Thursday, October 11, 2007
Noise And Grain
Don't know if this is of any use to anyone but this morning was printing a picture and noted that in darkening the sky, the noise in the digital image increased (it was a shot on a 10D). I experimented with ways to reduce the noise and settled on gaussian blur 8 pixels wide (which is a huge amount of blur), applied to a duplicate layer, black masked then painted into in varying amounts considerably less than 100% - at 100% screen size there was noticeable blurring of cloud edges but in the print the grain nicely disappeared.
The advantage over using something like noise ninja was I was able to apply it to the exact degree and precise place I wanted it. Using a smaller radius for the blur just made the noise uglier without hiding it.
Here's examples of before and after. Click on the images for true 100% inspection.