PNG_Utils is a PNG decoder and collection of useful functions to read, parse, and edit PNG files in pure JS without the need for Node.
Extracting one 64x64 tile from the below tilesheet:
function foo(evt) {
const myPNG = await new png(evt);
const decompressedData = await myPNG.decompressIDATData();
const unfilteredData = myPNG.reverseFiltering(decompressedData);
const subImage = myPNG.subImage(unfilteredData, { x: 64, y: 64 }, { xMargin: 0, yMargin: 0 });
} //With event
function foo(evt) {
const myPNG = await new png(evt);
}
//Without event
function foo(file) {
const myPNG = await new png(file);
} function foo(evt) {
const myPNG = await new png(evt);
const decompressedData = await myPNG.decompressIDATData();
const unfilteredData = myPNG.reverseFiltering(decompressedData);
const subImage = myPNG.subImage(unfilteredData, { x: 64, y: 64 }, { xMargin: 0, yMargin: 0 });
}