Emphasis

This is quite a complicated filter to get to grips with, but it's worth the effort - it can give some very useful effects. The filter allows you to select up to eight colours, then either emphasise or de-emphasise them in the image. Colours that are de-emphasised are converted toward grey, on a sliding scale that depends upon how close they are to one of the colurs that you've selected. That may sound obscure, but a little experimentation should make everything clear.

	The effect is easiest to use on an image that has simple, bold colours like this one - Lee, canoeing with friends.
	Click on one of the colour selector buttons to bring up the host program's colour picker, then either select a colour from there, or from the image itself if your host allows it (eg PaintShop Pro does, but PhotoImpact doesn't. There are ways around this - see below). The 'Aggression' and 'Tolerance' sliders control the effectiveness with with the filter matches the colours you select to those in the image - play with both to get a feel for how they work. The 'Tint' slider introduces a tint in the current background colour to those areas that are being converted towards grey.
	This is the result with the settings shown above, and the mode set to 'Emphasise'. The colours I picked were from the instructor's mauve canoe and the red helmets. Note that if you select a colour, then decide you'd rather leave it out, you can do so by clicking the colour selector button again and setting it back to black. You can also click the 'Reset' button to reset all selectors back to black.
	For the record, this is the effect with the same colour selections but the mode set to 'De-emphasise'. Now the yellows have survived, but the mauves and reds have been shifted toward grey.
	You may have noticed the 'Scan' button; click this, and the filter will automatically scan the image and set the colour-selectors to the eight most dominant colours. This is particularly useful in those hosts, such as PhotoImpact, which don't allow eye-dropper selection from the image while the filter is open. The method used isn't perfect - a red object, for example, will often dominate an image to the eye, even though it occupies only a small part of the frame. The filter, however, won't notice it, so the colours it selects for you won't necessarily be quite what you would have liked. Still, on this image of a horse...
	... we get a reasonable result. Personally, I like this filter a lot, and will continue to develop the idea, so check back in a few months' time if it appeals to you too.