Image Manipulation

ABP provides services to compress and resize images and implements these services with popular ImageSharp and Magick.NET libraries. You can use these services in your reusable modules, libraries and applications, so you don't depend on a specific imaging library.

The image resizer/compressor system is designed to be extensible. You can implement your own image resizer/compressor contributor and use it in your application.

Installation

You can add this package to your application by either using the ABP CLI or manually installing it. Using the ABP CLI is the recommended approach.

Using the ABP CLI

Open a command line terminal in the folder of your project (.csproj file) and type the following command:

abp add-package Volo.Abp.Imaging.Abstractions

Manual Installation

If you want to manually install;

1. Add the Volo.Abp.Imaging.Abstractions NuGet package to your project:

Install-Package Volo.Abp.Imaging.Abstractions

2. Add the AbpImagingAbstractionsModule to the dependency list of your module:

[DependsOn(
    //...other dependencies
    typeof(AbpImagingAbstractionsModule) //Add the new module dependency
    )]
public class YourModule : AbpModule
{
}

Providers

ABP provides two image resizer/compressor implementations out of the box:

• Magick.NET
• ImageSharp

You should install one of these provides to make it actually working.

If none of the provider packages installed into your application, compress/resize operations return the untouched input image.

IImageResizer

You can inject the IImageResizer service and use it for image resize operations. Here is the available methods of the IImageResizer service:

public interface IImageResizer
{
    /* Works with a Stream object that represents an image */
    Task<ImageResizeResult<Stream>> ResizeAsync(
        Stream stream,
        ImageResizeArgs resizeArgs,
        string mimeType = null,
        CancellationToken cancellationToken = default
    );

    /* Works with a byte array that contains an image file */
    Task<ImageResizeResult<byte[]>> ResizeAsync(
        byte[] bytes,
        ImageResizeArgs resizeArgs,
        string mimeType = null,
        CancellationToken cancellationToken = default
    );
}

Example usage:

var resizeResult = await _imageResizer.ResizeAsync(
    imageStream, /* A stream object that represents an image */
    new ImageResizeArgs
    {
        Width = 100,
        Height = 100,
        Mode = ImageResizeMode.Crop
    },
    mimeType: "image/jpeg"
);

Note: If resizeResult.State returns 'Done', then it means that the resize operation was successful. However, if it returns any other state than 'Done', the stream you're using might be corrupted. Therefore, you can perform a check like the one below and assign the correct stream to the main stream:

if (resizeResult.Result is not null && imageStream != resizeResult.Result && resizeResult.Result.CanRead)
{
    await imageStream.DisposeAsync();
    imageStream = resizeResult.Result;
}

You can use MimeTypes.Image.Jpeg constant instead of the image/jpeg magic string used in that example.

ImageResizeArgs

The ImageResizeArgs is a class that is used to define the resize operation parameters. It has the following properties:

• Width: The width of the resized image.
• Height: The height of the resized image.
• Mode: The resize mode (see the ImageResizeMode section for more information).

ImageResizeMode

The ImageResizeMode is an enum that is used to define the resize mode. It has the following values:

public enum ImageResizeMode : byte
{
    None = 0,
    Stretch = 1,
    BoxPad = 2,
    Min = 3,
    Max = 4,
    Crop = 5,
    Pad = 6,
    Default = 7
}

See the ImageSharp documentation for more information about the resize modes.

ImageResizeResult

The ImageResizeResult is a generic class that is used to return the result of the image resize operations. It has the following properties:

• Result: The resized image (stream or byte array).
• State: The result of the resize operation (type: ImageProcessState).

ImageProcessState

The ImageProcessState is an enum that is used to return the the result of the image resize operations. It has the following values:

public enum ImageProcessState : byte
{
    Done = 1,
    Canceled = 2,
    Unsupported = 3,
}

ImageResizeOptions

ImageResizeOptions is an options object that is used to configure the image resize system. It has the following properties:

• DefaultResizeMode: The default resize mode. (Default: ImageResizeMode.None)

IImageCompressor

You can inject the IImageCompressor service and use it for image compression operations. Here is the available methods of the IImageCompressor service:

public interface IImageCompressor
{
    /* Works with a Stream object that represents an image */
    Task<ImageCompressResult<Stream>> CompressAsync(
        Stream stream,
        string mimeType = null,
        CancellationToken cancellationToken = default
    );
    
    /* Works with a byte array that contains an image file */
    Task<ImageCompressResult<byte[]>> CompressAsync(
        byte[] bytes,
        string mimeType = null,
        CancellationToken cancellationToken = default
    );
}

Example usage:

var compressResult = await _imageCompressor.CompressAsync(
    imageStream, /* A stream object that represents an image */
    mimeType: "image/jpeg"
);

Note: If compressResult.State returns 'Done', then it means that the compression operation was successful. However, if it returns any other state than 'Done', the stream you're using might be corrupted. Therefore, you can perform a check like the one below and assign the correct stream to the main stream:

if (compressResult.Result is not null && imageStream != compressResult.Result && compressResult.Result.CanRead)
{
    await imageStream.DisposeAsync();
    imageStream = compressResult.Result;
}

ImageCompressResult

The ImageCompressResult is a generic class that is used to return the result of the image compression operations. It has the following properties:

• Result: The compressed image (stream or byte array).
• State: The result of the compress operation (type: ImageProcessState).

