Jimp: Low level manipulation

[sesirimarco]

hi, i use autocrop and i nedd give to the image a border margin.
Any suggestion?

[Iwasawafag]

You would have to create new image of desired size and put result what's left after autocrop() in the middle of it to get extra padding.

Here, I wrote it for you

function autocropWithMargin(image, margin) {
    var backgroundColor = image.bitmap.data.readUInt32BE(0);
    var originalWidth = image.bitmap.width;
    var originalHeight = image.bitmap.height;

    // image = image.clone(); // uncomment this if you don't want original image to be modified
    image.autocrop();

    if (image.bitmap.width === originalWidth && image.bitmap.height === originalHeight) {
        return image;
    }

    var canvas = new Jimp(image.bitmap.width + margin * 2, image.bitmap.height + margin * 2, backgroundColor);

    // clear the area for the image
    canvas.scan(margin, margin, image.bitmap.width, image.bitmap.height, function(x, y, idx) {
        canvas.bitmap.data[idx + 3] = 0;
    });

    canvas.composite(image, margin, margin);
    return canvas;
}

// Usage

Jimp.read('your-image.png', function(err, image) {
    if (err) throw err;

    image = autocropWithMargin(image, 10);
    image.write('cropped-with-margin-or-same-as-original.png');
});

[sesirimarco]

Great, I took a similar manner to solve it.
Thanks!

[Iwasawafag]

You should probably close the issue