All Questions
269 questions
2
votes
1
answer
163
views
Feature selection of Gabor filter
I am working with Gabor filter with level set method as in A Level-Set and Gabor-based Active Contour Algorithm for Segmenting Textured Images. As you known, Gabor filter gave many filter output. Some ...
CommunityBot
- 1
2
votes
1
answer
304
views
Image Segmentation based on coordinates from reference points
I have a set of colors in a card, as below (I can modify the card as required)
I have 4 reference points at four corners. I have a bunch of colors at known coordinates (in mm) from these reference ...
CommunityBot
- 1
3
votes
1
answer
127
views
Implementation of Normalized Cut (Spectral Clustering) for Image Segmentation
I have implemented "normalized cut" segmentation. The change here is that, instead of giving an image as input, I have given an matrix of image. As my output looks odd to me. I need to know whether my ...
CommunityBot
- 1
0
votes
1
answer
322
views
State of the art in Cancer tumour detection using Digital image processing algorithms
I am trying to understand how image processing is applied for detection of cancer tumor using image processing. Towards this direction I am trying to get latest information i.e state of the art in ...
CommunityBot
- 1
1
vote
1
answer
216
views
Segmenting dark spots from a light background?
I need to perform automatic segmentation of dark blue spots on light yellow paper. Here's a very simple example:
In this case, a simple threshold based on hue or brightness works well. But here are ...
CommunityBot
- 1
1
vote
1
answer
86
views
Locate No Signal Area Between 2 Signals
I have many datasets which all looks roughly like this:
All the datasets have this in common. First there is an artifact around 0 with an unknown (but likely very high) intensity. Then there is some ...
CommunityBot
- 1
4
votes
1
answer
238
views
Perceptually Corresponding Error Map
Is there any better measurement of error between two images than just taking pixel value differences?
The problem I am tackling is stitching images containing "sensitive" objects, such as moving ...
CommunityBot
- 1
1
vote
1
answer
145
views
Improve Alpha Matting on Hair of Human Portrait
I have an image like this:
I am trying to build a semantic segmentation and matting model which currently gives an output like this:
One can see that some regions between the hair strands are fuzzy....
CommunityBot
- 1
1
vote
1
answer
349
views
How to obtain the relative position (coordinates) of SIFT feature from image center coordinates?
I have extracted SIFT features (keypoints and descriptors) of training set and saved in an inverted index form.
My question is how can I calculate the coordinates of each visual features in an image ...
CommunityBot
- 1
3
votes
1
answer
262
views
How to Find Performance Ratio (PR)?
If we have one image from BSD (The Berkeley Segmentation Dataset and Benchmark) and for this images Ground truth, how to calculate PR?
PR is the ratio of true to false edges, and can be calculated by ...
CommunityBot
- 1
3
votes
1
answer
118
views
How to Make Ground Truth Images for Document Image Binarization Task?
The two images are from DIBCO (Document Image Binarization Contest). The objective is to find a solution to binarize the top image (original image) to be similar to the bottom one (ground-truth image)....
CommunityBot
- 1
4
votes
1
answer
90
views
Image Standardization for Image Classification (Machine / Deep Learning)
I am trying to write a program to standardize an image which I need to better perform image classification. I found the definition of standardisation which is obtained simply by subtracting the mean ...
CommunityBot
- 1
5
votes
1
answer
2k
views
How Do I Plot Color Distribution of HSV Image in MATLAB
I have a dataset of images representing human skin. How do I plot the skin color distribution in HSV color space and YCBCR color space. However, I'd like ignore the "value" or "brightness" in both ...
CommunityBot
- 1
2
votes
3
answers
3k
views
Any good alternatives of ImageJ (Fiji)?
I worked on some medical image processing research two decades ago and I used ImageJ then. I started to pick up some medical image processing projects again (some registration and segmentation). I ...
- 1
2
votes
1
answer
120
views
Thresholding Algorithm for Separating Skin from Clothes
I have an several images that look like the following:
I would like to separate the skin from the trousers here without specifically training a segmentation model. Can anyone suggest any such ...
CommunityBot
- 1
1
vote
0
answers
32
views
Question regarding global thresholding algorithm for images
I am trying to mathematically prove that for an initial choice of threshold To, if we compute the successive thresholds as average of foreground and background means, the thresholds will follow a non-...
