# Tagged Questions

Non-linear operators in Mathematical Morphology is the theory of using algebraic structure of lattices and geometrical analysis of structures, based on set theory, topology, and random functions. operators: Erosion, Dilation, Opening and Closing. Reconstruction filters, Connected filters, ...

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### How to get the inner border of a shape after a dilation

I'm working on custom shapes, like circles, rectangles and so on. Let some variables here: width = W height = H Kernel: rectangle with size: W*H I have to do a ...
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### Morphological transformations for images with discrete values

I have a series of images in which the pixels take integer values corresponding to a classification. I'd like to try some morphological transformations (e.g. erosion, dilation) to remove noise and ...
133 views

### Granulometry by morphological opening and closing

I am trying to understand granulometry. I understand that it deals with determining the size distribution of particles in an image and uses the principles of opening and closing. I have a smoothed ...
397 views

### Segmentation of overlapping noisy parallelograms in a binary image

Edited. Previously this question was named "Segmentation of overlapping pulses in a binary spectrogram" and it was stated in slightly different way. I'm apologise to those users, who were affected by ...
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To obtain the gradient from an image, one can use a linear filter that for example is derrived from the derrivative of a gaussian. Then convolving the image with this linear filter gives you the ...
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### 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 ...
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### Using morphological operations for color images processing

Have you ever seen any articles about using morphological-like technique for denoising color images?
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### OCR (optical character recognition) for Indian languages - segmentation

Can any one help me in how to extract a table from the whole document image and segment it? I have done segmentation for the document image which has only text by using the projection profile. So ...
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### Best way to remove unwanted region from image

I am finding the techniques to remove unwanted regions (small dots) from image. I have an image that includes object and some unwanted region (small dots- see first image). I want to remove it. Hence, ...
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### Computations in Grayscale morphology dilation

I red this link, but unfortunately i still don't understand the process... By the way, Dilation process is performed by laying the structuring element H on the image I and sliding it across the image ...
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### Decomposition of **3D** structuring elements for morphological operations

I am struggling to implement a mathematical morphology toolset in an image processing package. I base my implementation on what I saw in MATLAB, and on several papers on the subject. There seems to ...
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### Uneven background subtraction: Rolling ball vs Disk tophat

A classical technique in still images (e.g. fluorescence microscopy images) to remove uneven illumination and isolate bright blobs is to use morphological operation such as the top-hat transform. For ...
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### OpenCV: Problem at creating a Skeleton of Lines

I need to get the lines from a photographie of a sheet of paper. While recherching, I came along this, where one answer referred to this blog entry. Now I am having trouble with this approach. I have ...
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### Erosion in image

I don't if I am posting my question in the correct place. I have tried hard to solved it but I am unsuccessful. I have an structuring element shown below: ...
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### Image processing: how do I erode on boundary and dilate inside boundary?

I have an image that I am trying to process: I want two seamingly contradictory effects: I want to remove "holes" inside "the blob". That is I want all pixels inside the blob to be solid red. I ...
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### Find branches in skeleton image using matlab

I have a skeleton image. I am able to detect branchpoints, endpoints and able to label image using BWMorph, BWLabel. Now I want to differntiate between skeleton center line and branches. In short I ...
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### Grayscale morphology

Hello I've been trying to understand the grayscale dilation operation using the following example, but my results are different. \$I = \begin{pmatrix} \bf{5} & 2 & 4 \\ 1 & -3 & 1 \end{...
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### Shape of structuring elements for morphological gradients

I am looking to understand recommended shapes of structuring elements used in calculating morphological gradients. According to Pierre Soille: Morphological Image Analysis: Only symmetric ...
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### OpenCV/C++ connect nearby contours based on distance between them

I have to connect nearby contours in an image based on the distance between them which specifies if the contours are to be connected. Now there's a question already on the same problem here http://...
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### On the de-noising of time-frequency images

I am wondering what techniques might be available for 'de-noising' the following example time-frequency image that was created using Welch's method. The following plot was created from a robotic ...
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### How to: pixel packs in an image to representative point coordinates (x,y)

Let's have an image (gray-scale or even binary) as shown on the following figure at the left hand side, the goal is to generate a list of points i.e., coordinates in the form of (x,y) for each pack of ...