Verify.ImageSharp

Extends Verify to allow verification of documents via ImageSharp.

See Milestones for release notes.

Sponsors

Entity Framework Extensions

Entity Framework Extensions is a major sponsor and is proud to contribute to the development this project.

Developed using JetBrains IDEs

NuGet

• https://nuget.org/packages/Verify.ImageSharp

Usage

[ModuleInitializer]publicstaticvoidInit()=>VerifyImageSharp.Initialize();

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Verify a file

[Test]publicTaskVerifyImageFile()=>VerifyFile("sample.jpg");

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[Test]publicTaskVerifyImageFileWithCustomEncoder()=>VerifyFile("sample.jpg").EncodeAsPng();

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Two files are produced

Info file:

Samples.VerifyImageFile.verified.txt

{
Width: 1599,
Height: 1066,
HorizontalResolution: 1.0,
VerticalResolution: 1.0
}

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Image file:

Samples.VerifyImageFile.verified.jpg

Verify an SixLabors.ImageSharp.Image

An instance if an SixLabors.ImageSharp.Image can be verified using the following:

[Test]publicTaskVerifyImage(){varimage=newImage<Rgba32>(11,11){[5,5]=Color.ParseHex("#0000FF").ToPixel<Rgba32>()};returnVerify(image);}

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SSIM Image Comparison

By default, image comparison is byte-exact. To tolerate minor rendering differences (anti-aliasing, font hinting, subpixel rendering), enable SSIM (Structural Similarity Index) comparison by passing a threshold to Initialize:

[ModuleInitializer]publicstaticvoidInit()=>VerifyImageSharp.Initialize(ssimThreshold:0.999);

SSIM returns a value between 0.0 (completely different) and 1.0 (identical). Images with an SSIM at or above the threshold are considered equal. Recommended thresholds:

• 0.999 — tolerates anti-aliasing and subpixel rendering differences
• 0.995 — tolerates minor font/layout shifts across OS versions
• 0.99 — tolerates moderate rendering variation

Per-test threshold

Override the global threshold for a specific test:

[Test]publicTaskVerifyImageWithSsimThreshold(){varimage=newImage<Rgba32>(11,11){[5,5]=Color.ParseHex("#0000FF").ToPixel<Rgba32>()};returnVerify(image).SsimThreshold(0.95);}

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Direct SSIM calculation

The SsimComparer class can also be used directly to get the raw SSIM value:

doublessim=SsimComparer.Calculate(receivedStream,verifiedStream);

File Samples

http://file-examples.com/

Icon

Swirl designed by BÖCK, RU from The Noun Project.