Morphological filters can also be used to detect specific features in an image. In this recipe, we will learn how to detect contours and corners in a gray-level image.
The edges of an image can be detected by using the appropriate filter of the cv::morphologyEx function. Refer to the following code:
// Get the gradient image using a 3x3 structuring element
cv::Mat result;
cv::morphologyEx(image,result,
cv::MORPH_GRADIENT,cv::Mat());
// Apply threshold to obtain a binary image
int threshold= 40;
cv::threshold(result, result,
threshold, 255, cv::THRESH_BINARY);The following image is obtained as the result:
In order to detect corners using morphology, we now define a class named MorphoFeatures as follows:
class MorphoFeatures {
private:
// threshold to produce binary image
int threshold;
// structuring...