pub fn rgba_to_rgb(rgba: &[u8], width: u32, height: u32) -> Vec<u8> ⓘExpand description
Drop the alpha channel of a tightly packed width * height RGBA8 buffer,
returning tightly packed width * height RGB8 (3 bytes per pixel).
silx’s raster image export (PlotImageFile.saveImageToFile) operates on an
(h, w, 3) RGB array; the PPM body carries RGB, so the readback’s RGBA is
reduced to RGB by discarding alpha.