Image viewer

• Image navigator
• Image View Controller
  • Histogram
  • White Balance
  • Bayer demosaicing
  • Alpha Blending

Image navigator

Use Image navigator tool to navigate into image.

• Click into image with Left mouse button to set center of zoom,
• Use mouse wheel to zoom-in/zoom-out centered in by the white cross,
• Use (1) button to have zoom 1:1,
• Use (-) or (+) buttons to change zoom, or zoom slider,
• Use Best zoom button to get whole image fitting in current image window,

You can also navigate directly into image.

• Click into image with Left mouse button to set center of zoom,
• Use mouse wheel to zoom-in/zoom-out,
• Use keys (-) or (+) to zoom-in/zoom-out,
• Click into image with Left mouse button down and move mouse to move image,
  release mouse bouton when move is done,
• Use arrow keys to move image point of view.

Image View Controller

Image View Controller is a powerfull tool to see some image details without modifying original image. Note that using Image View Controller has no effect on how the image is stored in memory. It only changes how it is displayed on the sceen.

When using resolutions higher then 8-bit we are standing in human visualization problem: the number of gray levels available for display an image is much lower than the number of levels in the image. Without processing it's hard to see all the dynamics of an image just with one visualization. A solution is to set a threshold low an a high level to be seen. We add a Midtones transfert function to improve detail enhancements at low or high level.

Histogram

You can see image histogram, clicking Show histogram button in Image View Controller tool.

You can hide histogram, clicking Show histogram button in Image View Controller tool.

• Grey bars are histogram of image luminance,
• Red curve is histogram of red channel,
• Green curve is histogram of green channel,
• Blue curve is histogram of blue channel,
• White curve is histogram of alpha channel,
• Yellow curve is viewer transfert function (linear here).

Code sources: src/Image/ImageHistogram.cpp, src/Image/Analyse/Histogram.hpp

White Balance

You can control the white balance of your image. Click Show colors setting button in Image View Controller tool.

You can control to see/hide color channels and adjust the white balance.
Check WB box to activate white-balance, then you can select the amount of red, blue and green.
You can also Pick the color that could be seen as white pushing the pipe button, that clicking at pixel location of the image white reference. Reset the white balance setting pushing the right button.

Code sources: src/Image/PointProcessing/Balance.hpp, include/elx/math/inl/Ramp.inl

Bayer demosaicing

With Bayer images (RAW images from cameras) you can control the Bayer to color used algorithm for display.

Code sources: src/Image/Bayer/

Alpha Blending

You can control to enable or disable the blending for image with an alpha channel with the checker button.

Blending on

Blending off