using copy() to copy part of canvas to another graphic

Geoffree3

I want to copy parts of the canvas to another image, which is then output as a single file. However, it appears that copy() doesn't take any notice of the pixel density as I get a low res. output. If I save the canvas directly to a file using save() I get high res. from my MacBook retina screen. Any ideas?

What I do:
use output = createImage() to define the image which is eventually output use output.copy(,

,, "png")

Geoffree3

hasn't written 'what I do' correctly .. should be:

use output = createImage() to define the image which is eventually output

use output.copy({p5 canvas}, {region of canvas as x,y,w,h}, {region of output to copy to as x,y,w,h})

.. then when done copying all regions ...

save(output, {filename}, 'png')