I added JPEG support :) about jsignature

[beveltd]

how are you actually using this in jsignature?

[PeteW]

I am using this in a phonegap application which captures sugnatures and stores them as 64-bit encoded jpeg values which can be streamed back to the server

[joaopiopedreira]

Hi, I'm trying to use jsignature with that in mind, too (capture signature in Meteorjs app and send it back to SQL Server). How should I go about this? Thanks

[joaopiopedreira]

Finally got this to work using PeteW solution.

Noticed though that the jpeg resulting image had its colors reversed, so I've added the tweek below. Hope it can help somebody :-)

    var exportplugins = {
        'defaultold':function(data){return this.toDataURL()}
        , 'default': function(data){

            // Invert colors
            var imageData = this.getContext("2d").getImageData(0, 0, this.width, this.height);
            var imgData = imageData.data;

            for(var i = 0; i < imgData.length; i += 4) {
                // red
                imgData[i] = 255 - imgData[i];
                // green
                imgData[i + 1] = 255 - imgData[i + 1];
                // blue
                imgData[i + 2] = 255 - imgData[i + 2];
            }

            // overwrite original image
            this.getContext("2d").putImageData(imageData, 0, 0);

            return new JPEGEncoder().encode(
                imageData,
                    10
            );
        }