Graphics.getPixel(x,y) on ILI9341 Module for ILI9341 LCD CONTROLLER

Some time ago I played around the ILI9341 and added a lot of functions.
GetPixel is done by this, and returns an array with r/g/b values.

getPixel = function(x,y){
    var c,z = 0xff;
    setRect(x,y,x+1,y+1);
    writeCMD(0x2E);
    dc.write(1);
    spi.send(z);
    var zzz = new Uint8Array([0,0,0]);
    c = spi.send(zzz);
    ce.write(1);
    return c;
  }

To read colors of a rect would be very timeconsuming. Translating the RGB-Array to a color used for ILI9341 takes a lot of time. Some lines in assembler speeded it up, but its still slow. I don't have a tutorial for that, could only send sources, if somebody is interested.