Changing pixel Values

[tougo]

I know that is to much to ask but i want someone to tell me how can i add values to the pixels of a greyscale Timage
for example the to change the color value of a pixel by 3 (45 before 48 after) something like a brightening effect

excuse me for my bad english

 

[bsisko]

I haven't checked this out yet, but start with the scanline property of the TImage.