[FIXED] How to batch-resize PNG files?

Issue

I have a number of PNG image files that I'd like to increase in size. I do not want to rescale the image. I just want to extend the white background further down and to the right. In GIMP terms what I want is to increase the Canvas Size, and cover the increased area with white pixels, in a batch context. The input images may be different sizes, but the output images should all be a fixed size (e.g.: 1280 x 720 pixels).

I've tried this with various online tools, with GIMP, and with a very old version of Photoshop. Most of the tools I've tried to date do one of the following which I don't want:

• Rescale the existing image to cover the new canvas size, or
• Center the starting image and extend the canvas in all directions, or
• Fail to perform this in a batch mode.

I just want to extend existing PNG images with additional white pixels down and to the right. What's the easiest way to do this to a large number of files?

Solution

The ImageMagick command that did what I needed used "convert" with the -geometry and -composite arguments. In a Windows batch file context:

for %%a in (img*.png) do (
   magick convert -size 1280x720 xc:white "%%a" -geometry 512x384+40+40 -composite "work-%%~na.pdf"
)

Answered By - Daniel R. Collins

Answer Checked By - Clifford M. (PHPFixing Volunteer)