sharp-apng

APNG(animated PNG) encoder and decoder for sharp base on upng-js.

Install

``bash
npm install sharp-apng
`

Usage

`js
const sharp = require("sharp");
const apng = require("sharp-apng");

(async () => {
// APNG to GIF
const image = await apng.sharpFromApng("./animated.png");
image.toFile("./output/apng2gif.gif");

// APNG to frames
const frames = apng.framesFromApng("./animated.png");
frames.forEach((frame, index) => {
frame.toFile(./output/apng-${("000" + index).substr(-4)}.png);
});

// GIF to APNG
apng.sharpToApng(
sharp("./animated.gif", { animated: true }),
"./output/gif2apng.png"
);

// frames to APNG
apng.framesToApng(
[
sharp("./frames/0000.png"),
sharp("./frames/0001.png"),
sharp("./frames/0002.png"),
],
"./output/animated.png"
);
})();
`

API

$3

Create instances of sharp from APNG frames.

- input (String | Buffer) - A String containing the filesystem path to an APNG image file, or a Buffer containing APNG image data.
- resolveWithObject Boolean _(optional)_ - Return an ImageData containing frames (an array of instances of sharp) property and decoding info instead of only an array of instances of sharp. Default by false.

Returns Sharp[] | ImageData - Return an array of instance of sharp, or an ImageData containing frames (an array of instances of sharp) property and decoding info.

$3

Create an instance of animated sharp from an APNG image.

- input (String | Buffer) - A String containing the filesystem path to an APNG image file, or a Buffer containing APNG image data.
- options DecoderOptions - Options for encode animated GIF and create sharp instance.
- resolveWithObject Boolean _(optional)_ - Return an ImageData containing image (an instance of sharp) property and decoding info instead of only an instance of sharp. Default by false.

Returns Promise - Resolve with an instance of animated sharp, or an ImageData containing image (an instances of sharp) property and decoding info.

$3

Options for encode animated GIF and create sharp instance.

- sharpOptions Number _(optional)_ - Sharp constructor options.
- delay (Number | Number[]) _(optional)_ - Delay(s) between animation frames (in milliseconds).
- repeat Number _(optional)_ - Number of animation iterations, use 0 for infinite animation. Default by 0.
- transparent Boolean _(optional)_ - Enable 1-bit transparency for the GIF. Default by false.
- maxColors Number _(optional)_ - Quantize the total number of colors down to a reduced palette no greater than maxColors. Default by 256.
- format ("rgb565" | "rgb444" | "rgba4444") _(optional)_ - Color format. Default by rgb565.
- rgb565 means 5 bits red, 6 bits green, 5 bits blue (better quality, slower)
- rgb444 is 4 bits per channel (lower quality, faster)
- rgba4444 is the same as above but with alpha support
- gifEncoderOptions Object _(optional)_ - gifenc GIFEncoder() options.
- gifEncoderQuantizeOptions Object _(optional)_ - gifenc quantize() options.
- gifEncoderFrameOptions Object _(optional)_ - gifenc gif.writeFrame() options.

$3

Contains the following decoding info:

- width Number - The width of the image, in pixels.
- height Number - The height of the image, in pixels.
- depth Number - Number of bits per channel.
- ctype Number - Color type of the file (Truecolor, Grayscale, Palette ...).
- pages Number - Number of frames contained within the image.
- delay Number[] - Delay in ms between each frame.
- frames Sharp[] _(apng.framesFromApng() only)_ - Instances of sharp from APNG frames.
- image Sharp _(apng.sharpFromApng() only)_ - Animated sharp instance.

$3

Write an APNG file from sharps.

- images Sharp[] - An array of instances of sharp.
- fileOut String - The path to write the image data to.
- options EncoderOptions _(optional)_ - Options for resize frames and encoding APNG.

Returns Promise