Sometimes when using the “Repeat X” and "Repeat Y "of the image layer, the edges of the two images are misaligned. It can be solved if Tiled can allow users to use the mirrored image when repeating the image (similar to GL_MIRRORED_REPEAT in OpenGL).
Also, is there a way to scale the image that is shown in the image layer?
+1 for this sort of mirroring. Though uncommon compared to plain repeating, it’s far from an unknown technique in games, and one should not have to duplicate the pixel data to use/preview it in Tiled.
Scaling is not supported, and Bjorn has resisted adding it as he sees that as more appropriate for Tile Objects than Image Layers. Scaling for Image Layers has been requested on GitHub: #1306, #3114. A big challenge with adding scaling is the UI, but I’d be happy with a scale factor number input.