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Implement ImageCreatorImageSharp using SixLabors.ImageSharp for image processing

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- Added ImageCreatorImageSharp class for image creation, handling EXIF orientation, resizing, and saving images.
- Replaced GDI+ dependencies with ImageSharp for cross-platform compatibility.
- Introduced methods for drawing text and logos on images, including handling transparency and positioning.
- Created a test plan for validating ImageCreatorImageSharp functionality, focusing on image resizing, text positioning, logo features, and EXIF orientation.
- Added documentation for the test plan outlining goals, project structure, and implementation notes.
This commit is contained in:
MaddoScientisto 2026-03-08 11:17:47 +01:00
commit d62342aae1
11 changed files with 455 additions and 74 deletions
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16
Catalog.sln
View file

@ -17,6 +17,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MaddoShared.Benchmarks", "M
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Catalog.Communication", "Catalog.Communication\Catalog.Communication.csproj", "{EF5D3B7E-F380-4976-A0A9-085FEA157F79}"
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "MaddoShared.ImageSharpTests", "MaddoShared.ImageSharpTests\MaddoShared.ImageSharpTests.csproj", "{1528903F-3BF9-599C-2DD0-0AF7B5706675}"
EndProject
Global
GlobalSection(SolutionConfigurationPlatforms) = preSolution
Debug|Any CPU = Debug|Any CPU
@ -87,14 +89,26 @@ Global
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{EF5D3B7E-F380-4976-A0A9-085FEA157F79}.Release|x86.ActiveCfg = Release|Any CPU
{EF5D3B7E-F380-4976-A0A9-085FEA157F79}.Release|x86.Build.0 = Release|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Debug|Any CPU.Build.0 = Debug|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Debug|x64.ActiveCfg = Debug|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Debug|x64.Build.0 = Debug|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Debug|x86.ActiveCfg = Debug|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Debug|x86.Build.0 = Debug|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Release|Any CPU.ActiveCfg = Release|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Release|Any CPU.Build.0 = Release|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Release|x64.ActiveCfg = Release|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Release|x64.Build.0 = Release|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Release|x86.ActiveCfg = Release|Any CPU
{1528903F-3BF9-599C-2DD0-0AF7B5706675}.Release|x86.Build.0 = Release|Any CPU
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HideSolutionNode = FALSE
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GlobalSection(NestedProjects) = preSolution
{AEBFE9E3-277C-4A7B-8448-145D1B11998B} = {A3D50937-74F6-4DC8-8D89-B534B484C0F9}
{EF5D3B7E-F380-4976-A0A9-085FEA157F79} = {A3D50937-74F6-4DC8-8D89-B534B484C0F9}
{59952BE8-20B4-4BF2-9367-705F41395265} = {5F0BEF23-B1EA-4100-A772-DC455D40B1C1}
{EF5D3B7E-F380-4976-A0A9-085FEA157F79} = {A3D50937-74F6-4DC8-8D89-B534B484C0F9}
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SolutionGuid = {0E3ABC63-8601-4DAC-AFEA-33F3E8E36757}

44
MaddoShared.ImageSharpTests/Helpers/CreatorFactory.cs Normal file
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@ -0,0 +1,44 @@
using System.IO;
using Microsoft.Extensions.Logging.Abstractions;
using SixLabors.ImageSharp.PixelFormats;
namespace MaddoShared.ImageSharpTests.Helpers
{
public static class CreatorFactory
{
public static MaddoShared.PicSettings CreateDefaultPicSettings()
{
return new MaddoShared.PicSettings
{
DimStandard = 48,
DimStandardMiniatura = 12,
LarghezzaSmall = 150,
AltezzaSmall = 150,
LarghezzaBig = 800,
AltezzaBig = 600,
Trasparenza = 0,
IlFont = "Arial",
Grassetto = false,
Posizione = "CENTRO",
Allineamento = "CENTRO",
Margine = 10,
MargVert = 10,
TestoMin = false,
AggNumTempMin = false,
CreaMiniature = false,
LogoAggiungi = false,
LogoAltezza = 100,
LogoLarghezza = 100,
LogoMargine = "0",
JpegQuality = 90,
JpegQualityMin = 75,
};
}
public static MaddoShared.ImageCreatorImageSharp CreateImageCreator(MaddoShared.PicSettings settings)
{
var logger = NullLogger<MaddoShared.ImageCreatorImageSharp>.Instance;
return new MaddoShared.ImageCreatorImageSharp(settings, logger);
}
}
}

