Histogram Viewer

Histogram Viewer

Generates the histogram of a selected image.

What is Histogram Viewer?
Histogram Viewer is a Firefox add-on that generates histograms of selected images. It provides options to generate grayscale histograms, display statistics, and show histograms for individual color channels.
Users: 236 ▼ -8
Rating: 4.67 (3)
Version: 3.0.0 (Last updated: 2018-03-02)
Creation date: 2008-09-04
Weekly download count: NaN
Firefox on Android: Yes
Risk impact: Moderate risk impact
Risk likelihood: Low risk likelihood
Manifest version: 2
  • *://*/*
  • file:///*
  • activeTab
  • contextMenus
  • storage
Size: 13.74K
URLs: Website
Stats date:

Other platforms

Not available on Chrome
Not available on Edge
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The Histogram Viewer generates the histogram of a selected image. When the user right clicks on an image, the option "Show Histogram of Image" is shown in the context menu. If the user selects this option a new window is opened which shows the histogram of the image.

By default the histogram is generated based on the sum of all 3 RGB color channels. Additionally the histogram for each of the 3 color channels can be shown. Some statistics about the histogram are also shown.


  • Grayscale histogram
  • Option to select the way the grayscale histogram is calculated   * all color channels have the same weight   * the color channels are weighted according to the human perception (gray = 0.299red + 0.587green + 0.114*blue)
  • shows histograms for each color channel
  • shows statistics about the histogram: min, max, mean, median
  • optional hiding of the statistics
  • shows the individual value and its number of occurrences, when the user moves the mouse over the histogram
User reviews
I do a lot of photography, and Iook at a lot of other people's photographs. I think in terms of image histograms a lot, and being able to quickly glance at the histograms of pictures I'm viewing on line is VERY handy. This plugin does that excellently, I've used it for years and years now.
by dd-b, 2023-03-21
View all user reviews
Risk impact

Histogram Viewer may not be safe to use and it requires some risky permissions. Exercise caution when installing this add-on. Review carefully before installing.

Risk likelihood

Histogram Viewer has earned a fairly good reputation and likely can be trusted.

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