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Questions tagged [contrast]

the difference in color and light between parts of an image

281 questions
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How do you programmatically lighten or darken a dynamic Color in SwiftUI?

Others have covered how to lighten and darken UIColors in Swift, but I have not seen a good way to programmatically "lighten" and "darken" dynamic SwiftUI Colors. I have green Text using Color(.systemGreen) that I would like to appear darker on…
Nik Payne
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How can I make the font rendering in VSCode for MacOS looks exactly the same like VSCode for Windows?

Somewhat the opposite of this question. I don't like how fonts are rendered in VSCode for Mac. To me, the lack of contrast gets in the way, since I don't have good vision, the letters get a little scrambled because of the lack of contrast. I can…
Edgar Froes
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How to mimic Microsoft Photos's Clarity feature in ImageProcessor library

I'm trying to improve the identification of a facial recognition in a photo, because sometimes no face is detected using Microsoft's Face API. In this scenario I want to try to improve the quality of the photo. When I do this manually in Microsoft's…
Calvin Sellers
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How do I adjust brightness, contrast and vibrance with opencv python?

I am new to image processing. I program in Python3 and uses the OpenCV image processing library.I want to adjust the following attributes. Brightness Contrast Vibrance Hue Saturation Lightness For 4, 5, 6. I am using the following code to convert…
Antonie Lin
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Do unselected checkboxes need to be >4.5 contrast ratio to be WCAG AA compliant?

I'm trying to understand the details of WCAG AA compliance. Would the unselected checkboxes in this image be considered too low-contrast to be compliant? Is there anything we can do (other than change the color) to make it more compliant? If…
Brian Genisio
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how to get the contrast value of an image in python opencv?

I want to know the contrast for traffic density data. I have searched but found no matching result to get the contrast value of an image in python opencv does anyone know?
aku putri
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R: Special contrasts within an interaction effect

Within the context of a 2-way ANOVA, I would like to enter contrast levels for one factor (10, 20, 30 degrees) within levels of another factor (SpeciesA, SpeciesB). This assumes the interaction effect is significant so the contrasts cannot simply be…
B. Bingham
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Finding color matrix for Brightness and contrast for iOS Application

I checked out the color matrix for brightness and contrast and I got {contrast, 0, 0, 0, brightness 0, contrast, 0, 0, brightness 0, 0, contrast, 0, brightness 0, 0, 0, 1, …
anamika41
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Android: Changing image contrast and brightness upon scrolling seekbar

I would like to set the contrast and brightness of a imageview. Referring from How to programmatically change contrast of a bitmap in android?, which should be the most fastest and efficient way of doing so, I have implemented the code as…
pearmak
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How to change image contrast and hue with RenderScript

I've been using android's RenderScript for about a month and I can't figure out, how I'd change a contrast with it. I've been able to change Brightness, Blur, and Saturation, but I'm stuck with Contrast and Hue. I know that it's possible to change…
Fedor Tsyganov
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The Concept of Homomorphic Filtering

I am trying to understand the concept of homomorphic filtering, I have read several online pages about this topic such as http://en.wikipedia.org/wiki/Homomorphic_filtering However, I noticed a scarce online resources that discuss this topic.…
Traveling Salesman
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How can I perform in-browser contrast stretching/normalization?

I have jpegs on a webpage. I would like to perform client-side equalization (contrast stretching) on these images without browser plugins. I would also accept a solution for histogram equalization. I currently use a poor approximation with a…
Nils Enevoldsen
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Using ImageMagick++ to modify image contrast/brightness

I'm trying to apply contrast and brightness to a bitmap in memory and I'm completely lost. Currently I'm trying to use Magick++ to do it, but if one of the other APIs would work better I'm all ears. I managed to find…
Justin G
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Changing image contrast with GDI+ and C#

My problem is the following : I am making a program, which can manipulate brightness, gamma and contrast through C# code. For brightness and gamma it is OK. I have achieved it through code I found in the net, but I can't for contrast. The only…
Yoan Petrov
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How do you find the color contrast using APCA (Advanced Perpetual Contrast Algorithm)?

So I wanted to write a color contrast calculator for a given pair of foregroundRGBA and backgroundRGBA colors, using the Advanced Perpetual Contrast Algorithm (APCA) (read Google WebDev's mini-article on APCA). While the aforementioned site has some…
SFM61319
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