Combine/Fuse/Mix images

Combine/Fuse/Mix images together with user defined weighting/opacity.

This is a small function designed to fuse/blend images together. We have found it to be handy in several cases- both for images and videos (see Example III for videos fusion).
It can be used for comparing several image processing methods, applied to an image. While image processing algorithms are frequently evaluated by comparing resulting images side by side, via concatenation or subplot it results in large images. The proposed function allows presenting several methods, each applied to a user defined region of the image, so several methods are evaluated on a single image. This is expected to be even better for videos, where camera motion will result in scene migrations between areas. We have found this function to be useful in generation of test images for segmentation algorithms evaluation. Several texture images were combined in a mosaic, subject to further segmentation. This function can be used for combinations of different images, though we believe imagesMixture to be a more appropriate function for this task. While having only a few inputs parameters, the function allows the user to control the region of each image, and the inter-image opacities, so both soft and sharp margins are possible.