ImageProcessState

The ImageProcessState is an enum that is used to return the the result of the image compress operations. It has the following values:

public enum ImageProcessState : byte
{
    Done = 1,
    Canceled = 2,
    Unsupported = 3,
}

Magick.NET Provider

Volo.Abp.Imaging.MagickNet NuGet package implements the image operations using the Magick.NET library.

Installation

You can add this package to your application by either using the ABP CLI or manually installing it. Using the ABP CLI is the recommended approach.

Using the ABP CLI

Open a command line terminal in the folder of your project (.csproj file) and type the following command:

abp add-package Volo.Abp.Imaging.MagickNet

Manual Installation

If you want to manually install;

1. Add the Volo.Abp.Imaging.MagickNet NuGet package to your project:

Install-Package Volo.Abp.Imaging.MagickNet

2. Add AbpImagingMagickNetModule to your module's dependency list:

[DependsOn(typeof(AbpImagingMagickNetModule))]
public class MyModule : AbpModule
{
    //...
}

Configuration

MagickNetCompressOptions is an options object that is used to configure the Magick.NET image compression system. It has the following properties:

• OptimalCompression: Indicates whether the optimal compression is enabled or not. (Default: false)
• IgnoreUnsupportedFormats: Indicates whether the unsupported formats are ignored or not. (Default: false)
• Lossless: Indicates whether the lossless compression is enabled or not. (Default: false)

ImageSharp Provider

Volo.Abp.Imaging.ImageSharp NuGet package implements the image operations using the ImageSharp library.

Installation

You can add this package to your application by either using the ABP CLI or manually installing it. Using the ABP CLI is the recommended approach.

Using the ABP CLI

Open a command line terminal in the folder of your project (.csproj file) and type the following command:

abp add-package Volo.Abp.Imaging.ImageSharp

Manual Installation

If you want to manually install;

1. Add the Volo.Abp.Imaging.ImageSharp NuGet package to your project:

Install-Package Volo.Abp.Imaging.ImageSharp

2. Add AbpImagingImageSharpModule to your module's dependency list:

[DependsOn(typeof(AbpImagingImageSharpModule))]
public class MyModule : AbpModule
{
    //...
}

Configuration

ImageSharpCompressOptions is an options object that is used to configure the ImageSharp image compression system. It has the following properties:

• DefaultQuality: The default quality of the JPEG and WebP encoders. (Default: 75)
• JpegEncoder: The JPEG encoder. (Default: JpegEncoder with Quality set to DefaultQuality)
• PngEncoder: The PNG encoder. (Default: PngEncoder with IgnoreMetadata set to true and CompressionLevel set to PngCompressionLevel.BestCompression)
• WebPEncoder: The WebP encoder. (Default: WebPEncoder with Quality set to DefaultQuality)

Example usage:

Configure<ImageSharpCompressOptions>(options =>
{
    options.JpegEncoder = new JpegEncoder
    {
        Quality = 60
    };
    options.PngEncoder = new PngEncoder
    {
        CompressionLevel = PngCompressionLevel.BestCompression
    };
    options.WebPEncoder = new WebPEncoder
    {
        Quality = 65
    };
});

ASP.NET Core Integration

Volo.Abp.Imaging.AspNetCore NuGet package defines attributes for controller actions that can automatically compress and/or resize uploaded files.

Installation

You can add this package to your application by either using the ABP CLI or manually installing it. Using the ABP CLI is the recommended approach.

Using the ABP CLI

Open a command line terminal in the folder of your project (.csproj file) and type the following command:

abp add-package Volo.Abp.Imaging.AspNetCore

Manual Installation

If you want to manually install;

1. Add the Volo.Abp.Imaging.AspNetCore NuGet package to your project:

Install-Package Volo.Abp.Imaging.AspNetCore

2. Add AbpImagingAspNetCoreModule to your module's dependency list:

[DependsOn(typeof(AbpImagingAspNetCoreModule))]
public class MyModule : AbpModule
{
    //...
}

CompressImageAttribute

The CompressImageAttribute is used to compress the image before. IFormFile, IRemoteStreamContent, Stream and IEnumrable<byte> types are supported. It has the following properties:

• Parameters: Names of the the parameters that are used to configure the image compression system. This is useful if your action has some non-image parameters. If you don't specify the parameters names, all of the method parameters are considered as image.

Example usage:

[HttpPost]
[CompressImage] /* Compresses the given file (automatically determines the file mime type) */
public async Task<IActionResult> Upload(IFormFile file)
{
    //...
}

ResizeImageAttribute

The ResizeImageAttribute is used to resize the image before requesting the action. IFormFile, IRemoteStreamContent, Stream and IEnumrable<byte> types are supported. It has the following properties:

• Parameters: Names of the the parameters that are used to configure the image resize system. This is useful if your action has some non-image parameters. If you don't specify the parameters names, all of the method parameters are considered as image.
• Width: Target width of the resized image.
• Height: Target height of the resized image.
• Mode: The resize mode (see the ImageResizeMode section for more information).

Example usage:

[HttpPost]
[ResizeImage(Width = 100, Height = 100, Mode = ImageResizeMode.Crop)] 
public async Task<IActionResult> Upload(IFormFile file)
{
    //...
}