Peter's Web Site

December 14, 2005

Erhu

The sound of the erhu is the physical manifestation of sorrow. Even when it is upbeat and joyful, there is an unmistakable undertone of muted sadness.

December 07, 2005

Benford's Law

One of the most fascinating thing I've read recently: Benford's Law about the prevalence of the number "1" in real-life statistics.

December 06, 2005

Fixing purple fringing

I read about a neat way to fix purple fringing with Photoshop:

Here's one way of fixing purple fringing:

- if your image has just one later, duplicate it. If it has multiple layers, make a new layer on top, select all, copy merged, and paste into your new top layer

- give it a good gaussian blur (eg 150-200 pixel radius) [or Lens Blur with 50-70 pixel radius --pzw]

- click on the "eye" icon next to that layer to make it invisible for the moment

- go to "select" --> "colour range" and sample some of the purple area with the eyedropper tool.

- go to "select" --> "modify" --> "expand" and expand the selection by a couple of pixels.

- go to "select" --> "feather" and feather the selection by a couple of pixels.

- click on your blurred layer to make it the active layer. Change the layer blending mode to "colour".

- click on the "add layer mask" icon at the bottom of the layers palette. This will apply your changes *only* to the purple areas.

You're done! You can easily modify your changes by painting in the layer mask (in white to get rid of purple, in black to restore purple).

(From the forums at iStockPhoto.com.)