I guess the reason could also be, that there is some kind of check if the image is empty. In the attached image, all pixel values are black, the information is in the alpha channel.
Consider the PDF file attached. It contains the same image, but I added a tiny red dot on one pixel on the top right area. The error message does not show up, despite normal deflate compression.
I guess the reason could also be, that there is some kind of check if the image is empty. In the attached image, all pixel values are black, the information is in the alpha channel.
Consider the PDF file attached. It contains the same image, but I added a tiny red dot on one pixel on the top right area. The error message does not show up, despite normal deflate compression.