Answer The resource (image, font, sound, etc.) file path has to be relative to the current working directory. The working directory is possibly different from the directory of the python file. It is not enough to put the files in the same directory or sub directory. You also need to set the working directory. Alternatively, you can create an absolute
Tag: image
To invert colours from black to white in opencv python
I have a condition where I want to detect white line incase of black background and black line incase of white background. I used bitwise_not operation something like this: It is working perfectly until and unless i give a condition like this: I get an error ValueError: The truth value of an array with more than one element is ambiguous.
Is there a fast way to shuffle numpy image in segments?
I want to write a function that can take small images and return a permutation of them, block-wise. Basically I want to turn this: Into this: There was an excellent answer in Is there a function in Python that shuffle data by data blocks? that helped me write a solution. However for ~50,000 28×28 images this takes a long time
How to remove small particle background noise from an image?
I’m trying to remove gradient background noise from the images I have. I’ve tried many ways with cv2 without success. Converting the image to grayscale at first to make it lose some gradients that may help to find the contours. Does anybody know of a way to deal with this kind of background? I even tried taking a sample from
How to detect and find checkboxes in a form using Python OpenCV?
I have several images for which I need to do OMR by detecting checkboxes using computer vision. I’m using findContours to draw contours only on the checkboxes in scanned document. But the algorithm extracts each and every contours of the text. Input Image: Answer Obtain binary image. Load the image, grayscale, Gaussian blur, and Otsu’s threshold to obtain a binary
How to Divide an array in to segments and then do sub segments of the segments using python numpy?
I want to do divide an 8*8 array in to 4 segments(each segment of 4*4 array) as shown below in step2. Then again divide each segment in to other small 4 subsegemnts(each subsegment of 2*2 array) and then find the mean of each subsegment and then find the stabbndard deviation of each segment using the 4 means of the 4
How to rotate an image around its center while its scale is getting larger(in Pygame)
I loaded an image and I want it to rotate around its center, while its scale is getting larger. I know how to rotate an image around its center originally, but it’s hard for me to calculate the position if the scale is getting larger. I tried it, but the image just ‘dances’, not staying in the center. Answer Short
OpenCV: “[ WARN:0] terminating async callback” when attempting to take a picture
I am trying to take a picture from the defualt carmera with python, to do this I am using openCV (import cv2 as cv from python shell). However, when I attempt to disable the camera it closes but with the error [ WARN:0] terminating async callback. This is code I am trying to run: The code outputs the desired result,
Image Type Error: OpenCV Python
I get an image type error when I run my code. I know HoughLinesP requires a grayscale image but when I try to convert the source image to grayscale I get the following error(1): error: (-215) depth == 0 || depth == 2 || depth == 5 in function cv::cvtColor If I run HoughLinesP without converting to grayscale I get
OpenCV Composting 2 images of differing size
I need to alpha-blend 2 images that are not the same size. I’ve managed to get them to composite by resizing to the same size, so I’ve got part of the logic: I’m wondering if I need to make a mask that is the same size as the larger image and then use that with my first image. If so,