This tool helps you to familiarize yourself with Hough space - the result of the Hough Transform: Filter / Hough Transform. Click on the image, or on the Hough transform, and see the corresponding line or curve in the other image.
|Orig Im||Select Original Image.|
|Hough xfm||Select Hough transform image.|
|Line color!||Lines and sinusoids are drawn in this color. Click to change to the menu selected color:|
|Hough Click||If ON, click and drag on Hough Xfm, see corresponding line on Original image. Draws line with line color on mouse up.|
|Orig Click||If ON, click and drag on Original image, see sinusoid on Hough Xfm image. Draws sinusoid with line color on mouse up.|
|Square Gratings||Types line spacings in each direction and the angle between them. See example.|
|Spot R!||Vertical halfwidth of spot. (Approximate - this sets the region for the measurements.)|
|Min Pct!||Estimate of minimum distance between spots.|
The Linear Hough Transform is often represented this way:
where r (rho) and theta are the distance and inclination of a line in the image (below, left). Thus, in Hough space (below, right), the line corresponds to a single point.
The Linear Hough Transform maps straight lines into points. Points are easier to locate (to blob) than are lines, using image processing techniques.