Function adjust_contrast

pattern/canvas.js:3125–3129

(pixels, m)

        });
    }
    var adjust_contrast = function(pixels, m) {
        pixels.map(function(p) {
            return [(p[0]-128)*m + 128, (p[1]-128)*m + 128, (p[2]-128)*m + 128, p[3]]; 
        });
    }
    var o = options || {};
    if (o.hue !== undefined)
        adjust_hue(pixels, o.hue);