10 Replies Latest reply on Aug 16, 2012 4:28 PM by conroy

    Bicubic scaling layer mask leaves 1-pixel border

    fennworld Level 1

      When resizing a layer with a layer mask and using any bicubic method, the layer maks scales 1 pixel differently from the other layers. Is this normal due to some component of bicubic interpolation or is it a bug?

       

      Try the following:

      Create a new image in Photoshop at 800 px x 800 px

      Leave the locked BG layer and create a new layer

      Fill the new layer with green (or your favorite color)

      Add a layer mask to the green layer and fill the mask with black (via Fill with foreground color or Alt+Del) to completely remove any visible green from your document

      Now use Image-> Image Size (Opt+Cmd+I) to resize your document using any bicubic scaling method. Resize to 600 px by 600 px.

       

      Now zoom in on the document's edge at the pixel level. Is it completely white as it should be?

      In my case, no. However, if I use 'nearest neighbor' interpolation method when scaling, I do get a solid white edge. Even more strange, if I fill the layer mask with black by inverting it rather than filling it the problem does not happen.

       

      Any ideas?