There are three different things going on here. Reduce the number of colors of an image Get the different colors of an image Get the color name Reduce the number of colors There are many techniques to reduce the number of colors. Here you can see how to use color quantization and kmeans. Another approach … Read more
I have been able to work around this problem by iterating over the webcam indexes until reading that camera no longer returns anything: index = 0 arr = [] while True: cap = cv2.VideoCapture(index) if not cap.read()[0]: break else: arr.append(index) cap.release() index += 1 return arr This method returns a list of all indexes that … Read more
I wrote a child class of CvSVM to extract primal form after a linear svm is trained. Positive samples are labeled 1 and negative samples are labeled -1. It is strange that I have to put negative sign in front of alphas and leaving the sign of rho unchanged in order to get correct results … Read more
In general, you can simply compute the threshold using cv::threshold, and then copy the src image on dst using the inverted mask. // Apply cv::threshold on all image thresh = cv::threshold(src, dst, thresh, maxval, type); // Copy original image on inverted mask src.copyTo(dst, ~mask); With THRESH_OTSU, however, you also need to compute the threshold value … Read more
I think you should install opencv-contrib-python instead. The module you’re using is not support in opencv-python. See opencv-contrib-python. To install: pip install opencv-contrib-python
This is my solution for python 3.7 and without using PIL import base64 def readb64(uri): encoded_data = uri.split(‘,’)[1] nparr = np.fromstring(base64.b64decode(encoded_data), np.uint8) img = cv2.imdecode(nparr, cv2.IMREAD_COLOR) return img i hope that this solutions works for all
src is the first argument to cv2.cvtColor. The error you are getting is because it is not the right form. cv2.Umat() is functionally equivalent to np.float32(), so your last line of code should read: gray = cv2.cvtColor(np.float32(imgUMat), cv2.COLOR_RGB2GRAY)
It looks similar to a problem I recently had to separate bacterial colonies growing on agar plates. I performed a distance transform on the thresholded image (in your case you will need to invert it). Then found the peaks of the distance map (by calculating the difference between a the dilated distance map and the … Read more
Wow, that blog post was something special. A whole lot of words to just state that they get the sample buffer bytes that Apple hands you back from a still image. There’s nothing particularly innovative about their approach, and I know a number of camera applications that do this. You can get at the raw … Read more
The earlier answers are good, but they won’t work for non-continuous matrices which arise when you want to serialize regions of interest (among other things). Also, it is unnecessary to serialize elemSize() because this is derived from the type value. Here’s some code that will work regardless of continuity (with includes/namespace) #pragma once #include <boost/archive/text_oarchive.hpp> … Read more