deno-png-dpi-reader-writer

Reader/Writer for png image's pHYs chunk.
A deno port of png-dpi-reader-writer.

Usage

Detect width, height and DPI for PNG image.

// buf: deno/Buffer
const { width, height, dpi } = await parsePngFormat(buf)

Write DPI for PNG image.

const ui8arr = await writePngDpi(buf, dpi)

Examples

Reader

$ deno run --allow-read ./examples/reader.ts ./examples/retina/7127a0c2a987ea50dbba0ebd6455c206.png
$ deno run --allow-net https://raw.githubusercontent.com/daiiz/deno-png-dpi-reader-writer/master/examples/reader.ts https://i.gyazo.com/7127a0c2a987ea50dbba0ebd6455c206.png

Result:

{ width: 1102, height: 994, dpi: 144 }

Writer

$ deno run --allow-read ./examples/writer.ts ./examples/non-retina/8d132d64902c1323ffa8ca688b2c40eb.png 72 > a.png

Tests

$ deno test --allow-read