min/max components

The help sections for these components are rather detailed:

Minimum Level
Maximum Level

As for the usage... maybe expert filter makers can give an example of such a filter.

Consider you're going to render a 6000x6000 image.
Consider that you're going to do a simple Hue adjustment and then extract per-channel min/max values.
Consider how much time that would take

The problem is to calculate _one_ sample of the min/max/average color you will need _all_ samples of the input image. When seamless mode is not enabled, it is entirely impossible (since procedural textures in non-seamless mode are practically infinite in all directions). When seamless mode is enabled, it will just take a lot of time (consider blur with radius of 100 percent and unchecked "Gaussian" checkbox as an estimate, subtract around 12-15%). In short -- min/max/avg components might work, but only in a few, limited cases, namely small seamless images with fast components as sources.

jffe,

i've used them a little. i've also used the 'average color' component. it sort of falls into that category as well. i tend to use them when i want a more or less bland color for a background or when i want to set another component's control set to a minimum or maximum range, like a threshold component.

i cant think of an exact filter at the moment, but i'll keep my eyes open.