Questions tagged [opencv]

OpenCV (Open Source Computer Vision) is a cross-platform library of programming functions for real time computer vision.

Filter by
Sorted by
Tagged with
0
votes
1answer
30 views

Low samples numbers machine vision training for object detection

I'm trying to set-up a machine vision application in which I have to detect the position of a printing nozzle (in the red sqaure in the image) in a field of view in order to prcisely position a ganty ...
1
vote
2answers
43 views

what is the difference between the convolution and differentiation over image in image processing?

In image processing the differentiation and convolution are the terms that are used interchangeably . what is the difference between applying convolution and differentiation over the image ?? How we ...
0
votes
1answer
30 views

Why we have to multiply the images with $(-1)^{x+y}$ to center the transform in frequency domain filtering?

To perform the filtering infrequency domain we perform multiplication of $(-1)^{x+y}$ why??
0
votes
1answer
27 views

How the Grayscale images are converted back to RGB?

In case of RGB to grayscale conversion we take the average of R,G,B channels and convert them to Grayscale which has songle channel. How to convert back the Grayscale to RGB ??
0
votes
0answers
19 views

Use sparse optical tracking to track a Bounding Box object

I need some help on solving this issue. Any tips are appreciated. The goal of the project is to try to track a Bounding Box object, chosen arbitrarily in an image, throughout many frames of a ...
0
votes
0answers
29 views

Calibrating cameras with different resolutions

I have two cameras with very different resolutions. One camera is the RGB camera of the microsoft kinect sensor with a resolution of 1920x1080 and the other one is ...
0
votes
0answers
53 views

How to set the measurement matrix of opencv kalman filter [OpenCV+Python]

I am working on a tracking application where I use the kalman filter to validate my current measurement of the position. I use the code from this question: How to find the probability of Kalman filter ...
0
votes
1answer
17 views

Parameters for inverse image distortion

I'm trying to simulate camera (barrel/radial) distortion, and to reverse it. I.e. a process that would do: Image --> Distorted Image --> ~ Image In ...
1
vote
1answer
37 views

Salt and Pepper impulse Denoising opencv

I am creating a generic method to work on salt and pepper noise and variants. The example images are as shown below : I tried few methods, such as ...
1
vote
0answers
25 views

Finding defects in wall paint (finding difference in textures)

I have been experimenting with computer vision techniques to find defects in paintings, more specifically defective brush strokes. I have tried a handful of techniques such as different filters, One ...
0
votes
0answers
24 views

Finding point height on a cup using OpenCV

Suppose that I want to find the 3D position of a cup with its rotation, with image input like this (this cup can be rotated to point in any direction): Given that I have a bunch of 2D points ...
1
vote
2answers
48 views

How to find position, scale and rotation of a known shape/contour in an image?

I have an image of an object. The image shows a high contrast outline of the object. It is guaranteed that the image shows exactly one object. The shape/contour of that outline is known. It is not ...
0
votes
1answer
56 views

Licence plate enhancement

Is it possible to enhance the image below and make it more readable? I have tried apply binarization but there is some kind of shadow. So I have tried to convert image to gray scale and then ...
1
vote
0answers
10 views

How to find location of minimum dimension of contour using opencv?

suppose this is our input image and now we have to detect the point of minimum dimension, which I show as the red dot in an output image
0
votes
0answers
24 views

Do backgroundSubtractor functions in opencv only detect moving objects?

