File:Hall2006 Sampling example.png

Summary
Resolution and localization in digital photography. (a) Sharp image at full resolution, 512 × 512 pixels, shown here at about 340 dpi. Very small-scale features are resolved. (b) The same image with a 25 × 25 pixel Gaussian smoothing filter applied. (c) The same image downsampled by a 10 × 10 pixel filter, to 51 × 51 pixels, or 34 dpi at this scale. (d) The Gaussian-filtered image in (b) after downsampling every 10th pixel. Sampling the smoothed image is not as detrimental as sampling the sharp image.