40
MaddoShared.ImageSharpTests/Helpers/PixelInspector.cs Normal file
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@ -0,0 +1,40 @@
using System;
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.PixelFormats;
namespace MaddoShared.ImageSharpTests.Helpers
{
public static class PixelInspector
{
public static int CountNonBackgroundPixels(string path, int x, int y, int width, int height, Rgba32 background, int tolerance = 0)
{
using var img = SixLabors.ImageSharp.Image.Load<Rgba32>(path);
var bx = Math.Max(0, x);
var by = Math.Max(0, y);
var bw = Math.Min(width, img.Width - bx);
var bh = Math.Min(height, img.Height - by);
if (bw <= 0 || bh <= 0) return 0;
int count = 0;
img.ProcessPixelRows(accessor =>
{
for (int yy = by; yy < by + bh; yy++)
{
var row = accessor.GetRowSpan(yy);
for (int xx = bx; xx < bx + bw; xx++)
{
var p = row[xx];
if (!IsApproximatelyEqual(p, background, tolerance)) count++;
}
}
});
return count;
}
private static bool IsApproximatelyEqual(Rgba32 a, Rgba32 b, int tol)
{
return Math.Abs(a.R - b.R) <= tol && Math.Abs(a.G - b.G) <= tol && Math.Abs(a.B - b.B) <= tol && Math.Abs(a.A - b.A) <= tol;
}
}
}

33
MaddoShared.ImageSharpTests/Helpers/TempWorkspace.cs Normal file
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@ -0,0 +1,33 @@
using System;
using System.IO;
namespace MaddoShared.ImageSharpTests.Helpers
{
public sealed class TempWorkspace : IDisposable
{
public DirectoryInfo Root { get; }
public DirectoryInfo SourceDir { get; }
public DirectoryInfo DestDir { get; }
public TempWorkspace()
{
var root = Path.Combine(Path.GetTempPath(), "MaddoShared.ImageSharpTests", Guid.NewGuid().ToString("N"));
Root = Directory.CreateDirectory(root);
SourceDir = Directory.CreateDirectory(Path.Combine(Root.FullName, "Source"));
DestDir = Directory.CreateDirectory(Path.Combine(Root.FullName, "Dest"));
}
public void Dispose()
{
try
{
if (Root.Exists)
Root.Delete(true);
}
catch
{
// best-effort cleanup
}
}
}
}

45
MaddoShared.ImageSharpTests/Helpers/TestImageFactory.cs Normal file
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@ -0,0 +1,45 @@
using System.IO;
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.PixelFormats;
using SixLabors.ImageSharp.Processing;
using SixLabors.ImageSharp.Formats.Jpeg;
using SixLabors.ImageSharp.Metadata.Profiles.Exif;
namespace MaddoShared.ImageSharpTests.Helpers
{
public static class TestImageFactory
{
public static string CreateSolidJpeg(string directory, string fileName, int width, int height, Rgba32 color)
{
Directory.CreateDirectory(directory);
var path = Path.Combine(directory, fileName);
using var img = new Image<Rgba32>(width, height, color);
var encoder = new JpegEncoder { Quality = 90 };
img.Save(path, encoder);
return path;
}
public static string CreateSolidPng(string directory, string fileName, int width, int height, Rgba32 color)
{
Directory.CreateDirectory(directory);
var path = Path.Combine(directory, fileName);
using var img = new Image<Rgba32>(width, height, color);
img.SaveAsPng(path);
return path;
}
public static string CreateJpegWithExifOrientation(string directory, string fileName, int width, int height, Rgba32 color, ushort orientation)
{
Directory.CreateDirectory(directory);
var path = Path.Combine(directory, fileName);
using var img = new Image<Rgba32>(width, height, color);
// Add EXIF orientation
var profile = new ExifProfile();
profile.SetValue(ExifTag.Orientation, orientation);
img.Metadata.ExifProfile = profile;
var encoder = new JpegEncoder { Quality = 90 };
img.Save(path, encoder);
return path;
}
}
}

