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Merge pull request #493 from telerik/new-kb-convert-color-pdf-to-black-and-white-telerik-document-processing-e355c1c1edb14e86b52a7c951b5a84ec
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‎knowledge-base/convert-color-pdf-to-black-and-white-telerik-document-processing.md‎

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---
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title: Converting Colored PDF Documents to GrayScale with Telerik Document Processing
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description: Learn how to use Telerik Document Processing libraries to convert color PDF reports into black and white format.
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type: how-to
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page_title: How to Convert Color PDF Reports to Black & White Using Telerik Document Processing
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slug: convert-color-pdf-to-black-and-white-telerik-document-processing
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tags: document, processing, pdf, conversion, black, white, gray, image, convert
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res_type: kb
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ticketid: 1675661
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---
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## Environment
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| Version | Product | Author |
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| ---- | ---- | ---- |
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| 2024.4.1106| RadPdfProcessing |[Desislava Yordanova](https://www.telerik.com/blogs/author/desislava-yordanova)|
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## Description
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This article shows a sample approach how to convert a **colored** PDF document to a **grayscale** one with [RadPdfProcessing]({%slug radpdfprocessing-overview%}).
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![Converting Colored PDF Documents to GrayScale](images/convert-grascale-pdf.png)
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## Solution
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To convert a colored PDF file to black and white using Telerik Document Processing, follow the steps below:
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1. Use the [RadPdfProcessing]({%slug radpdfprocessing-overview%}) library to import the PDF file.
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2. Iterate through the content of the PDF file, including [Path]({%slug radpdfprocessing-model-path%}), [TextFragment]({%slug radpdfprocessing-model-textfragment%}), and [Image]({%slug radpdfprocessing-model-image%}) instances.
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3. Modify the colors to grayscale and export the processed file as a new PDF document.
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Here is a complete code snippet that demonstrates how to achieve this conversion:
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```csharp
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static void Main(string[] args)
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{
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PdfFormatProvider provider = new PdfFormatProvider();
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RadFixedDocument document = provider.Import(System.IO.File.ReadAllBytes(filePath));
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foreach (RadFixedPage page in document.Pages)
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{
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foreach (ContentElementBase element in page.Content)
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{
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MakeGrayscale(element);
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}
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}
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string resultFile = "grayscale.pdf";
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if (System.IO.File.Exists(resultFile))
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{
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System.IO.File.Delete(resultFile);
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}
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System.IO.File.WriteAllBytes(resultFile, provider.Export(document, TimeSpan.FromSeconds(10)));
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Process.Start(resultFile);
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}
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private static void MakeGrayscale(ContentElementBase element)
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{
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TextFragment text = element as TextFragment;
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if (text != null)
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{
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text.Stroke = MakeGrayscale(text.Stroke);
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text.Fill = MakeGrayscale(text.Fill);
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}
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if (element is Path path)
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{
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path.Stroke = MakeGrayscale(path.Stroke);
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path.Fill = MakeGrayscale(path.Fill);
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}
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Image image = element as Image;
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if (image != null)
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{
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BitmapSource originalImage = image.ImageSource.GetBitmapSource();
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BitmapSource grayscaleImage = MakeGrayscale(originalImage);
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image.ImageSource = new Telerik.Windows.Documents.Fixed.Model.Resources.ImageSource(grayscaleImage);
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}
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}
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private static BitmapSource MakeGrayscale(BitmapSource source)
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{
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byte?[,] intensities = GetPixelsIntensity(source);
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BitmapSource grayscaleSource = CreateImageFromGrayPixels(intensities);
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return grayscaleSource;
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}
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private static ColorBase MakeGrayscale(ColorBase color)
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{
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RgbColor rgb = (RgbColor)color;
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byte gray = GetGrayIntensity(rgb.R, rgb.G, rgb.G);
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return new RgbColor(rgb.A, gray, gray, gray);
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}
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private static BitmapSource CreateImageFromGrayPixels(byte?[,] pixels)
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{
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double dpi = 96;
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int height = pixels.GetLength(0);
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int width = pixels.GetLength(1);
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byte[] pixelData = new byte[width * height];
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for (int y = 0; y < height; ++y)
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{
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int yIndex = y * width;
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for (int x = 0; x < width; ++x)
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{
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pixelData[x + yIndex] = pixels[y, x] ?? 255;
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}
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}
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BitmapSource bmpSource = BitmapSource.Create(width, height, dpi, dpi, PixelFormats.Gray8, null, pixelData, width);
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return bmpSource;
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}
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private static byte?[,] GetPixelsIntensity(BitmapSource bitmapSource)
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{
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int width = bitmapSource.PixelWidth;
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int height = bitmapSource.PixelHeight;
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byte?[,] intensities = new byte?[height, width];
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int[] pixels = GetPixels(bitmapSource);
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int pixelIndex = 0;
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for (int i = 0; i < height; i++)
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{
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for (int j = 0; j < width; j++)
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{
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byte a, r, g, b;
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GetComponentsFromPixel(pixels[pixelIndex++], out a, out r, out g, out b);
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byte? intensity;
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if (a == 0)
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{
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intensity = null;
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}
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else
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{
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intensity = (byte)((a / 255.0) * GetGrayIntensity(r, g, b));
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intensity = intensity.Value < 255 ? ((byte)(intensity.Value + 1)) : intensity.Value;
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}
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intensities[i, j] = intensity;
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}
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}
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return intensities;
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}
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private static void GetComponentsFromPixel(int pixel, out byte a, out byte r, out byte g, out byte b)
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{
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b = (byte)(pixel & 0xFF);
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g = (byte)((pixel >> 8) & 0xFF);
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r = (byte)((pixel >> 16) & 0xFF);
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a = (byte)((pixel >> 24) & 0xFF);
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}
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private static int[] GetPixels(BitmapSource source)
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{
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int[] pixels = new int[source.PixelWidth * source.PixelHeight];
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if (source.Format == PixelFormats.Bgr32 || source.Format == PixelFormats.Bgra32 || source.Format == PixelFormats.Pbgra32)
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{
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checked
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{
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source.CopyPixels(pixels, source.PixelWidth * 4, 0);
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}
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}
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else if (source.Format == PixelFormats.Indexed8)
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{
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byte[] indices = new byte[source.PixelWidth * source.PixelHeight];
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source.CopyPixels(indices, source.PixelWidth, 0);
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for (int i = 0; i < indices.Length; ++i)
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{
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Color c = source.Palette.Colors[indices[i]];
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pixels[i] = (c.A << 24) | (c.R << 16) | (c.G << 8) | (c.B << 0);
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}
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}
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else
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{
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FormatConvertedBitmap converted = new FormatConvertedBitmap(source, PixelFormats.Bgra32, null, 0);
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converted.CopyPixels(pixels, source.PixelWidth * 4, 0);
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}
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return pixels;
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}
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private static byte GetGrayIntensity(byte r, byte g, byte b)
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{
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return (byte)(0.2126 * r + 0.7152 * g + 0.0722 * b);
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}
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```
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Ensure to adjust the `MakeGrayscale` methods for `ColorBase`, `Path`, and `Image` according to your specific needs. This sample demonstrates the basic approach to converting document elements to grayscale but might require adjustments for complex scenarios or specific color processing requirements.
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## See Also
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- [RadPdfProcessing Overview]({%slug radpdfprocessing-overview%})
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- [How to Generate a PDF Document from Images with FixedContentEditor]({%slug pdf-from-images-with-fixedcontenteditor%})
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- [How to Generate a PDF Document from Images with RadFixedDocumentEditor]({%slug pdf-from-images-with-radfixeddocumenteditor%})

