image: decode a png file return unknown format

[hmvhamide]

What version of Go are you using (go version)?

$ go version
go version go1.17 linux/amd64

Does this issue reproduce with the latest release?

What operating system and processor architecture are you using (go env)?

go env Output

$ go env

What did you do?

I open a png image file and decode it in the following code, it returns unknown format.
The image

is attached.
Code: https://go.dev/play/p/op3ILPNJmCw

What did you expect to see?

I expect the code to finish without error. Because this is a valid png file and can be opened with image editors like GIMP.

What did you see instead?

The following error printed:
error decoding image image: unknown format

[mdlayher]

Please see the package docs and example. https://pkg.go.dev/image