---
title: "Convert a PDF to TIFF in C#"
url: https://recursiveai.org/oneimage/cookbook/pdf-to-tiff/
description: "Convert a PDF to a multipage TIFF in C# with pure .NET code: every page or a range, 300 dpi, gray or black and white for archives and fax. Runnable code with OneImage.Pdf."
version: "1.10.4"
---

# Convert a PDF to TIFF in C#

Register OneImage’s PDF format, load the PDF and save it with a `.tif` extension: every page becomes a page of one multipage TIFF. Drawing, encoding and compression are managed .NET code, with no Ghostscript to deploy. The program below converts the IRS Form W-9, a public six-page PDF, at 300 dpi in color, gray and black and white.

```shell
dotnet new console -o PdfToTiff && cd PdfToTiff
dotnet add package RecursiveAI.OneImage.Pdf --version 1.10.4
curl -LO https://www.irs.gov/pub/irs-pdf/fw9.pdf
```

OneImage needs the .NET 10 SDK. Put this in `Program.cs` and run `dotnet run`:

```csharp
using OneImage;
using OneImage.Pdf;

var options = new LoadOptions
{
    Configuration = new ImageConfiguration()
        .Add(new PdfFormat(new PdfRenderOptions { Dpi = 300 })),
};

// Pages are drawn on opaque white, so the alpha channel can go.
Image pdf = Image.Load("fw9.pdf", options).RemoveAlpha();

Image gray = pdf.Grayscale(toGrayFormat: true);

pdf.Save("fw9.tif");                          // color, LZW
gray.Save("fw9-gray.tif");                    // 8-bit gray
gray.Threshold(0.5).Save("fw9-bw.tif");       // black and white

foreach (string file in new[] { "fw9.tif", "fw9-gray.tif", "fw9-bw.tif" })
{
    ImageInfo info = Image.Identify(file);
    long kb = new FileInfo(file).Length / 1024;
    string size = $"{info.Width}x{info.Height}";
    Console.WriteLine($"{file}: {info.Frames.Count} pages, {size}, "
                    + $"{info.Frames[0].Format}, {kb:N0} KB");
}
```

```text
fw9.tif: 6 pages, 2550x3300, Rgb/U8/None, 10,905 KB
fw9-gray.tif: 6 pages, 2550x3300, Gray/U8/None, 6,962 KB
fw9-bw.tif: 6 pages, 2550x3300, Gray/U8/None, 1,401 KB
```

At 300 dpi a US Letter page is 2550×3300 pixels. Saving the whole document writes every page, because TIFF holds several. `RemoveAlpha()` keeps the alpha channel PDF pages are drawn with out of the file. `Threshold(0.5)` turns every pixel white or black; raise it to keep fainter lines, or use `AdaptiveThreshold()` for unevenly lit scans ([grayscale and black and white](https://recursiveai.org/oneimage/cookbook/convert-to-grayscale/)).

## A range of pages, or one file per page

```csharp
using OneImage;
using OneImage.Pdf;

// Pages 2 to 4: FirstPage counts from 0.
var range = new LoadOptions
{
    Configuration = new ImageConfiguration().Add(new PdfFormat(
        new PdfRenderOptions { Dpi = 200, FirstPage = 1, PageCount = 3 })),
};
Image pages = Image.Load("fw9.pdf", range).RemoveAlpha();
pages.Save("fw9-pages-2-4.tif");
int count = Image.Identify("fw9-pages-2-4.tif").Frames.Count;
Console.WriteLine($"fw9-pages-2-4.tif: {count} pages");

// One single-page TIFF per page.
for (int i = 0; i < pages.FrameCount; i++)
{
    pages.Frames[i].ToImage().Save($"page-{i + 2}.tif");
    Console.WriteLine($"page-{i + 2}.tif");
}
```

```text
fw9-pages-2-4.tif: 3 pages
page-2.tif
page-3.tif
page-4.tif
```

Pages outside the range aren’t drawn at all.

## Compression

TIFF pages are LZW-compressed by default. Pass `new SaveOptions { EncoderOptions = new TiffEncoderOptions { Compression = TiffCompression.Deflate } }` for Deflate, or `None` or `PackBits`.

## Limits

- **No 1-bit or CCITT Group 4 output.** Black and white pages are stored as 8-bit gray with only two values, compressed with LZW, Deflate or PackBits. OneImage reads fax (CCITT G3 and G4) TIFFs but doesn’t write them; if a fax system requires G4, convert with another tool.
- **Large documents are built in one go.** Saving to a `MemoryStream` holds the whole TIFF in memory; for long documents write to a file or convert a range at a time. At most 1,000 pages load by default.
- **It renders pixels only:** text in the TIFF isn’t searchable.

To render pages as PNG or JPG instead, see [Convert a PDF to an image](https://recursiveai.org/oneimage/cookbook/pdf-to-image/); to split a TIFF again, [Split a multipage TIFF](https://recursiveai.org/oneimage/cookbook/split-multipage-tiff/).