Category "image-processing"

How to determine between inner and outer contour with Python OpenCV?

I want to have a polygon region of interest and would like to perform an object detection algorithm within this area. For example, the user gives some points an

SIFT detection / FLANN matching results in matches with way too long distance

I'm doing some feature detection/pattern matching based on the OpenCV example code shown at https://docs.opencv.org/3.4/d5/dde/tutorial_feature_description.html

Need a python code to find out the Local Binary Pattern and Gabor Filter of all the superpixels individually

I am doing tumor segmentation for my project and have used the SLIC function from scikit- image mark boundaries to create this grid. I am creating a feature vec

Sobel edge implementation issue

For a class I have to implement the sobel edge detector in java, and do I did. But something isnt right, and after 3 hours trying to figure it out I still haven

How to resize(reshape) the images in CNN? Mathematical intuition behind resizing

I have been working on Images for few months for my internship, and recently I have been wondering that is there a mathematical way of resizing the images. This

Alternatives for Error level Analysis (ELA)

I am working on Image processing with deep learning and I came on to the topic Error level Analysis which gives/shows the difference in compression level(I'm tr

convert RGB to black and white

The code snippet in Python should convert the rgb image to black and white, but only a black image output. I do not know where the problem is (input and output

How to connect disjointed lines or edges in images?

I am currently working on lines extraction from a binary image. I initially performed a few image processing steps including threshold segmentation and obtained

can deconvolution wiener filter reduce noise without having blurred image at the first place?

Hi guys greetings am trying to denoise many several noises with several filters for a research i have, i found a deconvolution wiener filter made by "mr.tranlea

Crop a polygon shape from an image without libraries except numpy

I have a list of points let's say 5 points. I want to crop the area that this polygon is covering from the image. Here, red areas are the points and I want to c

How to crop and extract stamp from an image with OpenCV?

I am new to OpenCV. I have a "simple" image of a stamp that I have already processed a bit, as you can see in the code below. Now I have the problem of cropping

How to desaturate the background of an image in Python

I need to desaturate the background of this kind of images. I thought I can find the largest contour and desaturate everything around. So far I can find the lar

Texture transformation

I am working on eigen transformation - texture to detect object from an image. This work was published in ACCV 2006 page number 71. Full pdf is available on cha

What do the h31 and h32 terms in a homography matrix mean?

I have used the MOTION_HOMOGRAPHY function in OpenCV (python3.6) to register a pair of images, and I am trying to interpret the 3 x 3 warp matrix the function r

transforming img to gray error, tuple out of range

I am using this function that I found on the web, its add_speckle() function for adding speckle noise to images : def add_speckle(k,theta,img): gauss = np.

Use cv2.findContours output as plt.contour input

I have the following image I find the contour using contours, hierarchy = cv2.findContours(thresh, cv2.RETR_LIST, cv2.CHAIN_APPROX_NONE) contour = contours[0]

2D Ball Stabilization Platform

I am trying to do 2D ball stabilization platform which always keeps the ball which is put on the platform, center of the platform (x= 0, y=0). Here is my restri

Use OpenCV to identiy hollow and filled circles

I'm using OpenCV houghcircles to identify all the circles (both hollow and filled). Follow is my code: import numpy as np import cv2 img = cv2.imread('images/3

Python/Opencv save multiple images to folder with different names

I am working on image processing, I have a folder with all of the images that needs to be processed, and I want to save all the processed images to another fold

Why the injected wavenumber can't match with the 2-D plot?

I want to inject a 2D travelling wave into a sensor system for seismic data analysis. To do this, I inject a 2D sine wave of known parameters (wave numbers (lam