How to reduce JPEG file size after compressing images using C# System.Drawing in .NET 6?

Hello @Shakeel khan ,

Thanks for your question.

System.Drawing JPEG encoder at Quality 50% is not efficient enough, it doesn't compress as well as modern image libraries, even at the same quality setting.

I recommend using ImageSharp since it produces significantly smaller files at the exact same quality level.

You can refer to following steps:

1. Installation

Install-Package SixLabors.ImageSharp

2. Code example

using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Formats.Jpeg;

public class ImageCompressor
{
    public static async Task<byte[]> CompressJpegAsync(Stream inputStream, int quality = 50)
    {
        using var image = await Image.LoadAsync(inputStream);

        image.Metadata.ExifProfile = null;
        image.Metadata.IptcProfile = null;
        image.Metadata.XmpProfile = null;

        var encoder = new JpegEncoder
        {
            Quality = quality,
            ColorType = JpegColorType.YCbCrRatio420
        };

        using var outputStream = new MemoryStream();
        await image.SaveAsJpegAsync(outputStream, encoder);

        return outputStream.ToArray();
    }

    public async Task<List<byte[]>> BatchCompressAsync(List<Stream> imageStreams, int quality = 50)
    {
        var results = new List<byte[]>();

        foreach (var chunk in imageStreams.Chunk(5))
        {
            var tasks = chunk.Select(stream => CompressJpegAsync(stream, quality));
            var compressed = await Task.WhenAll(tasks);
            results.AddRange(compressed);
        }

        return results;
    }
}

For more information on how to use, you can refer to this main document.

While this is a non-Microsoft link, it’s official SIX LABORS documentation and is safe to visit.

I hope this addresses your question. If this response was helpful, please consider following the guidance to provide feedback.