This Action is for use with Photoshop’s Image Processing script. It batch sizes images down to 2500 px without upsampling images that are smaller than 2500 px. Download and unpack the zip file here: Image Processing-unpack
1) Open Photoshop
2) Go to the Actions palette > Load Actions. Load “Image Processing.atn”.
3) Go to File > Scripts > Image Processor. Make selections for (1), (2), and (3). Be sure “Resize to Fit” is NOT checked in (3).
4) Under (4) Preferences, check “Run Action” and choose the Action you loaded in step 2 from the drop-down menus.
4) Click Run.