‎knowledge-base/images/convert-grascale-pdf.png‎

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‎knowledge-base/pdf-from-images-with-fixedcontenteditor.md‎

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- [RadFixedPage]({%slug radpdfprocessing-model-radfixedpage%})
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- [Position]({%slug radpdfprocessing-concepts-position%})
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- [PdfFormatProvider]({%slug radpdfprocessing-formats-and-conversion-pdf-pdfformatprovider%})
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- [RadPdfProcessing Documentation](https://docs.telerik.com/devtools/document-processing/libraries/radpdfprocessing/overview)
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- [RadPdfProcessing](https://docs.telerik.com/devtools/document-processing/libraries/radpdfprocessing/overview)
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- [Converting Colored PDF Documents to GrayScale with Telerik Document Processing]({%slug convert-color-pdf-to-black-and-white-telerik-document-processing%})

‎knowledge-base/pdf-from-images-with-radfixeddocumenteditor.md‎

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- [RadFixedDocumentEditor]({%slug radpdfprocessing-editing-radfixeddocumenteditor%})
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- [PdfFormatProvider]({%slug radpdfprocessing-formats-and-conversion-pdf-pdfformatprovider%})
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- [RadPdfProcessing]({%slug radpdfprocessing-overview%})
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- [Converting Colored PDF Documents to GrayScale with Telerik Document Processing]({%slug convert-color-pdf-to-black-and-white-telerik-document-processing%})

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