Image Processing Reference
2.8.3 Simulating Film Grain - Covering
Up Blemishes with Noise and Pixels
Covering Up Blemishes
For this exercise, we will use the picture from Miami again. We saved it as
a JPEG for the Web. What if we compressed it too much and therefore got
compression artifacts? What other methods are there to edit images with
obvious damage such as compression artifacts? For example, suppose you
have an old and highly compressed image from a website. The Selective
Gaussian Blur filter can help, but let us look at further options.
Covering Up Blemishes with Noise
Open compressionartifacts.jpg from the SampleImages folder on the DVD.
Enlarge the image by 200% so you can make out the compression artifacts.
The HSV Noise
filter window. In the
image window, you
can see the result of
applying the filter.