Transparent Overlay Blocky Edges


  • Hello

    Every time I use a transparent overlay I am left with a mostly transparent image but there are always some black blocky pixels hanging around that just won't leave.

    How do I get a transparent overlay that is 100% transparent around my image without any black blocky remnants?

    Thank you so much in advance. =-)

    • Edited by Jamie Kins Monday, March 27, 2017 4:07 PM Fixed Typos
    Monday, March 27, 2017 3:59 PM

All replies

  • Hi Jamie,

    This depends on the nature of the blended (overlay) image and the technique you use to blend the 2 images. If the image has what appears to be a pure background (such as fully white), but it's saved using lossy compression like JPEG, compression artifacts could cause the white areas at any edge to become non-pure white, such as shades of light gray. If you use a mixing technique that relies on the background being a pure color, these edge areas could come out as 'blocky' pixels.

    Another possibility for such pixels arises if you use a transparency mask like an Alpha channel. If the mask has abrupt jumps from transparent to opaque, the blended pixels at these jumps could be a bit noisy. One way to fix that is to smooth the blending mask. This is explained in this forum post I made on my company's forums:

    If neither of these ideas explain what causes your problem, post more information about how you're mixing the overlay with the main image, and if possible attach both images or post a link to download them.

    • Edited by Amin Dodin Thursday, April 20, 2017 11:18 PM
    Thursday, April 20, 2017 11:12 PM