identify <image>
To resize a large image to be at most 500px wide (and proportional height)
convert input.jpg -resize 500 output.jpg
You can even resize the image in place and overwrite it convert image.jpg -resize 500 image.jpg
convert -append <first.jpg> <second.jpg> ... <output.jpg>
Use -append
for vertical strip. Use +append
for horizontal strip.