如何将OpenCV中的adaptiveThreshold用于大于255的值（即，类型CV_8UC1）？

Question

I want to use the adaptiveThreshold function from OpenCV in order to determine appropriate, local thresholds for values in a vector<double> .

adaptiveThreshold is specified in the docs as follows:

void adaptiveThreshold(InputArray src, OutputArray dst, double maxValue, int adaptiveMethod, int thresholdType, int blockSize, double C)

Note that src has to be a Source 8-bit single-channel image (so the input needs to be of type CV_8UC1 if I understand correctly, please correct me if I'm wrong here...).

Since my vector<double> is not of type CV_8UC1 , one way to approach this would be to normalize the values within a range of 0 and 255 and then feed the resulting normalized values as a vector<unsigned char> into the adaptiveThreshold function.

This might look good at first sight, but it comes with a large loss of precision as the values within my original vector<double> grow very large and get normalized down to the range of 0 to 255 .

So, I am wondering if there isn't an option to use the adaptiveThreshold function for a wider range of values. It seems so unlogical to me that it should only work with values with a max of 255 ... It feels like I oversee something quite simple but I can't figure out how to solve the issue...

Answer 1

I'm afraid there isn't such an option for a wider range of values. But it is fairly easy to derive a version that takes 'double' values as OpenCV is open source. Just find the source code of adaptiveThreshold() and change it for your own use.