Image & Canvas

[MahaB82A]

It is a PNG folder icon in the windows explorer. This icon was opened in the Ps work area. Is it correct to say folder is an image and regioned marked with a red line is a canvas? Because triming the canvas is changing the image size of the image.

[D Fosse]

What do you mean by trimming the image? Is that Image > Trim? That's what it's supposed to do.

Incidentally, Export will also do this. The sole purpose of Export is to cut the file size as much as possible, so transparent pixels outside the layer content will be removed.

[MahaB82A]

Yes, Image > Trim

Just test this command & came with this issue. 

My understanding is you only trim the canvas therefore image size should remain intact.  

[D Fosse]

It's behaving as designed. This is what Image > Trim does.