All Questions
269 questions
-1
votes
2
answers
2k
views
Segmentation of warped text lines
I am trying to segment warped text lines found in photos taken from a page of a book (from the camera of a smartphone). This is meant as a preprocessing step before running OCR on them.
I have found ...
- 37
4
votes
2
answers
4k
views
Scikit-Image, Numpy, and Selecting Colors (python)
I'm trying to mask colored features from a photograph so that I can do some other processing on them. I've played with a few packages (scikit-image, mahotas, and openCV) and have settled on Scikit-...
- 161
1
vote
1
answer
198
views
Image Processing- ornament detection
So I am working on a project where we are supposed to detect and count the red and gold ornaments in the picture provided in the link below. I am having issues detecting and counting each ornament and ...
- 11
0
votes
1
answer
66
views
Turning a MPG video into a set of coordinates
I have a video in MPG format showing a white mouse with a strong black dot on the head moving around on an off-white background, so effectively a black dot moving around on a 2-D plain surface. From ...
- 103
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 ...
- 185
0
votes
2
answers
1k
views
Method to remove small unwanted region and fill holes for specific image
I have a binary image that maintains some unwanted region (small white dot) and hole regions (in figure 1). My idea is that to fill the object after I will remove the unwanted region but I don't now ...
- 1
1
vote
2
answers
82
views
Separating near points
I'm programming in matlab. I have processed image:
How can I separate them some thing like this:
In other words, I want to separate points that are near together without morphological operations.
I ...
- 146
0
votes
1
answer
2k
views
How we can use the Hadamard transform in feature extraction from an image?
Which coefficients of the Hadamard transform contain the highest energy compaction? Is there any regular pattern in them as for the DCT?
- 63
1
vote
0
answers
215
views
What is a good algorithm, and framework, to calculate centres of gravity or mass (cog)? [closed]
I'd like to take an photograph, subdivide it into a tesselation, either of squares, or (ideally), hexagons, and then find the centre of gravity (or, if you prefer, centre of mass) of each cell of the ...
- 111
3
votes
1
answer
678
views
Best way of segmenting veins from arm?
I have done fews researches and found out approach such as
multiscale and
region growing,
that could be used of extracting forearm veins.
However, I tried to use frangi filter and Figure 1 is the ...
- 31
2
votes
2
answers
2k
views
Comparison between watershed and grabcut
I know that watershed and grabcut algorithms are both common tools for image segmentation. They both seem to rely on predefined markers to form something like a source-sink system and then uses the ...
- 155
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 ...
- 131
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 ...
- 121
0
votes
1
answer
180
views
How to get Harris corners that are present in watershed segmented Bitwise image(road part)?
This is Harris corner image of test image:
This is Bitwise watershed segmented image:
I want to get that Harris corners which will be in segmented part of image(road part).
3
votes
0
answers
223
views
Fast greyscale image segmentation on 16x16 image
I have a 8-bit greyscale 16x16 image where I want to extract coherent shapes with a more or less consistent pixel arrangement if possible (like: a rectangle, staircase, line). Currently, I'm doing ...
- 31
1
vote
0
answers
125
views
Is there a way to detect ambiguous edges?
I'm writing a program that can detect veins(the dark lines) on an arm.
When looking at the image at full size, you can easily make out where they are.
But when zoomed in around a vein I get ...
- 65
1
vote
1
answer
4k
views
Calculate sum of absolute difference per pixel
I am trying to implement a research paper just to verify my results. I have shared the code (written by me) and the description of the process given in the research paper. Unfortunately my results are ...
- 111
1
vote
1
answer
79
views
Connecting segmented region in image
I am working on segmenting hands from monocular images and I have already come up with a pretty descent segmentation. The only issues I am having are when people have rings on their finger. Then the ...
- 115
1
vote
2
answers
247
views
Segmentation of small artifacts - Image Processing
I am working on a task of segmenting small artifacts from a set of images like below:
I am looking for a generic approach, but unsure of what to search?
I tried looking at density flow analysis, but ...
- 111
5
votes
1
answer
2k
views
How does image masking work?
