RLA to PPM Converter

RLA is a raster image format developed by Wavefront Technologies in the mid-1980s for their Advanced Visualizer 3D rendering software, which ran primarily on Silicon Graphics workstations. RLA files store rendered frames with support for multiple channels beyond standard RGB — including alpha transparency, Z-depth, surface normal vectors, object ID, material ID, and other arbitrary data channels that compositing artists use to manipulate rendered elements without re-rendering. Each scanline is independently compressed using run-length encoding, allowing efficient random access to any row without decompressing the entire image. The format supports 8-bit, 16-bit, and 32-bit floating-point per channel, making it suitable for high-dynamic-range rendering output. RLA was a staple of visual effects production throughout the 1990s, used extensively in film and broadcast VFX pipelines alongside Wavefront's Composer compositing software. The format's successor, RPF (Rich Pixel Format), extended the concept further and was adopted by Autodesk 3ds Max, but RLA remains the earlier standard. One advantage is the multi-channel rendering data: unlike simple RGB image formats, RLA files carry per-pixel depth, normal, and ID passes that enable post-render effects like depth-of-field blur, fog, re-lighting, and object-level color correction without returning to the 3D application. This pipeline efficiency made RLA essential in early visual effects production. The format is recognized by Autodesk tools, Foundry Nuke, ImageMagick, and various legacy compositing applications.