Legacy ImageMagick Discussions Archive

Hi,

I'm just curious on how convert will work if I convert an image to a different location with the same extension. Will the algorithm knows that no conversion is needed, and thus just copy the file to the other location?

For example,
"convert af1.pgm ./temp/af1.pgm"

A simple test tells me that it will create the af1.pgm in temp directory, but I'm just wondering if the algorithm just do a file copy or actually "converts" it (which takes more time, more calculations, and same result)?

Thanks,
onyee

If you convert an image onto itself, the convert program will read the image file and then write it back out to the same image file location.

Of course some image formats will thus change. JPEG will have some image compression degrading, PNG might be saved in a different style (basied on content), and some formats include date information.

I suggest you actually copy when you mean copy.