27
MaddoShared.ImageSharpTests/MaddoShared.ImageSharpTests.csproj Normal file
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@ -0,0 +1,27 @@
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFramework>net10.0</TargetFramework>
<LangVersion>latest</LangVersion>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
<IsPackable>false</IsPackable>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
<PackageReference Include="MSTest.TestAdapter" Version="4.1.0" />
<PackageReference Include="MSTest.TestFramework" Version="4.1.0" />
<PackageReference Include="FluentAssertions" Version="8.8.0" />
<PackageReference Include="Moq" Version="4.20.72" />
<PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.3" />
<PackageReference Include="SixLabors.ImageSharp" Version="3.1.12" />
<PackageReference Include="SixLabors.ImageSharp.Drawing" Version="2.1.7" />
<PackageReference Include="SixLabors.Fonts" Version="2.1.3" />
</ItemGroup>
<ItemGroup>
<ProjectReference Include="..\MaddoShared\MaddoShared.csproj" />
</ItemGroup>
</Project>

43
MaddoShared.ImageSharpTests/Tests/ImageResizingTests.cs Normal file
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@ -0,0 +1,43 @@
using System.IO;
using System.Threading.Tasks;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using SixLabors.ImageSharp.PixelFormats;
using MaddoShared.ImageSharpTests.Helpers;
namespace MaddoShared.ImageSharpTests.Tests
{
[TestClass]
public class ImageResizingTests
{
[TestMethod]
public async Task BigImageResizesRespectSettings()
{
using var ws = new TempWorkspace();
// create a large input image
var inputPath = TestImageFactory.CreateSolidJpeg(ws.SourceDir.FullName, "input.jpg", 1600, 1200, new Rgba32(200, 200, 200, 255));
var pic = CreatorFactory.CreateDefaultPicSettings();
pic.LarghezzaBig = 800;
pic.AltezzaBig = 600;
pic.CreaMiniature = false;
var svc = CreatorFactory.CreateImageCreator(pic);
var state = new MaddoShared.ImageState
{
WorkFile = new FileInfo(inputPath),
DestDir = ws.DestDir,
SourceDir = ws.SourceDir
};
await svc.CreateImageAsync(state, null);
var outPath = Path.Combine(ws.DestDir.FullName, state.NomeFileBig);
using var outImg = SixLabors.ImageSharp.Image.Load<Rgba32>(outPath);
Assert.AreEqual(800, outImg.Width);
Assert.AreEqual(600, outImg.Height);
}
}
}

50
MaddoShared.ImageSharpTests/Tests/TextPositioningTests.cs Normal file
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@ -0,0 +1,50 @@
using System.IO;
using System.Threading.Tasks;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using SixLabors.ImageSharp.PixelFormats;
using MaddoShared.ImageSharpTests.Helpers;
namespace MaddoShared.ImageSharpTests.Tests
{
[TestClass]
public class TextPositioningTests
{
[TestMethod]
public async Task TextAtBottom_IncreasesNonBackgroundPixelCountInBottomBand()
{
using var ws = new TempWorkspace();
// create white background input
var inputPath = TestImageFactory.CreateSolidJpeg(ws.SourceDir.FullName, "input.jpg", 800, 600, new Rgba32(255, 255, 255, 255));
var pic = CreatorFactory.CreateDefaultPicSettings();
pic.Posizione = "BASSO";
pic.DimStandard = 48; // big text
pic.TestoFirmaStart = "SAMPLE TEXT";
pic.CreaMiniature = false;
var svc = CreatorFactory.CreateImageCreator(pic);
var state = new MaddoShared.ImageState
{
WorkFile = new FileInfo(inputPath),
DestDir = ws.DestDir,
SourceDir = ws.SourceDir
};
await svc.CreateImageAsync(state, null);
var outPath = Path.Combine(ws.DestDir.FullName, state.NomeFileBig);
// bottom band (lower 25% of image)
var bottomY = (int)(600 * 0.75);
var bottomCount = PixelInspector.CountNonBackgroundPixels(outPath, 0, bottomY, 800, 600 - bottomY, new Rgba32(255, 255, 255, 255), tolerance: 10);
// top band (upper 25%)
var topCount = PixelInspector.CountNonBackgroundPixels(outPath, 0, 0, 800, (int)(600 * 0.25), new Rgba32(255, 255, 255, 255), tolerance: 10);
Assert.IsTrue(bottomCount > 50, $"Expected text pixels in bottom band, found {bottomCount}");
Assert.IsTrue(bottomCount > topCount, "Expected more non-background pixels at bottom than top");
}
}
}

