Vovsoft Alpha Blend 2.1 | File Size: 19 MB Merge two images with transparency. Alpha blending (alpha compositing) is the process of combining an image with a background image to create the appearance of partial or full transparency. It is often useful to render image elements in separate passes, and then combine the resulting multiple 2D images into a single, final image called the composite. Vov Alpha Blend applies this process to two images and generates a new image file.