oxideav-pbm

Pure-Rust Netpbm (PBM/PGM/PPM/PNM/PAM) image codec and container for the oxideav framework. Covers all eight Netpbm magic numbers in one self-contained crate. Spec sources: the Netpbm man pages (pbm(5), pgm(5), ppm(5), pnm(5), pam(5)) — no external implementation source was consulted.

Decode

Magic	Name	Encoding	Channels	Bit depth	PixelFormat out
P1	PBM	ASCII	1 (1-bit)	1	MonoBlack
P2	PGM	ASCII	1	8 / 16	Gray8 / Gray16Le
P3	PPM	ASCII	3 (RGB)	8 / 16	Rgb24 / Rgb48Le
P4	PBM	Binary	1 (1-bit)	1	MonoBlack
P5	PGM	Binary	1	8 / 16	Gray8 / Gray16Le
P6	PPM	Binary	3 (RGB)	8 / 16	Rgb24 / Rgb48Le
P7	PAM	Binary	1-4 + 6 standard TUPLTYPEs	1-16	MonoBlack / Gray* / Rgb* / Ya8 / Rgba / Rgba64Le

Comments (# … LF) are tolerated everywhere the spec permits — both in headers and (for ASCII variants) in the body between samples. Any ASCII whitespace separates header tokens and ASCII samples. P1 accepts both canonical token style and whitespace-free digit runs.

Encode

Picks the closest binary form for the input PixelFormat:

Input	Output
MonoBlack	P4
Gray8	P5 (maxval 255)
Gray16Le	P5 (maxval 65535, on-disk samples big-endian)
Rgb24	P6 (maxval 255)
Rgb48Le	P6 (maxval 65535)
Rgba/Bgra	P7 RGB_ALPHA (maxval 255)
Rgba64Le	P7 RGB_ALPHA (maxval 65535)
Ya8	P7 GRAYSCALE_ALPHA (maxval 255)

Plain ASCII output (P1/P2/P3) is available via [encoder::encode_pbm_ascii] — the binary path is always preferred for size.

Round 1 deferrals

• User-defined TUPLTYPE strings (round 1 supports the six standard names BLACKANDWHITE, GRAYSCALE, RGB, BLACKANDWHITE_ALPHA, GRAYSCALE_ALPHA, RGB_ALPHA only).
• 16-bit GRAYSCALE_ALPHA is widened to Rgba on decode (no Ya16 variant in oxideav-core yet).

Registration

let mut codecs = oxideav_core::CodecRegistry::new();
let mut containers = oxideav_core::ContainerRegistry::new();
oxideav_pbm::register(&mut codecs, &mut containers);