Question

I have a background picture (lets call it B), i want to put an other image (a red dot gif or png) over B, in a specific coordinate of B.

For example, if B is 600x600px and Xcoor is 300 and Ycoor is 300, when the user load the php sript, B will be showed with a red dot in the center. Thanks for any help.

Answer 1

You can make use of a image library that provides such a functionality with ease, for example WideImage which is based on PHP’s GD2 library.

An example of merge with opacity 30 to position 10, 10:

  $img = WideImage::load('pic.jpg');
  $watermark = WideImage::load('logo.jpg');
  $new = $img->merge($watermark, 10, 10, 30);
  $new->output('jpg', 90); // send to browser

See Merge/Watermark and Output to browser Example.

To center the watermark on the picture, you can make use of Smart coordinates. Assuming the red-dot image is 60×60 pixels and it should be put in the middle of the image:

 $new = $img->merge($watermark, '50% – 30', '50% – 30');