Questions tagged [image-processing]

13921 questions
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Binary Segmentation of an complex image in python. [closed]

I was trying to implement a binary segementation for my project work but I got stucked with the binary segmentation code. I just want to a get a continuos segmentation of a player and background in the picture like this image (A proper segmentation of a hand). imgort numpy as np impo...
kanik garg
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How to pair screenshots with videos?

I have folder with short videos and folder with images. Most of the images are sceenshots from one of the videos, but they may not be exactly the same (different size, noise, loss of details because of compression, etc). My goal is to match every image with video it was taken from. So far, I use Ope...
velblúd
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Edge based binarization

I am trying to implement the edge based binarization algorithm that was written in the research paper 'Automatic License Plate Recognition Using Deep Learning Technique' but i as i implemented it i get the final image all black and can not find the problem. import cv2 import numpy as np def edge_bas...
Ibrahim Sherif Yahia
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Method to separate dotted numbers from an image

I'm going to do a specialized OCR system which recognizes the above dotted numbers. (The sample picture may not contain all special cases - see below. ) We decided to separate the number string and recognize each digit before we put them altogether to form a final result. The question is: How to cle...
Aurus Huang
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Sobel edge detector in R?

I am working on an R assignment about Sobel edge-detection. Unfortunately the video tutorial I was following uses R for every other task, but switches to python for image processing - I am guessing he did not find any useful R package for image convolution type work (this tutorial is from last year)...
Manojit
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What's the best idea to remove defferent backgrounds from images?

I want to convert this photo: to this one: And this photo: to this: And son on. I thought I can use color threshold but what if there are some pictures or content inside the photo? because I don't like to damage them and only want to remove the background. So, as I am new in OpenCV and Image process...
Hasani
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Implementing a License plate detection algorithm

To improve my knowledge of imaging and get some experience working with the topics, I decided to create a license plate recognition algorithm on the Android platform. The first step is detection, for which I decided to implement a recent paper titled 'A Robust and Efficient Approach to License Plat...
Gooey
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Evaluating a double integral in Matlab with Dirac Delta function

For an image processing project I need to calculate the following Integral in Matlab. delta is the dirac delta function. But the Problem is when I calculate some samples the output is always 0. My matlab code is as follows: fun = @(x,y) dirac(0 - (x * cosd(135) + y * sind(135))); q = integral2(fun,...
Olli Ver
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Custom Imagenet Dataset

I want to make my own custom dataset of imagenet taking 20 classes out of 1000. I am able to convert it to TFRecords format but I want a keras friendly version for it as keras is more flexible for me.
Ayush Agarwal
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image processing : Segregating panel vs house like structure

I am working on a problem that involves segregating solar panel vs house. Both the house as well as panel are of same color. NOTE: There are two houses in the image. I am referring to the one which is bluish. PFB the image as well as my approach. Any insights how to deal with such situations are wel...
vijju
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Drawing a histogram in opencv python

I want to detect lane departures of vehicles by processing front camera video.For that I want to select one pixel line of each frame horizontally and analyze how those pixels colors change. For that I want to draw histograms for R,G,B channels which has pixel number from left to right in x axis and...
SSR
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Tensorflow Error:ValueError: Shapes (?,) and (656, 875, 3) are not compatible

import tensorflow as tf reader = tf.TFRecordReader() filename_queue = tf.train.string_input_producer(['output/output.tfrecords']) _,serialized_example = reader.read(filename_queue) features = tf.parse_single_example(serialized_example, features={ 'image_raw':tf.FixedLenFeature([], tf.string), 'heig...
liyu
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How to automatically find the threshold and sigma values for Canny Edge Detection?

I want to find the range of threshold values used and sigma values used for specific images. For example, If there is a set of images of different types such as too bright and high contrast, too bright and low contrast, not bright and high contrast, How can I know what range of threshold values and...
Image Check
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i have trained MNIST with accuracy 99.2% but with wrong predictions

I have been using this program to predict my handwritten images to predict a number using previously trained data. The following is the program. please help me out.im new to this This code is used for image processing: import numpy as np import matplotlib.image as mpimg img=mpimg.imread(/images.png...
john joy
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Image processing : Extract background class from annotated images

Given an image of dimensions aXb (see an example below), and a few rectangular annotations for different classes, what is the most effective (or non-brute-force) method for finding non-overlapping rectangular annotations (at least m X n dimension) not covered by the the already provided annotations?...
GKS
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How to automatically save the output image file in a specified folder?

