codec / split · 1→2 / lossless

nodata

Keep missing samples out of the predictor.

nodata separates a raster into filled values and a validity mask. Missing positions borrow a nearby valid value, so later predictors see a continuous surface instead of a sudden jump. During decoding, the declared nodata value or NaN is restored wherever the mask marks a hole. Put this codec before quantization, and use it only on tiles that contain nodata.

ctid

0x72D70C

header

the nodata pattern at the sample width

modes

every NaN · one declared sentinel

widths

8 · 16 · 32 · 64-bit samples

decode

branchless select, values where the mask keeps, pattern where it discards