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ImageMagick Identify Command-line Tool

The identify program describes the format and characteristics of one or more image files. It also reports if an image is incomplete or corrupt. The information returned includes the image number, the file name, the width and height of the image, whether the image is colormapped or not, the number of colors in the image, the number of bytes in the image, the format of the image (JPEG, PNM, etc.), and finally the number of seconds it took to read and process the image. Many more attributes are available with the verbose option. See Command Line Processing for advice on how to structure your identify command or see below for example usages of the command.

Example Usage

We list a few examples of the identify command here to illustrate its usefulness and ease of use. To get started, lets identify an image in the JPEG format:

$ identify rose.jpg rose.jpg JPEG 640x480 sRGB 87kb 0.050u 0:01

Next, we look at the same image in greater detail:

$ identify -verbose rose.jpgImage: rose.jpg

Format: JPEG (Joint Photographic Experts Group JFIF format)

Class: DirectClass

Geometry: 70x46+0+0

Resolution: 72x72

Print size: 0.972222x0.638889

Units: PixelsPerInch

Type: TrueColor

Endianess: Undefined

Colorspace: RGB

Depth: 8-bit

Channel depth:

red: 8-bit

green: 8-bit

blue: 8-bit

Channel statistics:

red:

min: 37 (0.145098)

max: 255 (1)

mean: 145.58 (0.5709)

standard deviation: 67.3195 (0.263998)

green:

min: 31 (0.121569)

max: 255 (1)

mean: 89.2512 (0.350005)

standard deviation: 52.0488 (0.204113)

blue:

min: 17 (0.0666667)

max: 255 (1)

mean: 80.4075 (0.315323)

standard deviation: 54.0052 (0.211785)

Rendering intent: Undefined

Interlace: None

Background color: white

Border color: rgb(223,223,223)

Matte color: grey74

Transparent color: black

Page geometry: 70x46+0+0

Dispose: Undefined

Iterations: 0

Compression: JPEG

Quality: 100

Orientation: Undefined

Properties:

date:create: 2008-01-08T11:08:52-05:00

date:modify: 2005-04-07T12:48:13-04:00

jpeg:colorspace: 2

jpeg:sampling-factor: 2x2,1x1,1x1

signature: dcd00d6303f80f4fa53f991804cb026151c1e851b7a96255e82da87299583ebc

Artifacts:

verbose: true

Tainted: False

Filesize: 3.97266kb

Number pixels: 3.14453kb

Version: ImageMagick 6.8.6-8 2013-07-15 Q16 http://www.imagemagick.org

To get the print size in inches of an image at 72 DPI, use:

$ identify -format "%[fx:w/72] by %[fx:h/72] inches" document.png8.5 x 11 inches

The depth and dimensions of a raw image must be specified on the command line:

$ identify -depth 8 -size 640x480 image.rawimage.raw RGB 640x480 sRGB 9kb 0.000u 0:01

Here we display the image texture features and the number of unique colors in the image:

$ identify -verbose -features 1 -unique image.png

You can find additional examples of using identify in Examples of ImageMagick Usage.

Option Summary

The identify command recognizes these options. Click on an option to get more details about how that option works.

Option Description
-alpha on, activate, off, deactivate, set, opaque, copy", transparent, extract, background, or shape the alpha channel
-antialias remove pixel-aliasing
-authenticate value decrypt image with this password
-channel type apply option to select image channels
-clip clip along the first path from the 8BIM profile
-clip-mask filename associate clip mask with the image
-clip-path id clip along a named path from the 8BIM profile
-colorspace type set image colorspace
-crop geometry crop the image
-debug events display copious debugging information
-define format:option define one or more image format options
-density geometry horizontal and vertical density of the image
-depth value image depth
-endian type endianness (MSB or LSB) of the image
-extract geometry extract area from image
-features distance analyze image features (e.g. contract, correlations, etc.).
-format string output formatted image characteristics
-gamma value level of gamma correction
-help print program options
-interlace type type of image interlacing scheme
-interpolate method pixel color interpolation method
-limit type value pixel cache resource limit
-list type Color, Configure, Delegate, Format, Magic, Module, Resource, or Type
-log format format of debugging information
-mask filename associate a mask with the image
-monitor monitor progress
-negate replace each pixel with its complementary color
-quiet suppress all warning messages
-regard-warnings pay attention to warning messages.
-respect-parentheses settings remain in effect until parenthesis boundary.
-sampling-factor geometry horizontal and vertical sampling factor
-set attribute value set an image attribute
-size geometry width and height of image
-strip strip image of all profiles and comments
-unique display image the number of unique colors in the image.
-units type the units of image resolution
-verbose print detailed information about the image
-version print version information
-virtual-pixel method access method for pixels outside the boundaries of the image