Questions tagged [histogram]
The histogram tag has no usage guidance.
17
questions with no upvoted or accepted answers
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20 views
Multivariate Histogram Matching for Image Color Matching
Suppose X is random variable that is spatial position in finite range, which its Cumulative Distribution Function (CDF) could be calculated easily, then if I have two random variable X and Y spatial ...
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0answers
41 views
I can't implement plateau limit histogram equalization algorithm using MATLAB
i tried to implement this research paper using MATLAB. Unfortunately, my result is not same with the original result.
Here is my try step by step:
...
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91 views
Applications for adaptive and non adaptive histogram equalization
I have a question regarding histogram equalization and adaptive histogram equalization.
In which circumstance would it be preferable to use adaptive histogram equalization over histogram equalization ...
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0answers
64 views
Watermark insertion process in image
I'm new in the field of image processing and I'am trying to implement a watermarking algorithm (for medical images in DICOM format) based on this paper.
As written in the paper, this algorithm is ...
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0answers
2k views
Measuring sharpness/contrast for autofocus
For the implementation of an auto-focus for the raspberry cam I need some measure of image sharpness. I used the following sample picture:
The first approach was to compute the shannon entropy of the ...
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2answers
613 views
CLAHE - Redistributing excess pixels among histogram bins
In order to clip an image's histogram to a maximum value, according to the CLAHE algorithm, the excess pixels (above the clip limit) will be distributed equally among all the histogram bins (While ...
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117 views
Gonzalez question solution
If I have the histogram of an input image as Gaussian probability density function of the form:
$$P_r(r)=\dfrac{1}{\sqrt{2\pi}\sigma}e^{-\dfrac{(r-\mu)^2}{2\sigma^2}} $$
where: $\mu$ and $\sigma$ ...
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0answers
454 views
GLOBAL THRESHOLDING using histogram
There is a recursive way of finding threshold in the image using histogram that are biomodal, and is as follows:
An automated procedure for bimodal histograms :
Select an initial estimate of T
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0answers
880 views
Local histogram equalization
I want to learn computer vision and so I downloaded image processing slides from my university archive. I'm on histogram equalization. Learning about local histogram equalization points me out to this ...
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30 views
How to solve this math problem regarding Histogram matching?
Please help solve the problem in the picture. I am confused due to the piecewise nature of the density functions. If it was a simple curved PDF, I would simply integrate over full range and use the ...
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8 views
quantification of histogram equalization improvement
My project consist of classification of images using ML. The images are microscopic slices. For the feature extraction phase, I am using multiple filters and got a good result.
So I decided to do a ...
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0answers
18 views
Which are the rules of choosing a target image for histogram matching?
With histogram matching we can transform an image's intensity distribution. But this idea is very subjective. Sometimes for choosing a target image we have options no better than a guess. But is their ...
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12 views
Computing White Speckle Metric in a Document Image
The paper 'Metric-based No-reference Quality Assessment of Heterogeneous Document Images', discusses about measuring the quality of characters in a document image. I'm having difficulty to understand ...
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1answer
99 views
Harmonics in Quantal Histogram
I'm studying what I believe to be a system that produces a (noisy) quantal response (i.e. there should be a minimum increment of response). To do this, I've plotted a histogram of some ~6000 amplitude ...
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145 views
How do i detect if an image has a gradient or not?
I have coloured images, some may be just clipart, some may be artwork, both could be with or without gradients.
Before i run a colour counting algorithm on them, i want to detect if the image has ...
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0answers
576 views
Distance-metric for SIFT descriptors matching
Will using Cosine-Similarity or Histogram Intersection as distance-metric, for matching SIFT descriptors, help to get better results?
Anybody tried on that ever?
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164 views
Encoding the HOG features
I have got a video containing 200 frames and i am extracting low level features at pixel level. Then i am dividing the entire frame in to small spatial patches (say of size 7x7) and creating a feature ...
