CAQuest - Profiling Functions

[andrewj]

This page is the new home for CAQuest, as the old Bibble forums have been completely wrecked by spam, and it was also time to bring the B5 and ASP versions together in a single thread.

CAQuest has five separate settings-management functions:
1. Lens correction settings profiling by lens, focal length and aperture,
2. Noise/sharpening profiling by camera and ISO,
3. Settings backup and updating for B5 XMP files before use in ASP
4. "Expose to the Right" exposure adjustments
5. Automatic correction of lens geometry for Micro Four Thirds cameras (experimental)

Lens Correction
CA Quest manages Chromatic Aberration correction for zoom lenses, allowing you to build up a "profile" of the correction required at each point in the lens' zoom range, and interpolating estimated values for points in between. This is very useful if you do a lot of shooting with entry-level or "mid-range" zooms, which typically require significant, and varying, CA correction at each end of the zoom range, but relatively little in the middle. It should also work well for compact cameras with zoom lenses.

CAQuest also supports Aperture-specific profiling and control of the Vignette correction as well as the main CA values.

Note that CA Quest doesn't implement any processing filter itself, it simply automates use of the standard Bibble CA correction function found on the "Detail" tool tab.

Usage is hopefully fairly self-explanatory. When you make an image active, the plugin reads the lens and focal length information, and looks them up in the correction database. If it can find either an exact match or sufficient information to propose a pair of CA values, it writes these into the "Suggested" line. If "Correct Automatically" is checked, or "Apply" is clicked manually, then Bibble's CA function is enabled with the suggested values.

To build up your lens profile, simply manually adjust chromatic aberration in the Bibble/ASP Detail tab (make sure CAQuest's "Correct Automatically" option is not set when doing this), and when you're happy with the correction, click "Save" in CA Quest.

Bibble's CA correction has an unfortunate side-effect that it currently puts a fine stripe of red or blue down one edge of the picture. CA Quest can also automatically correct for this. If "Crop Edge Pixels" is checked, then it will also set a very small crop on the image (typically about 4 pixels from each edge on an 18megapixel file). This won't override any existing crop, and you can disable the applied crop if you wish.

Aperture Matching

To use aperture matching, you have to install Phil Harvey's exiftool to build a database of your images and their Aperture and ISO values. You must install exiftool on your default path, or in the same directory as the main Bibble/ASP executable (e.g. bibble5.exe). To download and install exiftool, see http://www.sno.phy.queensu.ca/~phil/exi ... stall.html.

To build the exif database, just click the "Update" button next to the checkbox "Extended Image Info Database", and choose a directory which contains your images. This should then kick off a console process running exiftool. If successful, there will be a new subdirectory in your Bibble/ASP data directory called "CAQuest cache", containing a number of small .xml files, one for each image with a distinct date/time. (You may see a few warnings from exiftool - these are for duplicate files, or files with the same date/time to within 1s).

You can re-run the update at any time, or for any number of different image directories, although the database directory may get quite large if you process all your historical files. You can also delete the database and re-create it at any time if you want to tidy up a bit. Just don't delete the file CAQuestData.xml in the main directory, which contains your profile settings!

If the database has been created properly, when you select an image from the directory structure you processed, CAQuest should show the right aperture value and "image found" in green. If not, CAQuest will shown "Image not found" in red.

Aperture matching is "fuzzy", so CAQuest will use a profile with an exact focal length and aperture match in preference, but will use data for a different aperture if no better match exists. Vignette correction is only turned on if a non-zero vignette strength is set.

Noise/Sharpening Profiling
Hopefully this is pretty self-explanatory. You can assign a preset with your preferred noise and sharpening settings to each combination of camera and ISO you use. When a new image is loaded CAQuest will recall this assignment, and optionally apply the settings automatically. If you have not yet recorded a profile for the exact ISO value it will assign the closest match.

CAQuest can apply presets including any Bibble built-in settings, and also those for Spoilerhead's plugins such as Wavelet Sharpen and Denoise. It can be extended to other plugins but the developer will have to include a couple of lines of code in their plugins to share their group ID.

Settings Backup and Updating (ASP version only)
This works through a selected directory containing B5 XMP files, and applies a set of options to backup the settings and update some of them:
1. Creates a backup of the unchanged XMP file with a .B5 extension
2. Creates a backup of the B5 settings within the existing XMP as a new version cloned from the current master
3. Updates any "andrewj" settings to match the new "CAQuest" group name

Each of these steps is optional.

Note that the backed-up and updated XMP files appear to be smaller than the B5 originals. This is because some whitespace is stripped out of the XML when the files are saved. However all the information is retained, B5/ASP open them without problems, and if you make any change then B5/ASP save the files in their standard format.

I'm also working on a fifth option in this space, to apply a user-defined preset to adjust the B5 colour settings so that the ASP version starts from a similar look to the B5 one. This is work in progress- watch this space.

Exposure Adjustments
If you follow the "Expose to the Right" method, then CAQuest can automatically apply the initial post-processing adjustments, adjusting the exposure value to correct for your positive exposure compensation at the time of shooting (with a camera-specific offset if you wish), and then turning on either the ASP autolevel function or Roland's autolevel plugin. If you want to use the latter feature you will need version 0.3 or higher of Roland's plugin.

As always, CAQuest is designed to automate initial defaults, and then it's over to you to manage image-specific adjustments.

Micro Four Thirds Lens Correction
At the moment Bibble and AfterShotPro can't apply the same corrections to Micro Four Thirds (MFT) shots that are applied in camera, with the result that most require significant effort to correct geometic errors. The correction parameter data is stored with the RAW file, but although there's no obvious reason why not, Panasonic and Olympus have not published the specification for this data.

I have done some work to build parsing of this data into CAQuest. However although getting the raw data is fairly straightforward I have discovered that the algorithm is much more complex than we thought, and seems to vary from lens to lens. We therefore have a separate thread running to try and understand how the data is interpreted.

Details can be found on my website at http://www.andrewj.com/mft, with a discussion on the ASP web board at http://forum.corel.com/EN/viewtopic.php?f=96&t=47747

Downloads
Here are the latest version downloads:

[andrewj]

I've just updated the ASP version so that it works stably under the latest beta builds of ASP. This has been tested with 1.0.1.30 under all three platforms. Please note that if you "reset" an image with Ctrl+R, then CAQuest will not run on that image until you restart ASP. This is a known bug due to some oddities in ASP after a reset for which I haven't yet found a work-around. If you use CAQuest's own "Reset" button things should be OK.

[andrewj]

Hi All,
Just a note that I am unlikely to provide further developments or support for CAQuest. I have switched my main image processing to CaptureOne, and a copy of B5 and the existing version of CAQuest is adequate for the rest. I will continue to make the plugin available here and on my website, and I'm happy to answer the odd email query.

Thanks to all those who supported this endeavour!

Andrew