User Guide

Glossary
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PDF
An acronym for Portable Document Format. You can view PDFs on any computer using the free
Adobe Reader software.
Perceptual
Rendering intent that scales all of the colors within one gamut to fit within another gamut. Best
used for photographic images, as it maintains the relationship between the colors more
accurately than the colors themselves.
perspective distortion
Perspective distortion is caused by wide angle and telephoto lenses, which distort the
perspective of large or far-away objects. For example, if you take a photo of a tall building, the
building may appear to be narrower at the top even though the building is the same width from
top to bottom.
photo album
See album.
photo editor
See image editor.
picture viewer
See image viewer.
pincushion distortion
In pincushion distortion the photo appears to shrink inwards toward the center.
pixel (PICture ELement)
Smallest visible portion of a digital image, arranged in rows and columns.
plug-in
Software module that adds functionality to a larger program.
PPI (pixels per inch)
Measurement of how an image is displayed. More pixels per inch result in higher image quality.
primary colors
Colors that can produce other colors when blended. For example, in the RGB color model, red,
green, and blue are primary colors.
R
raster image
Image composed of a rectangular grid of pixels. Each pixel contains a defined value about its
color, size, and location in the image. As a result, resizing the image can affect its quality.
rating
Assign ratings (1, 2, 3, 4, 5) to photos to help sort and manage them more easily.