Coding question - Align image on the screen

Hello All! I am new to the forum and to C+ so please be gentle with me.

I have open source code that was originally written for a 3.2" tft lcd screen with iphone like buttons on it. I am able to install this code on my Arduino 2650 Mega and see everything on my 7" tft lcd screen but only in the top left corner. The point of using this code was to make sure that everything was written correctly and linked to the correct pins. I want to show my images in the center of the 7" screen but I cant figure out for the life of me the correct coordinates. The code below loads the sample images just fine but in the top left corner (landscape). How do I find out the coordinates of the location that I want to show my images? My screen is a 800 x 480. My Logo image is 378x268 and my Copy image is 149 x 47.

void setup()
  // Setup the LCD
  // init SD card
  // clear the screen

  // boot up logo
  myFiles.loadBitmap(26, 80, 188, 72, "Logo.raw");
  myFiles.loadBitmap(53, 188, 134, 25, "Copy.raw");

Any help would be appreciated.

Figures... I ask for help then all of a sudden I figure it out. For those of you that need help with this, here is the answer.

Parameters: X: x-coordinate of the upper, left corner of the bitmap Y: y-coordinate of the upper, left corner of the bitmap SX: width of the bitmap in pixels SY: height of the bitmap in pixels filename: name of bitmap

Usage: myFiles.loadBitmap(x, y, sx, sy, "imagename.raw");