Follow me. We need only several steps to achieve unique effect of a triangle mosaic.
Download PSD file
Step 1, Open up a picture and leave certain spaces in all sides. You will know why doing that later. Copy two new layers;
Step 2, Free transform the two layers respectively; see parameters in the picture;
Step 3, Add a same mosaic on the two layers;
Step 4, Return the picture to its original proportion, and see parameters in the picture;
Step 5, Change the mixed model on the two layer to lighten model.
Step 6, Deal with the above two layers with “filter – sharpen – sharpen edges”, then adjust as you like all layers as “brightness/contrast”. Please see the effect after overlaying in the follow.
Anyone is welcomed to redistribute and quote the content only if he or she notes its origin. http://4-designer.com/2013/07/the-procedure-for-producing-a-triangle-mosaic