RGB Spectrum Quadra User's Guide - Manual (Page 91)

I M A G E C O N C E P T S
Image Rectangles
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I M A G E R E C T A N GL E S
The resolution of raster scanned images is defined by the number of pixels per
line and the total number of lines per frame. For example, the XGA format is
defined as having a resolution 1024 x 768 (1024 pixels per line and 768 active
lines). This convention is applied to both the input and output of Quadra.
Within the Quadra architecture, the input signal is the source image. The
portion of the input signal that will be used (and manipulated) is known as the
source rectangle. This is an important point — it means that the source
rectangle does not necessarily have the same dimensions as the input signal.
The destination rectangle defines the size and position of the image as
displayed on the output.
Each type of rectangle is described below:
• A “ source rectangle” selects a rectangular portion of a full size input
image. Typically, the source rectangle contains the entire image, but it
can also contain a cropped portion (or subset) of the entire picture.
This portion fills the destination rectangle (as described below) on the
display device. Quadra automatically changes an input’s source
rectangle as various zoom and pan functions are used to manipulate
portions of the full-size image.
Refer to the “ Source Rectangle ” section for more information.
• A “ destination rectangle” specifies the output image’s size and
position on your display device — as defined by the source rectangle’s
parameters.
Refer to the “ Destination Rectangle ” section for more information.
Source and destination rectangle settings are accomplished using the WSR
(Window Source Rectangle) and WDR (Window Destination Rectangle)
commands, as discussed in the following sections.