how to filter a image in such a way?

hi , guys:

  i have a new question now.

  Suppose that i have a source vgImage drawn with sth and i want to get a destination image in such a way, (image format is four bytes per pixel) : 

if pixel(x,y) in source image != 0X11111100, /* means this pixel contains some color,but no matter what color it is , as long as it is not tranparent white. */
then the pixel(x, y) in destination is set to a specific color.

besides setting the destination image color pixel by pixel in the brutal force way, is there any smart method to deal with this problem. Image Filters part in the openVG manual seemingly contains some useful ways , can you give any tips?