Image Comparison
Image Comparison
Embedded Files
The image comparison module is designed to compare different images together.
The window contains 3 widgets :
the settings widget on the left contains an histogram and a chromaticity diagram (visible if the current output is RGB), settings to select the file and layer to display, and the post process applied to the image on the left,
the settings widget on the right contains the same settings for the image on the right,
the preview widget contains a preview of the resulting post processed images. The footer of the preview widget contains the display settings to choose and define the comparison mode.
If the selected images don't have the same resolution, the second image will be resized and/or cropped to fit the first image aspect ratio.
Using this module, the save button has the following options :
LDR output : the processed output (the image currently displayed on screen) saved to a *.png file,
HDR output : the processed output (the image currently displayed on screen) saved to a *.exr file, note that only the RGB layer will be exported.
See the Raw Data Preview module documentation for more details on the histogram, gamut, effects and mapping sections or the settings widget.
Slide Comparition
Slide Comparition
The horizontal slide comparison mode enables you to place both images at the exact same position and display one or another using an horizontal slider. This is especially useful to compare visually two images.
You can select a different file and layer for each image to compare, and apply a post process to each image individually.
Parallel Comparison
Parallel Comparison
The parallel comparison mode enables you to compare both image side by side.
Delta E
Delta E
The DeltaE is a metric that defines the distance between two colors. It is an analysis metric used to define whether or not two colors can be differentiated : typically it is accepted that when the DeltaE is inferior to 2.0 the colors cannot be differentiated by the human eye. We are currently using the CIEDE2000 formula published in 2001.
Some additional settings are available in the preview widget footer :
the color map used to visualize the DeltaE values,
the minimum and maximum values displayed by this color map (a reset button enables you to display the entire range of values in the current image),
the ID of the pixel used as reference for the white balance : the color of this pixel will be considered as a perfect white and all other pixel values will be divided by this color (if the ID is negative, no white balance will be made).
When placing the mouse over a pixel, its value is always displayed on the top right corner of the preview widget, this is a great way of knowing the precise DeltaE value of a pixel.
The DeltaE must be computed in the XYZ color space.
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