ASP.NET Core 3.1 Images Compress

Yes, there are free and reliable ways to compress image files and create thumbnails in ASP.NET Core without using the System.Drawing.Common library, which is not supported in ASP.NET Core due to platform limitations. Here are two popular and widely used libraries that you can use:

ImageSharp (SixLabors.ImageSharp):
ImageSharp is a cross-platform, high-performance image processing library for .NET that can be used in ASP.NET Core applications. It provides a rich set of features for image manipulation, including resizing, cropping, compression, and more.
To use ImageSharp in your ASP.NET Core 3.1 MVC application, you need to install the SixLabors.ImageSharp.Web NuGet package.

Install-Package SixLabors.ImageSharp.Web

Here’s a sample code snippet to compress an image and generate a thumbnail using ImageSharp:

using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Processing;

public void ProcessImage(string inputFilePath, string outputFilePath, int maxWidth, int maxHeight)
{
    using (var image = Image.Load(inputFilePath))
    {
        // Resize the image to create a thumbnail
        image.Mutate(x => x.Resize(maxWidth, maxHeight));

        // Compress the image with the specified quality level (e.g., 70)
        var encoder = new SixLabors.ImageSharp.Formats.Jpeg.JpegEncoder { Quality = 70 };

        // Save the thumbnail to the output file
        image.Save(outputFilePath, encoder);
    }
}