Function encode 

pub fn encode(
    pixels: &[u8],
    width: u32,
    height: u32,
    num_components: u8,
    bit_depth: u8,
    signed: bool,
    options: &EncodeOptions,
) -> Result<Vec<u8>, &'static str>

Encode pixel data into a JPEG 2000 codestream.

Arguments

• pixels — Raw pixel data. For 8-bit: one byte per sample. For >8-bit: two bytes per sample (little-endian u16).
• width — Image width in pixels.
• height — Image height in pixels.
• num_components — Number of components (1 for grayscale, 3 for RGB).
• bit_depth — Bits per sample (e.g., 8, 12, 16).
• signed — Whether samples are signed.
• options — Encoding parameters.

Returns

The encoded JPEG 2000 codestream bytes (.j2c format).