1020949-detecting blank pages of the extracted images in core platform

Pages/Blank-page-detection/.NET/Blank-page-detection.slnx

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+<Solution>
+  <Project Path="Blank-page-detection/Blank-page-detection.csproj" />
+</Solution>

Pages/Blank-page-detection/.NET/Blank-page-detection/Blank-page-detection.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0</TargetFramework>
+    <RootNamespace>Blank_page_detection</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Syncfusion.Pdf.Imaging.Net.Core" Version="*" />
+  </ItemGroup>
+
+</Project>

Pages/Blank-page-detection/.NET/Blank-page-detection/Program.cs

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+using SkiaSharp;
+using Syncfusion.Pdf;
+using Syncfusion.Pdf.Exporting;
+using Syncfusion.Pdf.Parsing;
+
+//Load the document
+PdfLoadedDocument loadedDocument = new PdfLoadedDocument(@"../../../Input.pdf");
+
+for (int i = 0; i < loadedDocument.Pages.Count; i++)
+{
+    PdfPageBase loadedPage = loadedDocument.Pages[i];
+
+    // 1. Extract text
+    string text = loadedPage.ExtractText();
+
+    if (!string.IsNullOrEmpty(text))
+    {
+        continue; // Page has text, so it's not blank
+    }
+
+    // 2. Extract images
+    PdfImageInfo[] imagesInfo = loadedPage.GetImagesInfo();
+
+    bool hasNonBlankImage = false;
+
+    foreach (PdfImageInfo imageInfo in imagesInfo)
+    {
+        using MemoryStream ms = new MemoryStream();
+        imageInfo.ImageStream.CopyTo(ms);
+        byte[] imageBytes = ms.ToArray();
+
+        if (!IsBlankImage(imageBytes))
+        {
+            hasNonBlankImage = true;
+            break;
+        }
+    }
+
+    // 3. Final blank-page detection based on image              
+    bool hasImages = imagesInfo.Length > 0;
+
+    if (!hasImages || !hasNonBlankImage)
+    {
+        Console.WriteLine($"Page {i + 1} is blank.");
+    }
+}
+
+loadedDocument.Close(true);
+static bool IsBlankImage(byte[] imageBytes, byte colorTolerance = 5)
+{
+    using var skData = SKData.CreateCopy(imageBytes);
+    using var skImage = SKImage.FromEncodedData(skData);
+    using var bitmap = SKBitmap.FromImage(skImage);
+
+    SKColor? referenceColor = null;
+
+    for (int y = 0; y < bitmap.Height; y++)
+    {
+        for (int x = 0; x < bitmap.Width; x++)
+        {
+            SKColor pixel = bitmap.GetPixel(x, y);
+
+            if (referenceColor == null)
+            {
+                referenceColor = pixel;
+                continue;
+            }
+
+            if (Math.Abs(pixel.Red - referenceColor.Value.Red) > colorTolerance ||
+                Math.Abs(pixel.Green - referenceColor.Value.Green) > colorTolerance ||
+                Math.Abs(pixel.Blue - referenceColor.Value.Blue) > colorTolerance ||
+                Math.Abs(pixel.Alpha - referenceColor.Value.Alpha) > colorTolerance)
+            {
+                return false; // Not blank
+            }
+        }
+    }
+
+    return true; // Image is blank
+}