[Patch] Add more image filters

[michael2402]

Currently, there is a quite flexible plugin that adds layer filters:
​http://wiki.openstreetmap.org/wiki/JOSM/Plugins/RasterFilters
Although it is flexible, it has no good usability and is pretty complex for quick use.

We have settings in JOSM to change the gamma value (per layer) and deep down in the settings to change the sharpness.

I want to improve the layer filter dialog (visibility / gamma) and add the sharpness value there. I also wrote a new colorfulness filter.

I made some new icons but feel free to find better ones ;-)

Icons are in images/dialogs/layerlist/

[Don-vip]

In 10142/josm:

fix #12752 - Add more image filters (patch by michael2402, modified)

[aceman]

Hi, what is "colorfulness"? Isn't it any of the other terms on ​https://en.wikipedia.org/wiki/Colorfulness, like chroma, saturation or hue?

[michael2402]

Feel free to find a better name for it. For me, it is simply the filter that makes the image more or less colorful.

The filter computes the grayscale image (lightness).

It then mixes with that grayscale image to reduce the colors or it increases the difference to the grayscale image to increase colorfulness. I did not find a better term for it.

It is a relatively simple mapping between the colors that does not correspond to any HSV value.

red' = (1 - influence) * lightness(red, green, blue) + red

We can name it chroma, but I am no color expert and do not know if that term is really what we want (depends on the exact definition)

[aceman]

I'm also no expert I just never saw the term in any application. But the wiki page seems to know it. I just care that translators get to understand what it means.