Thanks for feedback. I'm currently visiting some relatives and can't work with my main computer, i don't know if i can improve the program before weekend... The main function of the program is to find perfect spot for other image to be blended, i understand that once the spot is selected, ... any graphic-guy can do the blending better manually. I couldn't do that myseld ... Before i left yesterday, i took some pictures from my neighborhood and used them as a background with improved place-select/blend algorithm.
I managed to upload some fullscale images to bayimg. There you can see the size of the originals (the ones i used for these first images, are even larger).
// full scale
And TheNut, i indeed use "brute-force" to seek minimum error within the image. However, I use some performance-tricks; the resolution of the image to be hidden determines "size_div", which is used to downscale both images before the first stage. Typically the small-scale is 10-16 times smaller in both resolution components. This small-scale check determines the area of full-resolution scan which fine-tunes the position for the blit.
When i return to home, i'm planning to add rotation to the image. This gives exponentially more good possibilities to the blit.
Thanks for the feedback again