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 not just use PSI's built-in saving?

PSI produces decent images and some people prefer using them as-is. But PSI works with 16-bit data internally and then discards half of it when saving to 8-bit. The images are also heavily processed with Kodak's automatic adjustments. PPRC preserves the full 16-bit data and gives you a neutral starting point with more dynamic range and detail to work with.

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 artifacting and quantization in highlights. TLXClientDemo's planar raw output preserves the full 16-bit data.

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.

How does the color inversion work?

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 May 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, 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.