- 377
2
votes
2
answers
3k
views
Comparison Between Average Kernel (Box Kernel) and Gaussian Kernel
In image processing, we have two kinds of major kernels that are average kernel and Gaussian kernel. For image segmentation, which is difference between average kernel and Gaussian kernel? I found ...
CommunityBot
- 1
0
votes
0
answers
20
views
Beginner's troubles with binary thresholding for particle tracing in ImageJ
I'm a researcher working on making crystalline microspheres (100-400µm diameter), and have recently begun taking SEM images of my samples. It would be really useful to be able to have a quantitative ...
3
votes
1
answer
116
views
Segmentation of Dark Blobs with Varying Background
I'm new to image processing, but I have good knowledge of general data processing.
Could you please suggest an approach which can be used to segment images like this? I suppose it is some kind of ...
- 20.5k
0
votes
0
answers
12
views
Contrast enhancing very faint extended blobs in an image
I have a series of images of the night sky and I'm looking for methods to enhance very faint structures that are barely visible. The movement of those structures is visible when you click through ...
- 19
0
votes
0
answers
29
views
Detecting a large horizontal band in the center of an image
I have a small (228x228) grayscale image that I have created by segmenting the original image and converting it to grayscale after applying colors to the segment. I want to know possible approaches I ...
- 19
1
vote
1
answer
175
views
Segment Hand Image into Palm and Fingers
Here is my code, i want to extract only the fingers and save them as a new image
...
CommunityBot
- 1
3
votes
0
answers
426
views
Find best fitting rectangles after applying edge detection
I am trying to implement a box detection algorithm. In my pipeline, I start with image warping to simulate a frontal view of the shelf containing the boxes (assuming boxes are straight in that ...
- 20.5k
3
votes
0
answers
264
views
Segmenting Cheese Microstructure (Segmenting Circles)
I'm trying to get the internal geometry of cheese from images of its microstructure:
I tried the canny edge detector and otsu thresholding but neither of these worked very well. I'm guessing that I ...
- 20.5k
2
votes
0
answers
102
views
Compare Active Contours Segmentation (Snake) to Level Sets Segmentation
I am reading about segmentation and I cannot seem to figure out why use active contours over level sets and vice versa. Basically the way I understood it, level sets is relatively the same ...
- 20.5k
3
votes
1
answer
57
views
How to distinguish the same object entering the camera field of view
We want to set photo cameras in the field and capture images of insects that visit flowers. We want to place these cameras above the flowers and then they should get triggered whenever an insect lands ...
- 20.5k
2
votes
0
answers
19
views
Defining the PSNR for images in CIE-LUV or CIE-XYZ or CIE-HCL spaces
In image compression applications, we know that for an 8-bit 0 to 255 level grayscale image the PSNR (peak signal to noise ratio) can be defined through the MSE as:
$$MSE=\frac{1}{mn}{\displaystyle \...
- 121
0
votes
1
answer
111
views
Which is faster: image segmentation or line detection?
Some papers use image segmentation techniques and others use edge detection. I need to know which one is faster.
update:
I need to do semantic segmentation for outdoor sense and the data is optical ...
CommunityBot
- 1
3
votes
1
answer
49
views
Explain the Terms: Semantically Richer and Spatially More Precise in the HRNet Model Paper
High-resolution representations are essential for position-sensitive vision problems, such as human pose estimation, semantic segmentation, and object detection.
From HR-Nets we get semantically ...
CommunityBot
- 1
1
vote
0
answers
83
views
Replicating Hysteresis based Thresholding Technique to an Image from a Paper
I was reading a paper where they applied a hysteresis thresholding to help with segmentation of vessels in an image. It provided a formula to determine how to select a hard threshold (Th), which ...
- 20.5k
0
votes
0
answers
23
views
Lung Detection and Segmentation in X Ray Image
I'm a beginner in image processing and I have to create a segmentation algorithm to detect lungs from an image .
Image given :
And after removing the noise from the image and applying a threshold the ...
- 20.5k
0
votes
0
answers
237
views
Fill Incomplete Holes in 3D Image of Corals
I'm trying to analyse a series of CT scans of coral samples, but am fairly new to this sort of image processing.
The problem I've hit is that a lot of the coral is hollow (in the images), and even ...
- 20.5k
0
votes
0
answers
112
views
How does Arbib's clustering method work?