There are some backgroundsubtractor functions in opencv like backgroundsubtractormog2 , backgroundsubtractorGMG and ... . It seems that these functions only detect moving objects in a video and fixed ...
1
vote
1answer
561 views

Running the BM3D Denoising Algorithm in Python

I am looking for a strong baseline in image denoising and therefore wanted to have the BM3D algorithm in my benchmark. These 2 python implementations: https://github.com/ericmjonas/pybm3d https://...
0
votes
0answers
54 views

Tracking of rotating objects using opencv

I need to track cars on the road from top-view video. My application contain two main parts: Detecting cars on the frame (Tensorflow trained network) Tracking detected cars (opencv trackers) I have ...
1
vote
0answers
16 views

Looking for a way to fill holes in objects, and break bridges between them

I am trying to extract building footprints from satellite images. Using a series of morphological operations i.e erosion and opening by reconstruction, I'm able to obtain the footprints, albeit with a ...
0
votes
0answers
37 views

SIFT between 1 image and dataset (2 images)

I use SIFT, and I want to find the angle of inclination of an image compared to two reference images, in short: I have 3 images : Image x: input image Two images 1 and 2, reference images that are ...
0
votes
0answers
21 views

Calculating a transform with a circle and lines

I am trying to determine the transformation (rotation + translation + scale) between two images in order to shift them. The images are taken with two different modalities that produce very different ...
0
votes
0answers
10 views

Want to create a function that calculates the ISO and Shutter speed based on the brightness of previous image

I want to calculate the shutter speed and ISO of Picamera using the brightness information of the previous image I captured. I have already calculated the brightness of the previous image but I am ...
0
votes
1answer
37 views

How to produce color image using edge detected images?

Hi I am trying to produce an image which is a combination of multiple images such as in focus stacking. Now I have 6 photos and I want to produce a final image such that the final image uses blocks of ...
0
votes
1answer
96 views

Detect valve position without colors

I can't find a solution for my problem and I need your help. I have to create an application to detect if a valve is open or close like this : https://www.youtube.com/watch?v=VY92fqmSdfA Some ...
0
votes
0answers
37 views

Face image quality assessment

I'm trying to filter out bad face images (with artifacts) generated by StyleGAN. Is there a good image quality measurement mechanism in python for doing this? I've tried using BRISQUE but it is not ...
0
votes
1answer
19 views

How do I filter out this horizon from my contour?

I am trying to identify the T-rex and obstacles (cactus and bird) from Google's no-internet game. What I have done is: Apply GaussianBlur filter Apply Canny Apply Dilate Apply erode findContours ...
0
votes
0answers
15 views

Efficient image matching technique for small match library set

Background A scene captured from video frames from an Android mobile device camera are to be analyzed in real-time. The scene will contain up to 12 distinct photos. The library images to be matched ...
0
votes
2answers
22 views

Recommended Order of Performing Denoising, Deblurring and Super Resolution on an Image

In the normal workflow of image processing, there are multiple operations, increase image contrast, image denoising, image deblur and image super-resolution. What are the sequence/order of performing ...
0
votes
1answer
105 views

Finding Homography Matrix Using Lines

I have some Points and Lines from original image and the corresponding points and lines from top view image. -> I tried to find homography using points Used OpenCV function findHomography(...
0
votes
0answers
15 views

center of oblique viewed disk with known radius

I also posted this on the math stackExchange, but it also fits to this forum, so I hope it's fine to post it here as well. I'm working on an issue related to image processing that I simply cannot ...
0
votes
1answer
21 views

Gender classification using Periocular Region [closed]

I have a dataset of the periocular region, I have images of the male and female periocular region but they are only labeled as left and right periocular region, Folder is a mixture of male and female ...
1
vote
0answers
23 views

Size filtering on binary images

I have noisy images from which I extract the contours using OpencCV's findCountours, which performs binarization internally. This results in innumerable small ...
0
votes
2answers
42 views

Camera image pixel structure origin

I am using machine vision for industry task with opencv. I have images from a camera monitoring the process. The detailed look at the small part of the image follows: Enlarged: In the detail, it ...
0
votes
1answer
97 views

How do I detect the sharp edges in the following image?

I am looking to count the sharp pointy triangular things in the image. However I was unable to do so. One approach I did try was take a convex hull of the contour and then find convex defects but it ...
2
votes
1answer
1k views

Outlined text extraction from image using OpenCV

I have some video frames I'd like to extract some text from (for making softsubs from hardsubbed video for learning). The text in question is mostly in Chinese script (some numbers and Latin letters) ...
2
votes
1answer
72 views

What impact have different types of border-handling on high pass or low pass filtering?

