example of using jimp and gifwrap to resize and crop gif to gif

[Welby O.]

Hi,

Does anyone have an example of using jimp and gifwrap to resize and crop gif to gif.

Thanks in advance

[Jeff Bonnes]

This isn't exactly what you are looking for, but these (typescript) functions can replace Jimp.read and Jimp.getBufferAsync to allow you to convert the first frame of a gif into a Jimp image and back to a buffer.

We use it like:

readImage(imageUrl)
.then((image) => image.cover(size.width, size.height))
.then((image) => getBuffer(image))
.then((imageBuffer) => {
  // now you can write the image somewhere
});

Note: will only work with the first frame....

/* This is a way of handing Jimp.read that will also take gif format.
   Ideally, we wouldn't need this, but Jimp cant handle gifs natively */
const readImage = (imageUrl: string): Promise<Jimp> => {
  var promise = new Promise<Jimp>((resolve, reject) => {
    Jimp.read(imageUrl)
      .then((jimp) => {
        resolve(jimp);
      })
      .catch((err) => {
        if (err.toString() === 'Unsupported MIME type: image/gif') {
          GifUtil.read(imageUrl)
            .then((gif) => {
              let image = GifUtil.copyAsJimp(Jimp, gif.frames[0]);
              resolve(image);
            })
            .catch((giferror) => {
              reject(giferror);
            });
        } else {
          reject(err);
        }
      });
  });
  return promise;
};

/* This is a way of handing Jimp.getBufferAsync that will also handle gif format.
   Ideally, we wouldn't need this, but Jimp cant handle gifs natively */
const getBuffer = (image: Jimp): Promise<Buffer> => {
  var promise = new Promise<Buffer>((resolve, reject) => {
    image
      .getBufferAsync(image._originalMime)
      .then((buffer) => {
        resolve(buffer);
      })
      .catch((err) => {
        if (err.toString() === 'Unsupported MIME type: image/gif') {
          let bitmap = new BitmapImage(image.bitmap);
          GifUtil.quantizeDekker(bitmap, 256);
          let newFrame = new GifFrame(bitmap);
          let gifCodec = new GifCodec();
          gifCodec
            .encodeGif([newFrame], {})
            .then((gif) => {
              resolve(gif.buffer);
            })
            .catch((giferror) => {
              reject(giferror);
            });
        } else {
          reject(err);
        }
      });
  });
  return promise;
};