Thursday, June 11, 2015

Leica Q (Typ 116) raw file (DNG) analysis

As usual when new Leica cameras come out, I took a quick look inside a DNG from one of Leica's new Leica Q (Typ 116) cameras:
  1. The camera is using what appears to be production software - version 1.02.
  2. The camera name shows as "LEICA Q (Typ 116)"
  3. The image data is 14-bit. There is no compression used in the DNG I looked at. 
  4. The DNG version is 1.4, with a "backward version" of 1.3. There is a reason for this - DNG 1.3 allows for opcodes, which Leica use for lens correction.
  5. In the DNG I looked at, which was shot with a "28.0 mm f/1.7" lens, lens correction is done by a single "WarpRectilinear" operation in the DNG. 
  6. In addition to the lens correction op code, there is also a "FixBadPixelsConstant" opcode, whose function is exactly as the name states. This is not something that I've seen in a Leica DNG before. It's not clear whether this is sensor specific (i.e., different Q's would have different corrections) or common to all cameras of this model.
For the Leica purists, something that's worth noting is that the lens is quite heavily corrected in software. Below are uncorrected and corrected version of the same image - note the distortion and quite heavy corner vignetting. (Image from

Sunday, May 3, 2015

Leica M Monochrom (Type 246) raw file (DNG) analysis

As usual when new Leica cameras come out, I took a quick look inside a DNG from one of Leica's new Leica M Monochrom (Type 246) cameras:
  1. The camera is using what appears to be production software - version
  2. The camera name shows as "LEICA M MONOCHROM (Typ 246)"
  3. The image data is 12-bit. There is no compression used in the DNG I looked at. The data is packed, four 12-bit values in 6 bytes, as is the case for the Leica T.
  4. The DNG version is 1.3, with a "backward version" of 1.1. There is nothing in the file that goes beyond the DNG 1.1 specifications; no opcodes, etc.
  5. The DNG is encoded as "LinearRaw" ("PhotometricInterpretation: LinearRaw"), as was the original Monochrom. The way the DNG spec works, you can either set that to CFA (aka a Bayer array type camera) or to LinearRaw. And this sure isn't a CFA camera.
  6. There are a few EXIF string fields that aren't properly terminated. This isn't usually a problem as most software will still be able to correctly read the fields, but it's kind of sloppy work by Leica.
Generally, the DNG seems to be quite standard - it happily works with current versions of all of my software - PhotoRaw, AccuRaw and AccuRaw Monochrome "out of the box".

It's a little surprising that the file is 12 bit. Actually, with a white level of 3750, true bit depth is slightly less than 12-bits. This is lower than the 14 bits of the original M Monochrom, although in practice its very unlikely that anyone will notice a difference.

A fairly frequent complaint about the original Monochrom and one that seems to again be coming up with regard to the new one is that the images appear flat. Something that I mention back when the original Monochrom came out is that there is one slight side effect of LinearRaw. When ACR or Lightroom load a normal raw, they apply a tone curve by default. However, with a LinearRaw, they don't. (AccuRaw, AccuRaw Monochrom and PhotoRaw do apply a tone curve by default, btw.) There is no law as to whether tone curves on monochrome images are required or not, but when comparing images, it's important to compare apples to apples.......

Tuesday, February 10, 2015

NDSR Boston chooses pcdMagic for Kodak Photo CD conversion

I don't often talk about pcdMagic because, well, there's seldom much new to say about it. For those that don't know, pcdMagic is my software package for converting old Kodak Photo CD images to modern formats. It's available for both Mac OS X and Windows, and runs on the latest 64-bit versions of both OS's. Photo CD was very popular in the early 90's and a LOT of images were converted back then. Unfortunately, Kodak subsequently abandoned the format. Today, it's actually quite hard to convert Photo CD images. Most of the major packages (e.g., PhotoShop, Lightroom, etc) no longer support Photo CD at all, and the packages that do still have some kind of support have really bad support - they typically only support low resolution images, they blow highlights, and get the color wrong. Take a look here and here for more detail on why these problem exist.

pcdMagic is custom built just for Photo CD images, and incorporates equivalents to Kodak's original proprietary color profiles, so pcdMagic gets color, highlights, etc., exactly right, the way Kodak intended back in the day. To my knowledge, pcdMagic is the only software package available for modern operating systems that can do so. As such, pcdMagic is frequently used by museums, art galleries, etc to convert their images.

But don't take my word for it. NDSR Boston recently performed a very detailed comparison of the various options for converting Photo CD images. To quote from their website, "The National Digital Stewardship Residency is a program designed to develop the next generation of stewards to collect, manage, preserve, and make accessible our digital assets by building a small cohort of residents."

While the comparison is very detailed, complete with histograms, color comparisons, etc, the result was simple - to quote from NDSR Boston, "pcdMagic is our tool of choice". You can read the whole comparison here.

Friday, February 6, 2015

PhotoRaw 4.2.1 is available with lots of new camera support

PhotoRaw version 4.2.1 is now available on the Apple App Store with new camera support including the Sony A7 II (ICLE-7M2), Sony QX1 (ICLE-QX1), Panasonic DMC-CM1, Pentax K-S1, Olympus E-PL7, Fuji S1, Kodak C330, Leica D-Lux (Type 109), Leica V-Lux (Type 114), Samsung NX300M, Samsung NX3000

Wednesday, November 26, 2014

The iOS 8 raw+jpeg bug is fixed

I previously wrote about a nasty bug in iOS 8 that prevented PhotoRaw from accessing any images that were shot as raw+JPEG.

Apple haven't fixed the bug - indeed, they have shown no interest at all in either fixing it or providing a workaround - but I'm pleased to say that as of version 4.2.0 of PhotoRaw, this shouldn't be a problem anymore. I've rewritten a large portion of PhotoRaw's image importing code to use an entirely different mechanism for importing under iOS 8. Of course, that mechanism doesn't exist under iOS 7 and earlier, so PhotoRaw now has a separate code path for iOS 8.

The version of PhotoRaw with the fix is on the App Store now, and a fixed version of PhotoRaw Lite will also be there as soon as Apple approve it.

Sunday, November 16, 2014

dcpTool and the DNG SDK on Linux

While Adobe's DNK SDK has been a great asset for the imaging world, allowing all sorts of useful open source software, including my CornerFix and dcpTool packages, as written it only supports Windows and OS X. This is for good reason - Adobe is a commercial organization, and the vast majority of software for commercial use is one of either Windows or OS X.  So there wasn't much point in Adobe spending a lot of time and energy getting the SDK running on Linux.

Fortunately, there are folks that are willing to take on challenges like this. "Cellstorm" has documented how to get dcpTool up and running on Linux in an article: DNG tools in Linux. This ported version can be used with Elle Stone's dcraw-float package. The dcraw-float package has a number of improvement relative to the base version of dcraw, including the ability to use DNG camera profiles.

Thursday, November 13, 2014

AccuRaw support for the Canon 7D II, SX60 HS, G7 X and Fuji X100T

So you can stop emailing me :)

The versions of AccuRaw and AccuRaw Monochrome on the App Store as of this morning (V2.2.8) have support for the Canon 7D Mark II, Canon SX60 HS, Canon G7 X and Fuji X100T.

PhotoRaw will also have support for all those cameras in a few days; this time round PhotoRaw is lagging by a few days because of some user interface tweaks to better support the iPhone 6 and 6+.