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OpenCV Android Programming By Example

You're reading from   OpenCV Android Programming By Example Leverage OpenCV to develop vision-aware and intelligent Android applications.

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Product type Paperback
Published in Dec 2015
Publisher
ISBN-13 9781783550593
Length 202 pages
Edition 1st Edition
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Enhancing the image contrast

Now that you understand what a histogram is and how to calculate it, it is time to look at one of the most widely used image enhancing techniques: the histogram equalization. The histogram equalization technique is used to enhance the image contrast, that is, the difference between the minimum and maximum intensity values in order to strengthen image details that could be washed out.

Understanding histogram equalization

From an abstract point of view, what the histogram equalization does is it finds a function that takes the image's original histogram and transforms it to a stretched histogram with a uniform distribution of the image intensity values, thus enhancing the image contrast.

In practice, histogram equalization doesn't produce a perfectly equalized output histogram; however, it forms a good approximation of the needed transformation that spreads the intensity values more evenly over the defined equalization range of the image:

Understanding histogram equalization

Enhancing grayscale...

You have been reading a chapter from
OpenCV Android Programming By Example
Published in: Dec 2015
Publisher:
ISBN-13: 9781783550593
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