ImageSharp 3.0 global configuration for decoders

[hey-red]

In 2.x version we could set a global configuration for decoders:

configuration.ImageFormatsManager.SetDecoder(GifFormat.Instance, new GifDecoder()
{
       DecodingMode = FrameDecodingMode.First,
});

How to achieve this in 3.0? Or the only way is to use a decoder instance?

var image = JpegDecoder.Instance.Decode(new JpegDecoderOptions { ResizeMode = JpegDecoderResizeMode.ScaleOnly }, input);

[tocsoft]

What are you seeing that implies your first code snippet doesn't work?

[JimBobSquarePants]

You can pass that configuration via the DecoderOptions. It has a Configuration property that defaults to the default shared instance.

[hey-red]

@JimBobSquarePants Yes, I see, but I don't understand how do this with JpegDecoderOptions.ResizeMode

All options that implements ISpecializedDecoderOptions can be used only with decoder instance, and not possible to set it on global configuration, right?

[JimBobSquarePants]

Yes. The general options are for general use cases. I.E. Image.Load etc.

Using the decoders directly is an advanced process not recommended for general use.

You should only use the decoder directly if you require specialist options and only if you are 100% confident that you know the type of image you are decoding. (I’ve soon far too many people complain because they’ve tried to decode file with the wrong extension directly with a decoder)

You can use the Image.DetectFormat APIs to identify unknown types before choosing the correct decoder if you do not know it.

You’ve not lost functionality. You’ve gained new functionality.

The API redesign is specifically implemented to provide guidance as to the correct path to choose to avoid common foot guns.

[hey-red]

@JimBobSquarePants Understood. Looks reasonable.
The one problem that I can see that ImageSharp.Web(v2) does't provide an alternative api for this use case.
Thanks for help.

[JimBobSquarePants]

Yet… Still working on the next release of that library.