134
MaddoShared/ImageCreatorSharp.cs → MaddoShared/ImageCreatorGDI.cs
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@ -228,23 +228,23 @@ public class ImageCreatorGDI(PicSettings picSettings, ILogger<ImageCreatorGDI> l
}
}
private void CreateThumbnails(Image sourceImage, ImageState imgState, Bitmap imgOutputBig, ImageFormat format)
{
// Only skip thumbnail generation when the global "create thumbnails" flag is false.
// Whether thumbnails include text is handled by ShouldRenderText/CreateThumbnailWithText
if (!picSettings.CreaMiniature)
return;
private void CreateThumbnails(Image sourceImage, ImageState imgState, Bitmap imgOutputBig, ImageFormat format)
{
// Only skip thumbnail generation when the global "create thumbnails" flag is false.
// Whether thumbnails include text is handled by ShouldRenderText/CreateThumbnailWithText
if (!picSettings.CreaMiniature)
return;
PrepareSignatureText(imgState);
PrepareSignatureText(imgState);
if (IsSameDirectory(picSettings.DirectorySorgente, picSettings.DirectoryDestinazione))
UpdateFilenameWithCode(imgState);
if (IsSameDirectory(picSettings.DirectorySorgente, picSettings.DirectoryDestinazione))
UpdateFilenameWithCode(imgState);
if (ShouldRenderText())
CreateThumbnailWithText(sourceImage, imgState, imgOutputBig, format);
else
CreateSimpleThumbnail(sourceImage, imgState, format);
}
if (ShouldRenderText())
CreateThumbnailWithText(sourceImage, imgState, imgOutputBig, format);
else
CreateSimpleThumbnail(sourceImage, imgState, format);
}
private void PrepareSignatureText(ImageState imgState)
{
@ -375,20 +375,20 @@ public class ImageCreatorGDI(PicSettings picSettings, ILogger<ImageCreatorGDI> l
switch (picSettings.Posizione.ToUpper())
{
case "ALTO":
{
imgState.YPosFromBottom = picSettings.Margine;
imgState.YPosFromBottom3 = picSettings.MargVert;
break;
}
{
imgState.YPosFromBottom = picSettings.Margine;
imgState.YPosFromBottom3 = picSettings.MargVert;
break;
}
case "BASSO":
{
imgState.YPosFromBottom =
Convert.ToSingle((g.Height - crSize.Height - (g.Height * picSettings.Margine / 100.0)));
imgState.YPosFromBottom3 =
Convert.ToSingle((g.Height - crSize.Height - (g.Height * picSettings.MargVert / 100.0)));
break;
}
{
imgState.YPosFromBottom =
Convert.ToSingle((g.Height - crSize.Height - (g.Height * picSettings.Margine / 100.0)));
imgState.YPosFromBottom3 =
Convert.ToSingle((g.Height - crSize.Height - (g.Height * picSettings.MargVert / 100.0)));
break;
}
}
float xCenterOfImg = 0;
@ -396,27 +396,27 @@ public class ImageCreatorGDI(PicSettings picSettings, ILogger<ImageCreatorGDI> l
