This page is designed for anyone seeking help using the PDS Planetary Image Atlas . It is a glossary of terms used in the PDS Planetary Image Atlas, the About MapMaker page, and the related help pages. The color of each pixel is determined by the relative proportion of the red, green, and blue values. In the Viking color data, the green band was synthetically generated from the violet and red spectral image observations of the planet.
Contrast is the visible difference in brightness from the darkest color to the lightest.
PDS Planetary Image Atlas currently uses three Data Sets. Grayscale refers to an image which is composed of shades between black and white. Lines of longitude representing north-south direction on a globe or map. A curve formed by the intersection of a ficticious cutting plane parallel to the equatorial plane. A pixel is an individual picture element of the two dimensional array that forms the digital image.