I am using Canny edge detection on images. Since my original 10 images are in the path folder, C:\Users\X\Desktop\FoodRGB as 01.jpg, 02.jpg, 03.jpg and so on, I want to save all my output images in the folder C:\Users\X\Desktop\FoodCanny as 01.jpg, 02.jpg, 03.jpg. I figured that I have to use imwrit...
Image Check
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Can't get HQ favicon for my blog

I have some HQ images that I'd like to use one of them as my favicon, and I've turned them into icons using this online converter: https://realfavicongenerator.net/ But the result is too blurry no matter what output I tried. I read somewhere that Blogger turns uploaded images for favicons into 16x16...
salam2009
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Fastest way to call two functions multiple times without using a list of input parameters

I have written a small programm that uses a pipe. The parent takes care of camera connection while the child is processing the images. The child process calls two functions FunctionA and FunctionB. Both times the image from the parent is processed. I want to run the two functions as fast as possib...
Max Krappmann
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how to properly use 1x1px transparent image

I've seen many websites, usually ones with large amounts of images or large resolutions, use this technique. My question is, how do use it properly? From the articles I've read on here as on other forums and blogs here is my base code: Is this how it is suppose to be set up?
user1377298
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C# Get pixel location from Image<,> EMGU CV 3.3

I've been working on an EMGU based project where i need to create a skeleton image with the ZhangSuen thinning algorithm, which works perfectly fine. For further analysis I want to obtain all pixel locations of the skeleton and store them in a List I've researched a lot about performance issues when...
Kajij
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color deconvolution: use custom stain matrix from Image-J with scikit-image

I want to use scikit-image 'stain_separation' method with a custom stain matrix. I have used the color deconvolution plugin from Image-J to create a custom matrix. When I use these values, the stain separation does not work at all (all channels look the same after devonvolution. When looking at bui...
Mario Kreutzfeldt
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Most efficient way to track multiple small objects in MATLAB?

I am relatively new to image processing, and have never attempted to do anything with images in MATLAB, so forgive me if i am making some very rookie errors. I am attempting to make a program that will track ants in a video. The video is taken from a stationary camera, and records the ants from a bi...
Dan Hope
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Metal shader output data (GPGPU)

I'm trying to implement some image detection algorithms on ios and I need some data preparation that should work as shader (Metal) so it should pass output array with result data. Small example: SWIFT ... // Create buffer var resultBuffer = device.makeBuffer(length: SIZE * MemoryLayout.size, option...
Sergey Grigorchuk
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Obj and No Obj fields in YOLOv2 darknet always 0

I am training YOLOv2 model on custom data. It has 6 classes of data. I follow AlexyAB's darknet to train for custom training. The dataset I am using is COQE dataset mentioned in this paper. The problem I am facing is whenever I start training the Obj and No-Obj attribute goes to zero. In the cfg fil...
Perseus14
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Can the input of the blockproc function in matlab be variable based on the evaluated block?

I just want to know if it is possible to pass a variable input to the blockproc funtion. For example: fun = @(block_struct) my_fun(block_struct.data, x); out = blockproc(im, [N N], fun); I would that the input x changes for each block. In particular x should be equal to the number of the block, e.g....
Alessandro
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How does parameters impact on rectification process?

