This app generates simple repeating units for textures. It blends pixels from both sides of the image & top and bottom so that the image is seamlessly stitched together. It’s a pretty basic approach and a better method would be to use wavelets or to assist the user in making the unit cell themselves. I really should update it sometime!
If the app appears not to work make sure you are following the correct order of operation. That is 1) load image 2) generate texture image 3) use texture image to create repeating pattern. The buttons are marked in order.