jParser: анализ двоичных файлов работает просто

-module(parse_ico).
-export([parse_ico/1]).

parse_ico(FileName) ->
	{ok, File} = file:read_file(FileName),
	<<Reserved:16/unsigned-integer-little,
	Type:16/unsigned-integer-little,
	ImageCount:16/unsigned-integer-little,
	Images/binary>> = File,
	{{header,
	  {reserved, Reserved},
	  {type, Type},
	  {image_count, ImageCount}},
	 {images, parse_images(Images, ImageCount, [])}}.

parse_images(_, 0, Result) ->
	Result;
parse_images(ImagesBin, ImageCount, Result) ->
	<<Width,
	Height,
	PaletteCount,
	Reserved,
	ColorPlanes:16/unsigned-integer-little,
	BitsPerPixel:16/unsigned-integer-little,
	Size:32/unsigned-integer-little,
	Offset:32/unsigned-integer-little,
	Content/binary>> = ImagesBin,
	{ok, Palette, PixelsBin} = parse_palette(Content, PaletteCount, []),
	{ok, Pixels, NextImgBin} = parse_pixels(PixelsBin, BitsPerPixel, Width, Height),
	Image = {
	  {width, Width},
	  {height, Height},
	  {palette_count, PaletteCount},
	  {reserved, Reserved},
	  {color_planes, ColorPlanes},
	  {bits_per_pixel, BitsPerPixel},
	  {size, Size},
	  {offset, Offset},
	  {content, {
		{palette, Palette},
		{pixels, Pixels}}}},
	parse_images(NextImgBin, ImageCount -1, [Image | Result]).


parse_palette(Binary, 0, Result) ->
    {ok, lists:reverse(Result), Binary};
parse_palette(<<R, G, B, A, Rest/binary>>, Count, Result) ->
    parse_palette(Rest, Count - 1, [{R, G, B, A} | Result]).

parse_pixels(PixelsBin, BitsPerPixel, Width, Height) ->
	CurImageSize = trunc(BitsPerPixel * Width * Height / 8),
	CurRowSize = trunc(BitsPerPixel * Width / 8),
	<<MyPixels:CurImageSize/binary, NextImgBin/binary>> = PixelsBin,
	Pixels = [lists:flatten([[Px2, Px1]
							 || <<Px1:BitsPerPixel, Px2:BitsPerPixel>> <= Row])
			  || <<Row:CurRowSize/binary>> <= MyPixels],
	{ok, Pixels, NextImgBin}.