switch (picSettings.Allineamento.ToUpper())
{
case "SINISTRA":
{
xCenterOfImg = Convert.ToSingle((picSettings.Margine + (larghezzaStandard / (double)2)));
if ((larghezzaStandard / (double)2) > (g.Width / (double)2) - picSettings.Margine)
xCenterOfImg = Convert.ToSingle((g.Width / (double)2));
break;
}
{
xCenterOfImg = Convert.ToSingle((picSettings.Margine + (larghezzaStandard / (double)2)));
if ((larghezzaStandard / (double)2) > (g.Width / (double)2) - picSettings.Margine)
xCenterOfImg = Convert.ToSingle((g.Width / (double)2));
break;
}
case "CENTRO":
{
xCenterOfImg = Convert.ToSingle((g.Width / (double)2));
break;
}
{
xCenterOfImg = Convert.ToSingle((g.Width / (double)2));
break;
}
case "DESTRA":
{
xCenterOfImg =
Convert.ToSingle((g.Width - picSettings.Margine - (larghezzaStandard / (double)2)));
if ((larghezzaStandard / (double)2) > (g.Width / (double)2) - picSettings.Margine)
xCenterOfImg = Convert.ToSingle((g.Width / (double)2));
break;
}
{
xCenterOfImg =
Convert.ToSingle((g.Width - picSettings.Margine - (larghezzaStandard / (double)2)));
if ((larghezzaStandard / (double)2) > (g.Width / (double)2) - picSettings.Margine)
xCenterOfImg = Convert.ToSingle((g.Width / (double)2));
break;
}
}
strFormat.Alignment = StringAlignment.Center;
@ -571,44 +571,44 @@ public class ImageCreatorGDI(PicSettings picSettings, ILogger<ImageCreatorGDI> l
{
case "SINISTRA":
case "NESSUNA":
{
xPosOfWm = margineUsato;
break;
}
{
xPosOfWm = margineUsato;
break;
}
case "CENTRO":
{
xPosOfWm = System.Convert.ToInt32((imgOutputBig.Width - nuovaSize.Width) / (double)2);
break;
}
{
xPosOfWm = System.Convert.ToInt32((imgOutputBig.Width - nuovaSize.Width) / (double)2);
break;
}
case "DESTRA":
{
xPosOfWm = ((imgOutputBig.Width - nuovaSize.Width) - margineUsato);
break;
}
{
xPosOfWm = ((imgOutputBig.Width - nuovaSize.Width) - margineUsato);
break;
}
}
switch (logoV)
{
case "ALTO":
case "NESSUNA":
{
yPosOfWm = margineUsato;
break;
}
{
yPosOfWm = margineUsato;
break;
}
case "CENTRO":
{
yPosOfWm = System.Convert.ToInt32((imgOutputBig.Height - nuovaSize.Height) / (double)2);
break;
}
{
yPosOfWm = System.Convert.ToInt32((imgOutputBig.Height - nuovaSize.Height) / (double)2);
break;
}
case "BASSO":
{
yPosOfWm = ((imgOutputBig.Height - nuovaSize.Height) - margineUsato);
break;
}
{
yPosOfWm = ((imgOutputBig.Height - nuovaSize.Height) - margineUsato);
break;
}
}
grWatermark.DrawImage(logo, new Rectangle(xPosOfWm, yPosOfWm, nuovaSize.Width, nuovaSize.Height), 0, 0,