Why does rectification work like this? Please can someone explain me it in details? How does extrinsic parameter affect rectification result? 1) I build the set of stereo cameras where I can rotate them as I want to. My input images: 2) I calibrated them using Matlab and confirmed by Kalibr method....
MichalSzczep
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Can't passing Mat object in Opencv jni android studio

I'm working on my project which is about Document Shadow removal in android application. I try to modify the c++ algorithm to android by using button to process the input image to remove a shadow but There still some error and I have no ideal how to solve because I'm not good at coding here is the c...
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Adaptive Canny Edge Detection Algorithm

I am trying to implement Canny Algorithm using python from scratch. I am following the steps Bilateral Filtering the image Gradient calculation using First Derivative of Gaussian oriented in 4 different directions def deroGauss(w=5,s=1,angle=0): wlim = (w-1)/2 y,x = np.meshgrid(np.arange(-wlim,wlim...
Siladittya
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Apply object mask to LBP calculation

I see lots of articles applying lbp for texture based image classification. I just wonder three things about this technique that I couldn't find clear answers from Google: How the algorithm calculates lbp for border pixels of an image that don't have enough neighbor pixels around them. If we have e...
Son Vo
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How to make a sobel filter and apply partial derivatives and magnitude to an image

I'm currently trying to implement sobel filter in python, in the code below i attempted to as wikipedia explained how sobel filter worked, hoever i haven't understood what the magnitude does to the image, and how to apply it G_x = np.array([[1,0,-1], [2,0,-2], [1,0,-1]]) //Gx G_y = np.array([[1,2,1]...
danjo
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Fill in boundries detected using Canny

I am a beginner in digital image processing and i have a CT lung image that i have detected each lung outer boundary using Canny. Now i just want to 'fill' in the boundaries with ones so that i have the mask matrix for the lungs for further processing inside them. I am trying to use a for loop but...
Ahmed Mohamed
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Changing contrast of image with alpha channel causes yellow tint

I am trying to adjust the contrast of a BufferedImage using RescaleOp. Changing the contrast of an image without alpha channel works fine, but for images with an alpha channel it creates a yellow tint; what am I doing wrong? To verify that the issue arises because of the alpha channel I loaded the o...
domisum
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Convolving an image with a mask displays an all white image

Very new to MatLab, just figuring some things out and had a question. I am basically trying to filter/blur an image using conv2() but I am getting an all white image when I am using imshow() I am reading the image in with testImage = imread('test.bmp'); This is a uint8 image of a grayscale. I am try...
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Variational Autoencoder loss is increasing

This is my particular code for creating an abnormal convolutional autoencoder and my problem is the loss function is not able to converge to anything at all. I have tried different optimizers for computing the loss. is there anything that i am doing fundamentally wrong with my AutoEncoder? import ke...
BlackSpecter
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CvInvoke.Canny() - gives different results on different computers

when trying to perform some binary manipulations on the exact same image file, but on different computers (&monitors), i get a different result when using the CvInvoke.Canny() method. before calling this method, i use several manipulating methods such as: CvInvoke.Threshold() , CvInvoke.Erode() , Cv...
RedHat
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Using Earth's Mover Distance with Emgu CV

I am working on a project in which I try to compare two images in C#. I'm using EmguCV (a C# wrapper for OpenCV). I've tested some funcitons which work (compareHist for example). I am now trying to use the implementation of Earth's Mover Distance. As I use color images, I build a 2d Histogram based...
Dadedidododu
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different ways to convert RGB2GRAY

I had a job interview recently about image processing stuff, in that interview they had a question about convert RGB space to Gray Space(it's an easy question in first thought) so I answered: we can performed this task by using below equation: Gray = 0.299 * R + 0.578 * G + 0.114 * B but one of them...
saeed masoomi
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Image recognition for Payment bills

I want to extract useful information from images of the bills. I have already converted images to text using OCR + pytesseract and extracting the information based on specific words like total, amount, etc. What will be the best generic approach for handling various types of unstructured bills to ex...
Sourabh Potnis
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C++ Write large array as CSV to disk

I'm trying to write out an image from a camera to disk. To keep it simple for post processing down stream, we chose to use a CSV format (Other systems we have use this format as opposed to binary). The issue is to write a 1MB image it takes ~1 Second. I'm looking to speed this up by at-least 10x. Id...
MadHatter
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How to choose training data from a satellite imagery for supervised classification?

I am performing supervised classification of Sentinel 2 imagery using a Random Forest Classifier. I wish to select the training data from the image. Could anyone please tell me the method to efficiently perform this?
Shivam Pande

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