macOS command to resize a hi-res image in the pasteboard to a normal size image, for pasting into applications that don't handle HPDI

pbresize

#!/bin/bash

# Usage:
# copy image to pasteboard via CMD-C
# then call pbresize on command line
# or call with a custom scale e.g. pbresize 0.7

SCALE_FACTOR=${1:-0.5}

pngpaste /tmp/ss.png
IMG_WIDTH=$(sips -g pixelWidth /tmp/ss.png | cut -s -d ':' -f 2 | cut -c 2-) 
SCALED_WIDTH=$(echo "$IMG_WIDTH * $SCALE_FACTOR" | bc)
sips -Z $SCALED_WIDTH /tmp/ss.png
impbcopy /tmp/ss.png