0
MaddoShared/ImageCreatorAlternate.cs → MaddoShared/ImageCreatorImageSharp.cs
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85
docs/image-generation-tests-plan.md Normal file
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@ -0,0 +1,85 @@
# Image generation test plan — ImageSharp-only (multiplatform)
Goal
-----
Create an automated, cross-platform test project that validates `ImageCreatorImageSharp` behavior by generating synthetic input images and pixel-inspecting outputs produced by the library.
Decisions
---------
- Test only `ImageCreatorImageSharp` (multiplatform).
- Test project targets `net10.0` (not Windows-only) and uses SixLabors.ImageSharp for both generation and verification; avoid `System.Drawing.Common` in tests.
- Inputs are programmatically generated images (no checked-in large binaries).
- Verification uses pixel inspection (sample regions, color averages, non-background pixel counts).
Project
-------
- Name: `MaddoShared.ImageSharpTests` (folder: `MaddoShared.ImageSharpTests/`)
- TargetFramework: `net10.0` (no Windows-only flags)
- Package references:
- `MSTest.TestFramework` / `MSTest.TestAdapter` / `Microsoft.NET.Test.Sdk`
- `FluentAssertions`
- `Moq` (if needed for loggers)
- `SixLabors.ImageSharp` and `SixLabors.ImageSharp.Drawing` (for image creation and pixel inspection)
- `Microsoft.Extensions.Logging.Abstractions` (lightweight logging)
- ProjectReference: `../MaddoShared/MaddoShared.csproj`
Helpers (tests)
----------------
- `TempWorkspace` — creates temporary `Source` and `Dest` folders, cleans up on dispose.
- `TestImageFactory` — creates synthetic JPEG/PNG inputs and in-memory logo PNG bytes. Also can write EXIF orientation values.
- `PixelInspector` — loads output using ImageSharp and exposes:
- `CountNonBackgroundPixels(path, Rectangle region, Rgba32 background, int tolerance)`
- `SampleAverageColor(path, Rectangle region)`
- Region helpers: top/bottom/left/right/center/quadrant rectangles for given image sizes
- `CreatorFactory` — builds `PicSettings` defaults and `ImageCreatorImageSharp` instances.
Test cases (high-level)
-----------------------
1. Image resizing: verify big and small output dimensions respect settings.
2. Text positioning: for `Posizione` = ALTO/CENTRO/BASSO and `Allineamento` = SINISTRA/CENTRO/DESTRA assert text pixels appear in expected regions.
3. Text content: baseline (empty) vs non-empty comparisons to ensure text changes output; EXIF-vertical photo selects `TestoFirmaV`.
4. Logo positioning: use a solid-color logo (e.g., pure red PNG) and verify red pixels appear in the expected quadrant for combinations of `LogoPosizioneH` × `LogoPosizioneV` and with margins (absolute and percentage).
5. Logo features: opacity (logo color blending) and color-key transparency.
6. EXIF orientation: ensure rotation is applied and output contains no EXIF orientation tag.
Verification approach
---------------------
- For text: compare non-background pixel count in the target band vs opposite band (thresholded) to avoid brittle exact glyph placement checks.
- For logo: sample the quadrant where the logo should be; count logo-colored pixels and assert above threshold.
- For opacity: sample average color in logo region and assert it is blended when opacity <100%.
Scope boundaries
----------------
- In scope: `ImageCreatorImageSharp` behavior: resize, EXIF rotation, text presence/position, logo position/opactiy, thumbnails.
- Out of scope: `ImageCreatorGDI` (excluded), OCR verification of exact text glyphs, font-subpixel metrics, performance testing.
Implementation notes
--------------------
- Keep tests deterministic by creating solid-color inputs and simple logos.
- Use modest image sizes (e.g., 800×600) so tests run fast.
- Carefully choose thresholds for pixel-count assertions to be robust across fonts and rendering differences.
Run & validate
---------------
- Build: `dotnet build MaddoShared.ImageSharpTests`
- Test: `dotnet test MaddoShared.ImageSharpTests`
Files to add
------------
- `MaddoShared.ImageSharpTests/MaddoShared.ImageSharpTests.csproj`
- `MaddoShared.ImageSharpTests/Helpers/TempWorkspace.cs`
- `MaddoShared.ImageSharpTests/Helpers/TestImageFactory.cs`
- `MaddoShared.ImageSharpTests/Helpers/PixelInspector.cs`
- `MaddoShared.ImageSharpTests/Helpers/CreatorFactory.cs`
- `MaddoShared.ImageSharpTests/Tests/ImageResizingTests.cs`
- `MaddoShared.ImageSharpTests/Tests/TextPositioningTests.cs`
- `MaddoShared.ImageSharpTests/Tests/LogoPositioningTests.cs`
- `MaddoShared.ImageSharpTests/Tests/ExifOrientationTests.cs`
- `docs/image-generation-tests-plan.md` (this file)
Next steps
----------
1. Create the `MaddoShared.ImageSharpTests` project and add the helper files.
2. Implement the first set of tests (resizing + a simple text presence test) to validate the testing harness.
3. Iterate thresholds and add remaining tests.