WebP at Quality = 50 results in 5 times larger file size than JPG

[JwanKhalaf]

Let me begin by saying thank you to all those that are working on this amazing library during their free time. 🙏

I wanted to get your thoughts on something. I am working in a .NET 6 MVC application. I have a form where the user can upload an image file (.jpg or .png only).

I am using IFormFile in my ViewModel, I then turn that into an Image from ImageSharp so that I can re-size the image, and convert it to .webp.

I am using SixLabors.ImageSharp -Version 2.0.0-alpha.0.159 from MyGet. My code "works", but I am surprised by the result. .webp is supposed to be a file that is smaller in size than .jpg, yet I get:

Notice how the .webp file is about 5 times larger than the .jpg file. I suspect I am doing something silly, I just don't know what.

My whole project is open-source and I have a branch created for the current work. Here is where I grab the file and turn it into an ImageSharp Image. Here is where I set the quality of the image to 50.

Can anyone see what I'm doing wrong?

[brianpopow]

@JwanKhalaf can you attach an example image here, so we can reproduce this?

[brianpopow]

Ok this explains it. If you do not set the WebP file format when encoding the image, it will default to lossless (we need to make sure to mention this, once we release the a update to the doc's).

If you set it to Lossy, the image will be smaller:

image.Save("output.webp", new WebpEncoder()
{
   FileFormat = WebpFileFormatType.Lossy
});

The output image is 6KB. But keep in mind, that this not guaranteed to be always the case. There can be images which compress better with jpg nonetheless.

[JimBobSquarePants]

Is Lossy or Lossless the default with libwebp? This default will cause a LOT of surprises with ImageSharp.Web.

[brianpopow]

I have just checked libwebp: Lossy is the default there. I think we should should change ours to match that.

edit: changed with #1961

[JimBobSquarePants]

Yep definitely. 👍

[JwanKhalaf]

Thank you so much @brianpopow! You were right! After making the change, it now works as expected.

[br3aker]

.webp is supposed to be a file that is smaller in size than .jpg

It really depends on the input image.