8/5/2023 0 Comments Fastrawviewer serialHowever coding in Kodak SLRs was done with this compression in mind so the white levels cut off quite early in a processing (effectively by applying a compressing curve). Initially I came across it when was writing the remap software - obtaining really raw data proved a bit elusive for SLRs and with typical approach (exposing sensor to uniform lit area near saturation point to calculate the defect map) this compression actually ended up hiding some defects. I just don't like throwing up the data - hence my interest. This is not just Kodak specific - its used by Sony and a few of other camera manufacturers. Regarding the Kodak compression method, it's a well known tecnique used also in pro audio. Respect for you impressive reasearch work on this topic. I'm interested in your full-range modification (not tested yet) as the non-linear behaviour near saturation may provide an interesting effect (one could always shot intentionally at a lower level if he doesn't like the effect). Above 90% non linearity increases severely.Ģ) it's a common tecnique to set the max level (0dB) of a converter below the real max even with perfectly linear converters, to provide some headroom for overdrive (talking audio slang here, but the same applies to other fields of signal processing). Regarding the max value set at 3700, there could be two reasons:ġ) the linear working range for this specific sensor is from 0% to 90% (with 3% drift) according to the sensor data sheet. As the signal level drops both technologies tend to similar, but lower, S/N values.Ĭhange 16/12 above with 12/10 and the same applied to the Kodak hardware/software. Note that the S/N is just the theoretical maximum when you use all the bits available. The S/N would be still 96dB for linear while the log version is approx (not exactly) 12*6.02 -> 72dB. The dynamic range for the 16bit linear would be 6.02*16 -> 96dB, same for the compressed version. This so called "log quantization" has exactly the same dynamic range as the linear uncompressed version, but a lower max S/N ratio. Since the 80's the DAT tape, beside the normal 16bit linear mode, had an extended play mode obtained by reducing the sample rate AND compressing 16bit to 12bit by using a log/exp curve (same as Kodak). Specifically there's an interesting collection of enums (along with their symbolic identifiers), which seem to cover every configurable parameter and allowed value ranges. zip files containing the devkit were not cached by the Wayback Machine, however part of the documentation is still present, as pdf files. If you navigate the developers area at the Kodak site through the WaybackMachine you can reach the devkit download page. Also, I think you asked for the DCS devkit elsewhere in this forum. The most important thing is that it fully supports 12 bit lossless files produced by firmware 5.4.10 (including preview displaying). It displays raw data (not only previews) really fast. It is quite a bit more than a viewer - file evaluation, sorting and XMP labeling for Lightroom and ACR. The Fast Raw Viewer has been released in first beta version ( announcement here). And for the rest of the Photodesk abilities - FRV is not the raw processor. In browsing+evaluating+sorting files FRV leaves Photodesk far behind. Browsing folders - Photodesk also shows thumbnails which are also demosaiced and downsampled to 1/12th of the original size. In fast processing mode Photodesk does not open or show the raw file - it shows a raw preview which is main raw demosaiced and downsampled to 1/6 of original size. DCR file contain 3 pieces of data: a fully sized raw data in Bayer format, a downsampled (1/6th of original) demosaiced RGB preview (not whitebalanced so a kind of raw) and downsampled (1/12th of original) demosaiced RGB thumbnail. Really? In similar conditions? Remove the fast processing in the View menu option (set it to Better instead of Faster) and then compare the speed please.Ī brief explanatory - each. I downloaded and have given it a fair run using 10 different files but to be very honest - I much prefer Kodak PhotoDesk - I also found it slower at opening a file compared to the Kodak offering.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |