, I've become more isolated around myself and not able to interact much with people specially at work. The new lunar year is on the gates and the month of Muharram will start soon, announcing days of mourning and black clothing. It will be a period of silence for me, and I have to stop listening to the songs that I do listen to usually everyday. It's going to be hard and to be frank, my conservative education is against what I'm doing, but the turmoil around me wherever I go left me no choice but to let off the steam via music-listening. I just hope and wish I will be pardoned in this life and the one after...
All I hope for now, is to get rid of this annoying nose congestion.

Alayhá, šá ayná ðánúħ kay ayná yaħavt? Limaz má tixmaŧ ayná élaká yi xawant ayná e-ąasiy?

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