I am new to image processing and I am interested how image masking can be used to extract a portion of a image.
Have a look at this OpenCV tutorial.
In the section Application of Mask, they say that ...
- 151
2
votes
0
answers
237
views
How to properly detect segments in a LCD segment display
I have been given the task to develop a code which checks if the display of a device is showing information correctly (i.e. any segments are activating when they are not supposed to).
To meet this ...
- 121
2
votes
0
answers
95
views
How to classify images based on the amount of colors in the image?
I have a problem where all images have the same object; however, these objects can either have number_of_colors<=3 OR number_of_colors>3 and images are not labeled.
My attempt starts by ...
- 21
0
votes
1
answer
104
views
Automatic landmarks on images of hands
Problem statement
I am starting a project soon where I need to create a method to automatically create landmarks on a set of images of human hands. I do not have a sample image but the images are ...
- 115
1
vote
1
answer
193
views
What Is the Difference Between MRF and Total Variation in Noise Removal?
I have a general question in image processing. I have a noisy image. I would like to classify the noisy image into some regions. Two famous approaches I can use are:
MRF/Gibbs MRF: Model the spatial ...
- 205
-1
votes
1
answer
168
views
Add padding to object in 4-channel image
I have a 4-channel image (.png, .tif) like this one:
I am using OpenCV, and I would like to add padding of type BORDER_REFLECT around the flower. ...
- 121
1
vote
2
answers
1k
views
Generate a nonuniform illumination (bias field) 2D image
I am creating a nonuniform illumination in MATLAB R2015. The nonuniform illumination (known as bias field) is defined as
Nonuniform Illumination (intensity inhomogeneity) which manifests itself as ...
- 211
5
votes
2
answers
1k
views
Deriving the Euler-Lagrange Equations for the Chan-Vese Model
I am reading the Chan-Vese paper "An Active Contour Model without Edges" and IPOL tutorial "Chan-Vese Segmentation" by Pascal Getreuer. The energy for this model is given by:
$$
E(\varphi) = {\mu \...
- 91
3
votes
2
answers
525
views
Detecting Central Axis (petiole/rachis) of a Pinnated Palm
I'm new in StackExchange and I'd appreciate some help. I'm working in an algorithm for detecting "aguajes", a particular kind of palm. So far, I got good results using a texture feature extractor and ...
2
votes
1
answer
304
views
What is a good way to locate butterfly in an image
I have some images of butterflies. I've downloaded them from here. A sample is below:
In each image, the most prominent object is the butterfly (with flowers, leaf etc in background). I usually go ...
- 141
4
votes
3
answers
2k
views
Vein extraction from this image
I have this image:
What methods should I use to extract the veins from this image.
Thank you.
- 41
1
vote
1
answer
699
views
Saliency Map based on itti model
i want to create a Saliency Map based on itti model via OpenCV(Python). what i'm doing is that:
1- first i change image color space from RGB to LAB color space
2- for each color channel, i create a ...
- 143
0
votes
1
answer
396
views
What type of images are required for voxel classification?
In an algorithm, voxel classification approach is used to perform image segmentation. The aim was classifying voxels either as ...
2
votes
1
answer
129
views
How to quantify area of interest in an image?
How to find the percentage of a certain colour in a image accurately? For example I am actually trying to find the percentage of barnacles in this image over the red part of the hull.
http://thumb1....
- 23
0
votes
0
answers
49
views
Counting percentage of fouling on a surface
I am completely new to image processing and python. I hope I can find some help here. I am trying out a project on detecting fouling% on a ship hull using raspberry pi. I am trying to learn how this ...
- 23
1
vote
1
answer
172
views
What is the best approach to classify an image containing either text or image?
I am doing a research about image-based User Interface (UI) Analysis, and while UI image-based analysis is not more complicated than normal image analysis, I was able to do a segmentation process to ...
- 131
1
vote
3
answers
530
views
The model of noise in Image denoising problem
I am studying the image denoising problem. The paper I studied uses Gaussian Noise to model the noise appearing on the image. E.e., If we say $u_g$ is a clean image, then we model the noisy image $u_0$...
