Image Processing

Announcements

What’s an image?

Images as functions

What’s a digital image?

Image processing

Noise

Reducing Noise

Mean filtering

Mean filtering

What about border pixels?

Effect of filter size

Weighted average filtering

Gaussian filter

Comparison of mean vs. gaussian filter

Linear shift-invariant filters

Cross correlation

Linear shift-invariant filters

Symmetry in Convolutions

Median filter

Slide 21

Slide 22

Image Scaling

Image sub-sampling

Even worse for synthetic images

Sampling and the Nyquist rate

Subsampling with Gaussian pre-filtering

Some times we want many resolutions

Gaussian pyramid construction

Image resampling

Image resampling

Image resampling

Image resampling

Subsampling with bilinear pre-filtering

Things to take away from this lecture