Binarization

Every image has to be converted to a binary (black & white, or, rather, white and black) before proceeding with Hough space calculations.

To convert an image (usually an edge detection image) to binary choose the EdgeDTC tab and either press the "Otsu Binary" button, for an automatic equalized binarization, or use the manual "Binarize" button, after setting a threshold level between 1-255 for the grayscale or color detection picture.

Note: The "Otsu Binary" choice might fail to work when opening certain 1-bit windows BMP files, giving an all-white picture.. If that's the case, use manual binarization instead.

You can also "Keep an image as is" after loading it in the "Original Tab", by clicking at the "Keep as is" button, if you are sure the image is already binary.

Beware: this program works on white-on-black (that is, WHITE objects on a BLACK background) binary images , so you may want to use the Negative button to correct this, either at loading time or right before starting CHT, GHT or EHT. If you don't, operation will be quite erratic...and potentially very slow :-(

Also: during CHT, GHT or EHT the image in the "Binary" tab must be indeed binary, although the transforms jjust might work, but with potentially erroneous behavior. This is intentionally left in (there is even a "Keep as is" option after loading or edge detection) if you know what you're doing....