Visual

Textual and Visual Comparison Of Images

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About

Published on Maven Central that compares 2 images with the same sizes and shows the differences visually by drawing rectangles. Some parts of the image can be excluded from the comparison. Can be used for automation qa tests.

Configuration

All these configurations can be updated based on your needs.

Property Description
threshold The threshold which means the max distance between non-equal pixels. Could be changed according size and requirements to the image.
rectangleLineWidth Width of the line that is drawn the rectangle.
destination File of the result destination.
minimalRectangleSize The number of the minimal rectangle size. Count as (width x height). By default it’s 1.
maximalRectangleCount Maximal count of the Rectangles, which would be drawn. It means that would get first x biggest rectangles. Default value is -1, that means that all the rectangles would be drawn.
pixelToleranceLevel Level of the pixel tolerance. By default it’s 0.1 -> 10% difference. The value can be set from 0.0 to 0.99.
excludedAreas ExcludedAreas contains a List of Rectangles to be ignored when comparing images.
drawExcludedRectangles Flag which says draw excluded rectangles or not.
fillExcludedRectangles Flag which says fill excluded rectangles or not.
percentOpacityExcludedRectangles The desired opacity of the excluded rectangle fill.
fillDifferenceRectangles Flag which says fill difference rectangles or not.
percentOpacityDifferenceRectangles The desired opacity of the difference rectangle fill.
allowingPercentOfDifferentPixels The percent of the allowing pixels to be different to stay MATCH for comparison. E.g. percent of the pixels, which would ignore in comparison. Value can be from 0.0 to 100.00
differenceRectangleColor Rectangle color of image difference. By default, it’s red.
excludedRectangleColor Rectangle color of excluded part. By default, it’s green.
imageResizeFlag Resize the image equal to expected image before comparison . Default to False
imageResolution Sets the image resolution. Default to 70
extractText Sets the flag to do textucal validation. Default to false
language Required if extractText flag is True, download the file for the language and sets the path
coordinatesToExcludeFilePath Path of the file containing the coordinates to exclude from validation. All included if left blank
printCoordinates Prints the coordinates of failures on image if true. By default false

Usage

Maven

<dependency>
    <groupId>in.testonics.omni</groupId>
    <artifactId>visual</artifactId>
    <version>1.0.2</version>
</dependency>

Gradle

compile 'in.testonics.omni:visual:1.0.2'

To compare two images programmatically

Default way to compare two images looks like:
        //Sets the object of Visual Comparison
        VisualComparison visualComparison = new VisualComparison();

        //By default, result file will be saved at root location of the project
        File file1 = new File(".\\ImageExpected.png");
        File file2 = new File(".\\ImageActual.png");
        VisualComparisonResult visualComparisonResult = visualComparison.compareImages(file1, file2);
Save result image at custom location

Use the setDestination method of VisualComparison

        //Sets the object of Visual Comparison
        VisualComparison visualComparison = new VisualComparison();

        //Optional : If not set, result file will be saved at root location with the name "results.png"
        visualComparison.setDestination(new File(".\\target\\results.png"));
        
        File file1 = new File(".\\ImageExpected.png");
        File file2 = new File(".\\ImageActual.png");
        VisualComparisonResult visualComparisonResult = visualComparison.compareImages(file1, file2);
Enable Textual Comparison
  1. Set the extractImage flag as True and Set the path of the language file 
         //Sets the object of Visual Comparison
     VisualComparison visualComparison = new VisualComparison();

     //Optional : If not set, result file will be saved at root location with the name "results.png"
     visualComparison.setDestination(new File(".\\target\\results.png"));
     visualComparison.setResizeImage(true);

     //Set below parameters if textual comparison is required
     visualComparison.setExtractImageFlag(true);
     //Download the language file from the link and set the folder path
     visualComparison.setLanguagePath(".\\language");

     File file1 = new File(".\\ImageExpected.png");
     File file2 = new File(".\\ImageActual.png");
     VisualComparisonResult visualComparisonResult = visualComparison.compareImages(file1, file2);

     //Print the results as needed
     System.out.println("Percentile Mismatch : " + visualComparisonResult.getDifferencePercent());
     System.out.println("Textual Mismatch : " + visualComparisonResult.getMismatch());

Demo

Demo shows how Visual works.

Expected Image expected

Actual Image actual

Result result

Print the Failures To Assert

        //Image Percentile & Text Mismatch can be printed using VisualComparisonResult.
        System.out.println("Percentile Mismatch : " + visualComparisonResult.getDifferencePercent());
        System.out.println("Textual Mismatch : " + visualComparisonResult.getMismatch());

Retrieves the text from an Image

        //Image Percentile & Text Mismatch can be printed using VisualComparisonResult.
        System.out.println(Image.getImageText("Image.png"));

License

This project is Apache License 2.0 - see the LICENSE file for details

Release Notes

Can be found in RELEASE_NOTES.

Code of Conduct

Please, follow Code of Conduct page.

Also if you’re interesting - see my other repositories