All graphics packages come with pre-set filters that new users like to play with when they first get the package, but then never use again. Let’s face it, if everyone used the default filters, with all images subjected to the same process, it would turn the internet into a dull homogenised whole. Or maybe it already has.
Experienced users tend to shy away from using the default filters present in packages like Photoshop, which can be a missed opportunity, since the processes behind the filters are often quite clever and if manipulated can be a useful tool in any graphic designers arsenal. One case in point is the much maligned Stained Glass filter in Photoshop, which to be fair, isn’t terribly good at creating convincing Stained Glass window images but does do some interesting things you can make use of.
Open any single layer image, preferably one with a good variety of colours, so a photo or complex graphic. Try just applying the filter to the layer using the default settings, so choose Filter, Texture and Stained Glass then just click OK to accept the default settings. You will see your image has been segmented into a number of irregular polygons. Each polygon has a border (this border will be whatever colour your foreground brush is set as) and a flat coloured interior (this colour will be calculated based on the average tone and shade of the pixels on your original image that lay within the polygons border). There will also be some minor shading to the flat colours as Photoshop adds a slightly annoying lighting effect to the centre of any image you use the Stained Glass filter on, it’s fine though, you can turn it off.