Tool for images coding and chipering

!!!Warning!!!

• during encoding input image is rewritten with a new pallete of a specified size (2 as min, 257 as max)

Tool features:

• Encoding as palette-based image with the Floyd-Steinberg dithering. Palette is generated with median-cut algorithm
• AES128 encryption-decryption (length-preserving) for pixels data available (header data stays unchanged)
• Zstandard compression for pixels data available

Build:

cargo build --release

Usage:

exe [options] [input_file_path] [output_file_path] [palette_size(2..257 inclusively)] [base64url_key]

options:
    - i - info mode: input - existing [input_file_path], output - stderr (correctly shown only for not encrypted and not compressed images)
    - e - encode mode: additional input - [palette_size], output - saved [output_file_path] or stderr
    - d - decode mode: output - saved [output_file_path] or stderr
    - c - encryption-decryption flag: additional [base64url_key] arg at last position
    - z - compression-decompression flag
    - g - 16bytes base64url stdout key gen

Examples:

• image for encoding (143KB):

• ./target/release/rust_image-codec ecz image.png encoded.bin 256 dozR7XYsRBdDmHhHtRmCJg: *saved ./encoded.bin file (62KB)

• ./target/release/rust_image-codec dcz encoded.bin decoded.png dozR7XYsRBdDmHhHtRmCJg: *saved ./decoded.png image

• decoded image (145KB):

Encoded header format:

• first three bytes - image dimensions (both are 2-based)
• fourth byte - palette size (2-based)
• next 3 * {palette_size} bytes - rgb8 colors
• rest of bytes - pixels data as byte-sized palette indices