---
title: "C# .NET blur image: Blur full image or a region | Nutrient .NET SDK"
canonical_url: "https://www.nutrient.io/guides/dotnet/editor/manipulation/blur/"
md_url: "https://www.nutrient.io/guides/dotnet/editor/manipulation/blur.md"
last_updated: "2026-05-20T07:45:28.971Z"
description: "Learn how to blur images programmatically in C# .NET using Nutrient .NET SDK. Apply blur effects for privacy or creative image editing."
---

# Blur images in C# .NET

Use one of the following methods to add the blur effect to images:

- [`FxBlur`](#standard-blur)

- [`FxGaussian`](#gaussian-blur)

For each of these methods, you can [apply the blur effect to a part of an image](#specifying-the-affected-area).

## Standard blur

For blurring an entire image, use the [`FxBlur`](https://www.nutrient.io/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~FxBlur.html) method. It only requires the image ID as its parameter.

To blur part of an image, refer to the [Specifying the Affected Area](#specifying-the-affected-area) section.

To blur an entire image, use the following code:

### C#

```csharp

using GdPictureImaging gdpictureImaging = new GdPictureImaging();
int imageID = gdpictureImaging.CreateGdPictureImageFromFile(@"C:\temp\source.jpg");
// Blur the entire image.
gdpictureImaging.FxBlur(imageID);
gdpictureImaging.SaveAsPNG(imageID, @"C:\temp\output.png");
gdpictureImaging.ReleaseGdPictureImage(imageID);

```

### VB.NET

```vb

Using gdpictureImaging As GdPictureImaging = New GdPictureImaging()
    Dim imageID As Integer = gdpictureImaging.CreateGdPictureImageFromFile("C:\temp\source.jpg")
    ' Blur the entire image.
    gdpictureImaging.FxBlur(imageID)
    gdpictureImaging.SaveAsPNG(imageID, "C:\temp\output.png")
    gdpictureImaging.ReleaseGdPictureImage(imageID)
End Using

```

#### Used methods

- [`CreateGdPictureImageFromFile`](/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~CreateGdPictureImageFromFile.html)

- [`FxBlur`]

- [`ReleaseGdPictureImage`](/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~ReleaseGdPictureImage.html)

- [`SaveAsPNG`](/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~SaveAsPNG.html)

#### Related topics

- [Load a file](/guides/dotnet/load-a-file.md)

- [Save a file](/guides/dotnet/save-a-file.md)

## Gaussian blur

To blur an entire image with a specific blur effect intensity, use the [`FxGaussian`](https://www.nutrient.io/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~FxGaussian.html) method. To define the blur intensity, use the `KernelSize` parameter. The higher the number, the more blurred an image becomes.

To blur part of an image, refer to the [Specifying the Affected Area](#specifying-the-affected-area) section.

To blur an entire image with the blur intensity set to 15, use the following code:

### C#

```csharp

using GdPictureImaging gdpictureImaging = new GdPictureImaging();
int imageID = gdpictureImaging.CreateGdPictureImageFromFile(@"C:\temp\source.jpg");
int kernel = 15;
// Blur the entire image with the kernel size set to 15.
gdpictureImaging.FxGaussian(imageID, kernel);
gdpictureImaging.SaveAsPNG(imageID, @"C:\temp\output.png");
gdpictureImaging.ReleaseGdPictureImage(imageID);

```

### VB.NET

```vb

Using gdpictureImaging As GdPictureImaging = New GdPictureImaging()
    Dim imageID As Integer = gdpictureImaging.CreateGdPictureImageFromFile("C:\temp\source.jpg")
    Dim kernel = 15
    ' Blur the entire image with kernel size set to 15.
    gdpictureImaging.FxGaussian(imageID, kernel)
    gdpictureImaging.SaveAsPNG(imageID, "C:\temp\output.png")
    gdpictureImaging.ReleaseGdPictureImage(imageID)
End Using

