FAQ
Is the command line difficult to use?
Once installed, it’s a single command. On macOS you can install a Finder Quick Action to get a right-click “Process with PPRC” option, no terminal needed.
Why might I want to use a .raw workflow with my Pakon, why not just save from PSI?
PSI produces decent images and some people prefer using them as-is. But PSI works with more data internally and then discards much of it when saving to 8-bit. The images are also heavily processed with Kodak’s automatic adjustments. PPRC preserves the full sensor data and gives you a neutral starting point with more dynamic range and detail to work with. See the comparison →
Why use TLXClientDemo instead of PSI for raw files?
PSI can only export 8-bit files, even when exporting “raw” TIFFs. This limitation shows up most often as visible banding in the highlights. TLXClientDemo’s planar raw output preserves the full sensor data. See the highlight issue →
Can’t I just open the planar raw files in Photoshop?
You can, but you’ll have to manually specify the image dimensions, channel count, bit-depth, and header offset each time, then save out to a TIFF. PPRC detects all of this automatically (from file headers or known file sizes) and processes an entire directory at once.
Can I use my own inversion tool?
Yes: run with --mode raw to get linear 16-bit TIFFs without orange mask removal, ready for Negative Lab Pro, ColorPerfect, Vuescan, or any other tool. That said, it’s worth trying PPRC’s own inversion first, especially if you haven’t tested it since the 1.0 ground-up rewrite.
Why is the output so flat?
This is by design. PPRC’s goal is to preserve as much data as possible from the raw file, so the default output is intentionally neutral and flat, with plenty of headroom to edit, rather than a punchy, finished look. If you want something closer to a final image straight out of PPRC, try a stronger contrast stretch with --clip 0.1.
How does the color inversion work?
PPRC comes with its own inversion pipeline tuned for Pakon raw scans. All images in a batch are analyzed together to compute a shared color profile. This produces more consistent results across a roll than analyzing each frame individually.
For best results, process a whole roll together when possible instead of splitting it into small batches. The shared analysis and outlier-frame rejection both work better with more context from the rest of the roll.
During analysis, the very brightest and darkest pixels within each frame are ignored so that dust spots or specular highlights don’t skew the profile. Outlier frames (e.g. backlit shots with very different color characteristics) are automatically excluded from the shared profile so they don’t throw off the rest of the roll.
You can tune the inversion behavior with CLI options or save your preferences in a global config file.
PPRC 1.0+ uses a purpose-built inversion engine to handle color analysis and orange mask removal. Prior to version 1.0 (released June 2026), PPRC used the negfix8 shell script (which relied on ImageMagick) for inversion. That approach was slow (a 37-frame roll took around 2.5 minutes), produced less consistent results due to per-image analysis only, was easily skewed by large dust spots, and required ImageMagick to be installed separately. The current pipeline is fully self-contained, around 40–50x faster for the same workload, and produces significantly more consistent results thanks to whole-roll analysis and automatic outlier frame rejection.