I have create a go sdk, but upload image file occurred an error

Question

I try to develop a sdk of golang for oxford-project,bug have occurred a problem.

When I try to upload image to the api server, it responses an error code : "Decoding error, image format unsupported."

The code is here:https://github.com/opensdk/go-ms-oxford and in the examples/detection folder.

Any body can help me ?

Thank you.