When high or low pass filters are being applied to an (grayscale) image, the borders need to be handled separately. They could be filled with 0's or 255's (b/w), repeat the nearest pixel value, or ...
0
votes
0answers
66 views

How can I calculate homography from the room height and camera calibration matrix?

EDIT2: I've added an assumption that the camera calibration matrix is given. Other factors (rotation, camera pose) are still not given. I want to measure actual lengths of floor edges (blue lines in ...
0
votes
1answer
782 views

OpenCV warpPerspective implementation

I've implemented the least squares method to find the homomorphic image to fix the rotation and projection in an image. Now I'm trying to implement the OpenCV warpPerspective method in order to "fix" ...
1
vote
0answers
23 views

KLT tracker, reject tracked occluded points

I want to use KLT tracker for a visual odometry application. Thus, I only want to track object features. Currently I'm using OpenCV's implementation ...
0
votes
0answers
173 views

What are the meanings of Fx, Fy, Sx and Sy in Image Processing?

I am currently reading a book titled "Learning OpenCV 3 Computer Vision in C++ with the OpenCV Library", and I come across these two equations: ...
0
votes
0answers
50 views

Once spines recognized, how do I find each individual book?

I want to make a system like the Book Spine Recognition on Youtube. So I read research paper and I built this system. According this paper, I use Hough transform, then I recognize book boundary ...
1
vote
0answers
56 views

Implementing Edge Preserving Diffusion (Anisotropic Diffusion)

I am trying to implement edge preserving diffusion. Recall the general diffusion equation to be: $$\DeclareMathOperator{\Div}{div}\delta_t u = \Div(g \nabla u)$$ Where $g$ is the speed of the ...
0
votes
0answers
11 views

Adjustments to get better result appyling hough circles

I have the aboveimage and wanted to detect circles spread around the image. I can detect the circles in the middle through hough circles but it does not work out for the left-most circles which exists ...
0
votes
0answers
18 views

How to separate spliced(photoshopped) part from the rest of the spliced image?

I'm working on a project to detect spliced images and want 128x128 patches at the boundaries of the forged regions. I have the authentic background image and the spliced(photoshopped) one. If I ...
1
vote
1answer
203 views

Sum of Squared Intensity Difference for block matching with ORB features, c++

I am trying to implement feature matching algorithm between image reference and image current. The pipeline is as follows: ...
0
votes
1answer
36 views

What principles to use, in order to create field that will be read by OCR?

I currently have an invoice, where some numbers are written by hand, and I would need to read them automatically. My past experience is that people who write numbers will them write in so many ...
0
votes
1answer
524 views

python: how to compute the sharpness features of image

I am extracting the sharpness features of image as shown in the following image mentioned in a paper. I have done with the following code. Firstly, use the open cv convert the RGB to HSL (luminance ...
0
votes
1answer
793 views

python: how to compute the gray level histogram features as mentioned in the paper, and

Hi I am extracting the grey level features of image mentioned in this paper (part 4.5 low level features). "We describe two low level features that are particu- larly important for photo quality ...
1
vote
1answer
1k views

How can I detect pipeline cracks using OpenCV and Python?

I have developed a robot that captures images of the pipeline interior as it moves. The requirement was to be able to detect cracks inside. So far i tried several OpenCV codes that find the crack ...
0
votes
2answers
60 views

Segmenting an image into columns

I want to segment the image below (click for bigger image) into columns based on the natural gaps that exist in the columns. The columns should be perfectly vertical and need not be the same size, but ...
2
votes
1answer
367 views

How to segment multiple overlapping coins (ellipses)

I am doing a program that counts coins (and tells their value by their size) with OpenCV (C++). Let's say we have an image of some coins. If there is an overlap of two coins at the same time, it is ...

1
2 3 4 5
7