An image's root space is a left-handed coordinate system that is perfectly aligned with the pixels of an acquired image prior to any image processing. The origin (0, 0) of the root space is typically at the upper-left corner of the upper-left pixel of the image. The positive x-axis extends to the right while the positive y-axis extends down.
The following figure shows an image with its root space overlaid in red.
In an acquired image, the root space coordinate grid defines the boundary between image pixels. The location of any feature can be described with (X, Y) values from the grid.
As an acquired image undergoes image processing operations (subsampling, morphology) that change the total number of pixels in the image, VisionPro automatically re-adjusts the root space such that features in the processed image have the same root space coordinate locations.
The following figure shows the same image after it has been reduced in size through subsampling.
After image processing, the root space coordinate grid no longer corresponds to pixel boundaries. VisionPro automatically adjusts the root space so that image features (such as the "C" in "COGNEX") retain the same coordinate locations.