I’m trying to find a Python library that works equivalently to MATLAB’s freqz2 for image processing, since scipy.signal.freqz only seems to work for 1-D arrays. Answer Found an amazing library for plotting the 3D surface of the 2-D FFT called plotly. I leave here the lines of code I used to emulate the same behaviour of freqz2 in Python: The
Tag: image-processing
Rotate polygons without cutting edges
I am writing an augmentation code to rotate annotated polygons inside images. I wrote a code but it’s not working right. Just Copy paste the code and you can get the results. Thank you for helping me out. Image: Need to rotate the image as well as a polygon for respective angle. Currently, I am not able to rotate the
numpy.AxisError: axis 2 is out of bounds for array of dimension 0
I’m creating a program the requires a black and white image and two arrays containing the X and Y coordinates of both black and white pixels respectively. I have a program that utilizes OpenCV and binary thresholding to create a black and white image (code source). Hear is the code I have in full so far. The problem I have
Black and white color addition
When red is mixed with green, I get yellow as expected. But when white is mixed with black, I should get normally grey but I get white. Shouldn’t I get grey? Here is the code: Answer I think what @Cris Luengo said (“If you want to get gray, average the white and black pixels together”) is valid; Also I think
How can I report the outcome of the typical spatial frequency Butterworth filter in cycles / degree of visual angle?
I’m working on spatial frequency filtering using code from this site. https://www.djmannion.net/psych_programming/vision/sf_filt/sf_filt.html There is similar code here on stack exchange. What I was wondering though is how to convert the cutoff used in the Butterworth filter, which is a number from 0 to 1, to cycles / degree in the image when I report it. I feel like I’m missing
Filter a numpy ndarray using another numpy ndarray
I have two numpy ndarrays of the same shape (15081, 56724, 3, 3). What I want to do is as follows: Say we have a cross section of the first array, array1[1, 1, :, :], looks like this: I want to convert it to a boolean in a way that the max of each row is True and the rest
Erode x pixels from side of mask with hole in OpenCV
I have a mask which may have holes inside. I want to erode from the outside of the mask (so not the holes), horizontally in, a certain number of pixels. The trick being if I’m eroding inwards 5px and at a certain point there is a hole 3px in from the edge, I want to erode those 3px and then
Merging of Three Images in Single Row And Fourth Image in Next Row Using PIL In Python
I am trying to merge multiple images and as per requirement its working as explained below. I am expecting 3 images should come in one single row and 4th image should come in next row but as per provided output for below image i am getting improper sequence of images i.e. Cat, Dog and Apple should come in one single
opencv align two images by keypoints with stretching
I have two images image1 (object): ]3 Original image without marked keypoints: image2 is a white picture (500×500) In image1 and in image2 I have marked keypoints. I want to align image1 on image2 by keypoints. So the goal that both keypoints overlaps with stretching, scaling and transforming image2. This are my keypoints (csv file). The coordinates are x and
Multi band blending makes seams brighter and more visible
I’m trying to stitch two pre-warped images together seamlessly using multi-band blending. I have two input images (that have already been warped) and one mask. However, when I apply MBB, the area surrounding the seams glow brighter and as a result, they become more visible which is the opposite of the objective here. I have absolutely no idea what I’m