- 121
0
votes
2
answers
787
views
Magnitude of Sobel filter result, vector or scalar?
I have a question about image gradient magnitude, given an image $I$. The horizontal and vertical derivatives resulting from Sobel filters are defined as:
$$K_x=
\begin{bmatrix}
-1 &...
- 585
0
votes
2
answers
82
views
How to represent a given equation more clear, profressional and short form?
I have a image $U_{m \times n}:\Omega \to \mathbb R^2$, the output $P$ can be define as
$$P=\mu J_{m \times n} - U$$
where $\mu = \max \{ u_{ij} : 1 \leq i \leq m, 1 \leq j \leq n\}$, $J_{m \times n}$...
- 211
6
votes
1
answer
118
views
What Is "Description Vector" in Image Processing?
When we want to use classifiers like SVM, we first should extract descriptors using algorithms like SIFT.
But I have a question which might call a silly one:
Let's assume
$$
\begin {equation}
D_a=\{...
- 783
1
vote
2
answers
648
views
Segment highly packed nuclei with dotted high intensity signal inside each object
I collected high magnification images on cell nuclei and I need to segment them (red circle in the image). The edges of the nuclei are visible but inside each nuclear object there are bright spots of ...
- 119
1
vote
3
answers
323
views
selecting bricks from image
I have an image of bricks of different sizes. What I want to do is when I click on the corner of the brick it should mark the lines around the brick. Can anyone please help me how can I do that...
...
- 423
1
vote
1
answer
514
views
What is "find-grained" image?
What does exactly and precisely the term "fine-grained" mean in image segmentation?
For example, undeniably, the picture below is a fine-grained image:
But is it correct to call below picture as a ...
- 783
0
votes
1
answer
364
views
Converting blobs to circles
I have this binary image with some blobs of random sizes.
I would like to convert the blobs into circles of uniform diameter. it doesn't really matter what diameter but they need to be circles and ...
- 101
1
vote
2
answers
618
views
Filling hatched areas in image
I'm trying to extract / fill the walls in a floor plan, the walls are filled with a (cross-)hatch pattern at a more or less fixed angle.
I've managed to remove most of the "noise" by masking the DFT ...
- 121
1
vote
0
answers
130
views
Segmenting simple objects without shadows
I am trying to segment very simple objects like boxes and bottles. I am using GrabCut and it works extremely well when there are no shadows or when the shadows are soft - but as soon as there is a ...
- 133
-1
votes
1
answer
118
views
Convergence criteria for Active contour model
Currently, active contour convergence is checked visually.
So how can we set a convergence criteria?
I looked into some unsupervised segmentation method for image segmentation but couldn't got a ...
- 147
2
votes
1
answer
169
views
Identify large solid color areas of image
This is a simple image classification problem. I want to categorize jigsaw puzzle images to difficulty levels (e.g, easy, medium, hard).
I want to develop an simple algorithm for this classification, ...
- 21
4
votes
1
answer
845
views
How to Use Maximum a Posteriori Probability (MAP) in Classification Task
I have a 2D image defined on a region $\Omega$. Let $I: \Omega \to R$ be a gray image. Assume that the region can be separated into $N$ sub-regions $\Omega_i$ such that $$\forall i,j=1,\ldots ,N:\...
- 585
2
votes
1
answer
104
views
How to prove $\int_{\Omega} \sum_{i=1}^{N} f_i(x)dx$ is equivilant with $\sum_{i=1}^{N} \int_{\Omega} f_i(x)u_i(x)dx$
I have a 2D image defined on a region $\Omega$. Assume that the region can be separated into $N$ sub-regions $\Omega_i$ such that $$\forall i,j=1... N:\Omega_i \cap\Omega_j=\emptyset$$ and $$\bigcup_{...
- 211
0
votes
0
answers
34
views
To estimate the uncertainty of Slicing holes from an image?
I am thinking to estimate the uncertainty of holes photographed from the bottom and top side.
The difference of the same hole photographed from two sides is distributed as Gaussian.
The length of ...
