A mosaic can be created tile by tile, or from an existing image. A computer image is made of pixels of different colors. In the same way, a mosaic is made of tiles of different colors. However mosaics have a lower resolution (spatial resolution or number of colors) than most of the existing computer images. In order to diminish these two kinds of resolutions, image processing functions are available. The Fusion processing diminish the spatial resolution of an image by making a correspondence between a group of pixels of the image and a tile of the mosaic. In a computer image, pixels may have a lot of colors, but the tiles for a given manufacturer have a palette from 20 to 50 colors. The color reduction processing diminish the number of colors of the image. Another function of the software is the drawing tile by tile of a mosaic. Half-stone tiles (or triangle) and rectangles can be created. A mosaic of a text can be realized easily. Non rectangular mosaics (like mirrors or grounds) can be constructed.