gistfile1.js

function CroppedImage(image,sx,sy,sw,sh){
    this.image = image;
    this.sx = sx;
    this.sy = sy;
    this.sw = sw;
    this.sh = sh;
}

CroppedImage.prototype.draw = function(context,x,y){
    context.drawImage(this.image, this.sx, this.sy, this.sw, this.sh, x, y, this.sw, this.sh)
}


//Usage:

var sprite1 = new CroppedImage(img1, 0, 0, 25, 25);
var sprite2 = new CroppedImage(img1, 0, 25, 25, 25);

sprite1.draw(context, 0, 0);
sprite2.draw(context, 34, 62);