Downsampling
From The Glossary of Digital Photography
Using specialized software such as Photoshop to reduce the size of an image. The amount of data in an image is reduced to make the image smaller. This is done by combining data points using various mathematical formulas. The formulas attempt to represent the removed data in such a way that the image appears to be unchanged. Other techniques involve simply throwing away the extra data points.. Currently, using the Bicubic Sharper function in Photoshop seems to be the preferred method of image downsampling.