Recently in Image Processing I've been studying image clustering (or segmentation) methods and one of them is Color Image Segmentation Using Competitive Learning. I understand the main idea behind it ...
- 3,590
7
votes
2
answers
400
views
Locate Non Homogeneous Areas in an Image
I need to choose some points on an image. These points should be chosen more where there is lots of color changes, transitions and variations. Which techniques can I use for determining where most ...
- 20.5k
1
vote
1
answer
56
views
Segment Image of Small Elements on Neutral Background
I have a 8 bit gray level image where if the value = 122 it means no information, value = 0 means highly negative, and value = 255 means highly positive.
I want to connect as many positive information ...
- 20.5k
4
votes
1
answer
123
views
Finding Local mean value of pixels of window
I want to solve the equation (2) in the attached picture which tells the local mean value. But i don't have any idea about how to evaluate this equation using matlab code. could only guess w indicates ...
- 20.5k
2
votes
1
answer
85
views
How to Apply a Texture Classification
I am working in medical and nature images processing.
I want to find a popular method to segment texture image.
Could you suggest an approach to do so?
Both the feature extraction and classification.
- 20.5k
2
votes
1
answer
201
views
How to Reduce the Overfitting of a Linear Classifier
I am working in linear classification such as $$y=ax+b.$$ where $x=[x_1...x_n]$. But the method has weakness that is overfitting problem. Could you suggest to me one method or one way to reduce ...
- 20.5k
3
votes
1
answer
100
views
Find the Mid Point of a Worm / Chain Like Object
I have a video of worm-like objects which move. They can move in a straight line, they can rotate in circles, they can move in a serpentine/winding/sinuous way. I need to track them.
I already have ...
- 20.5k
0
votes
1
answer
91
views
Can Normalized Cut be used to find connected components in binary images?
I'm unsure whether Normalized Cut can or can't be used to find connected components in binary images. I would argue that it could, but could not validate this argument.
- 20.5k
4
votes
1
answer
991
views
OpenCV 2 Connect Incomplete Contours edges
I have to connect the unfinished edges of the contours in the red color bounding box.
I used distance transform, watershed, and morphology, but still, edges are not connecting.
...
- 20.5k
2
votes
1
answer
852
views
Gap Filling Contours / Lines
I have the following image:
and I would like to fill in its contours (i.e. I would like to gap fill the lines in this image).
I have tried a morphological closing, but using a rectangular kernel of ...
- 161
7
votes
1
answer
6k
views
Convolution Kernels for Image Filtering
As I understand it, in image processing, when it is desired to apply a filter of some sort to an 2D image, a kernel is applied to all the pixels of the 2D image in a process called convolution. Median,...
- 3,590
0
votes
1
answer
97
views
Simple technique to segment out optical disk and vessels from retinography
I'm looking for simple techniques to segment out the optical disk and vessels from a retinography. By simple I mean using techniques taught during an introductory course on digital image processing.
I ...
- 2,275
2
votes
1
answer
240
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 ...
- 3,590
2
votes
1
answer
495
views
Can DFT magnitude be used to identify repeating patterns in an Image?
Given the DFT magnitude vector of an 1-D image, I want to understand if we can calculate the size and pitch of repeating patterns in the image. Is this possible? I took a few test images and ...
- 73
0
votes
4
answers
826
views
What is benefit when convert signed 16 bit to unsigned 8 bit in medical image?
I have an image with its type is 16 bit signed. I see some paper, the author often convert it to unsigned 8 bit. But they did not explain why they do it. Could you explain what is benefit of this work?...
- 19
2
votes
2
answers
1k
views
Simple way to detect continuous lines
I have some images of a background, and of steam that I am subtracting to extract just the steam. Unfortunately, because the camera conditions are not perfect the differenced image is always a few ...
- 3,590
1
vote
1
answer
496
views
Removing dark borders in Image Stitching for Panorama
I am working on a Matlab code for panoramic image stitching for multiple image frames and getting satisfactory results however there are always dark regions surrounding the stitched images as ...
CommunityBot
- 1
1
vote
2
answers
1k
views
What does convolving an image with kernel [1 -2 1] do? How is it different than convolving with the derivative kernel [1 -1]?
What does convolving an image with the filter [1 -2 1] do? I see that it's a form of edge detection but it's also very similar to the results I get when convolving with the derivative kernel [1 -1] so ...
- 2,760