```

#### Used methods

- [`CreateGdPictureImageFromFile`](/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~CreateGdPictureImageFromFile.html)

- [`FxGaussian`]

- [`ReleaseGdPictureImage`](/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~ReleaseGdPictureImage.html)

- [`SaveAsPNG`](/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~SaveAsPNG.html)

#### Related topics

- [Load a file](/guides/dotnet/load-a-file.md)

- [Save a file](/guides/dotnet/save-a-file.md)

## Specifying the affected area

When using the [`FxBlur`](#standard-blur) and [`FxGaussian`](#gaussian-blur) methods, you can specify the area you want to blur. Use the [`SetROI`](https://www.nutrient.io/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~SetROI.html) method, which takes the following parameters:

- The coordinates of the top-left corner of the affected area.

- The width of the affected area.

- The height of the affected area.

After applying the blur effect, remember to reset the selected area with the [`ResetROI`](https://www.nutrient.io/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~ResetROI.html) method.

The origin of the coordinate system is the top-left corner of the original image.

To blur an image area of 500×500 pixels with the top and left margins set to 100 pixels, use the following code:

### C#

```csharp

using GdPictureImaging gdpictureImaging = new GdPictureImaging();
int imageID = gdpictureImaging.CreateGdPictureImageFromFile(@"C:\temp\source.jpg");
// Set the affected area.
gdpictureImaging.SetROI(100, 100, 500, 500);
// Blur the affected area.
gdpictureImaging.FxBlur(imageID);
// Reset the affected area.
gdpictureImaging.ResetROI();
gdpictureImaging.SaveAsPNG(imageID, @"C:\temp\output.png");
gdpictureImaging.ReleaseGdPictureImage(imageID);

```

### VB.NET

```vb

Using gdpictureImaging As GdPictureImaging = New GdPictureImaging()
    Dim imageID As Integer = gdpictureImaging.CreateGdPictureImageFromFile("C:\temp\source.jpg")
    ' Set the affected area.
    gdpictureImaging.SetROI(100, 100, 500, 500)
    ' Blur the affected area.
    gdpictureImaging.FxBlur(imageID)
    ' Reset the affected area.
    gdpictureImaging.ResetROI()
    gdpictureImaging.SaveAsPNG(imageID, "C:\temp\output.png")
    gdpictureImaging.ReleaseGdPictureImage(imageID)
End Using

```

#### Used methods

- [`CreateGdPictureImageFromFile`](/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~CreateGdPictureImageFromFile.html)

- [`FxBlur`]

- [`ReleaseGdPictureImage`](/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~ReleaseGdPictureImage.html)

- [`ResetROI`]

- [`SaveAsPNG`](/api/gdpicture/GdPicture.NET.14~GdPicture14.GdPictureImaging~SaveAsPNG.html)

- [`SetROI`]

#### Related topics

- [Load a file](/guides/dotnet/load-a-file.md)

- [Save a file](/guides/dotnet/save-a-file.md)
---

## Related pages

- [Image filters using C# .NET](/guides/dotnet/editor/manipulation/filters.md)
- [Set image or PDF colors in C#](/guides/dotnet/editor/manipulation/colors.md)
- [Crop images in C# .NET](/guides/dotnet/editor/manipulation/crop.md)
- [PDF and image manipulation in C# .NET](/guides/dotnet/editor/manipulation.md)
- [Remove pages from PDFs in C#](/guides/dotnet/editor/manipulation/remove-page.md)
- [Replace colors in an image](/guides/dotnet/editor/manipulation/replace-colors-from-image.md)
- [Rotate images and PDFs in C# .NET](/guides/dotnet/editor/manipulation/rotate.md)
- [Move or copy PDF pages and TIFF images in C#](/guides/dotnet/editor/manipulation/move-or-copy-page.md)
- [Extract pages from a PDF in C#](/guides/dotnet/editor/manipulation/extract.md)