Get image width and height with ImageMagick

You can ask ImageMagick for details of image files with the identify. Say, their dimensions (width and height), their resolution (pixels-per-inch), or many other details.

You can run the identify by itself to get a series of default details.

The Identify command

identify image.jpg
# image.jpg JPEG 1600x1659 1600x1659+0+0 8-bit sRGB 475062B 0.010u 0:00.002

The -verbose flag

Or even to obtain greater details with the -verbose flag. (Note that this command returns more than 300 lines of information per image, so I'm omitting most of what was returned.)

identify -verbose image.jpg
# Image:
#  Filename: image.jpg
#  Format: JPEG (Joint Photographic Experts Group JFIF format)
#  Mime type: image/jpeg
#  Class: DirectClass
#  Geometry: 1600x1659+0+0
#  Resolution: 200x200
#  ...

Width and Height of a single image

identify -format "%wx%h" image.jpg
# 1600x1659

Width and Height of multiple images in a directory

identify -format "%wx%h\n" *.jpg
# 1983x1969
# 1912x1803
# 2173x2126
# 1807x1669
# ...

Dimensions and names

identify -format "%wx%h - %f\n" *.jpg
# 1983x1969 - image-01.jpg
# 1912x1803 - image-02.jpg
# 2173x2126 - image-03.jpg
# 1807x1669 - image-04.jpg
# ...

For reference, here are ImageMagick's identify docs.