interface IdatChunk
extends Omit<PngChunkUnknown, "type" | "data">

Refined IDAT (Image Data) chunk structure.

The IDAT chunk contains the compressed image data. Multiple IDAT chunks can appear in a PNG file, and their data should be concatenated before decompression.

Examples

Example 1

import { assertEquals } from "@std/assert";
import type { IdatChunk } from "@binstruct/png";

const idat: IdatChunk = {
  length: 100,
  type: "IDAT",
  data: {
    header: {
      compressionMethod: 8,
      compressionInfo: 7,
      fcheck: 1,
      fdict: 0,
      flevel: 2,
    },
    uncompressed: new Uint8Array([4, 5, 6]),
    checksum: new Uint8Array([0x12, 0x34, 0x56, 0x78]),
  },
  crc: 0x87654321,
};

assertEquals(idat.type, "IDAT");
assertEquals(idat.data.header.compressionMethod, 8);

Properties

type: "IDAT"

Chunk type identifier, always "IDAT"

data: ZlibUncompressedData

Decompressed zlib data structure

Usage

import { type IdatChunk } from ".";