Images are very often composed of pixels. Pixel stands for "picture element". In 3-D, a pixel is sometimes also called a voxel, which stands for "volume element".
To analyse images it is very important to know how to examine the pixels (voxels) in an image.
concept_map:>
graph TD
Im("Image") -->|has many| P("Pixel")
P -->|has| V("Value")
P -->|has| I("Indices")
P -->|aka| V("Voxel")
P -->|can have| S("Size")
figure:/figures/pixels.png
figure_legend:
activity_preface:>
Explore the values, indices (and sizes) of pixels in an image.