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<h1 class="text-center">Image Format and Characteristics</h1>
<p class="text-center"><a href="identify.html#usage">Example Usage</a><a href="identify.html#options">Option Summary</a></p>
<p class="lead magick-description">The <code>identify</code> 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 <a href="command-line-processing.html">Command Line Processing</a> for advice on how to structure your <code>identify</code> command or see below for example usages of the command.</p>
<h2><a class="anchor" id="usage"></a>Example Usage</h2>
<p>We list a few examples of the <code>identify</code> command here to illustrate its usefulness and ease of use. To get started, lets identify an image in the JPEG format:</p>
<pre class="highlight"><code>-> identify rose.jpg
rose.jpg JPEG 70x46 70x46+0+0 8-bit sRGB 2.36KB 0.000u 0:00.000
</code></pre>
<p>By default, <code>identify</code> provides the following output:</p>
<p><code>Filename[frame #] image-format widthxheight page-widthxpage-height+x-offset+y-offset colorspace user-time elapsed-time</code></p>
<p>Next, we look at the same image in greater detail:</p>
<pre class="pre-scrollable"><code>-> identify -verbose rose.jpg
Image: rose.jpg
Format: JPEG (Joint Photographic Experts Group JFIF format)
Mime type: images/jpeg
Class: DirectClass
Geometry: 70x46+0+0
Units: Undefined
Type: TrueColor
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Pixels: 3220
Red:
min: 35 (0.137255)
max: 255 (1)
mean: 145.57 (0.570865)
standard deviation: 67.2976 (0.263912)
kurtosis: -1.37971
skewness: 0.0942169
entropy: 0.974889
Green:
min: 33 (0.129412)
max: 255 (1)
mean: 89.2193 (0.349879)
standard deviation: 52.0803 (0.204236)
kurtosis: 2.70722
skewness: 1.82562
entropy: 0.877139
Blue:
min: 11 (0.0431373)
max: 255 (1)
mean: 80.3742 (0.315193)
standard deviation: 53.8536 (0.21119)
kurtosis: 2.90978
skewness: 1.92617
entropy: 0.866692
Image statistics:
Overall:
min: 11 (0.0431373)
max: 255 (1)
mean: 105.055 (0.411979)
standard deviation: 58.1422 (0.228008)
kurtosis: 1.25759
skewness: 1.4277
entropy: 0.90624
Rendering intent: Perceptual
Gamma: 0.454545
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Background color: white
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Interlace: None
Intensity: Undefined
Compose: Over
Page geometry: 70x46+0+0
Dispose: Undefined
Iterations: 0
Compression: JPEG
Quality: 92
Orientation: Undefined
Properties:
date:create: 2014-11-09T09:00:35-05:00
date:modify: 2014-11-09T09:00:35-05:00
jpeg:colorspace: 2
jpeg:sampling-factor: 2x2,1x1,1x1
signature: 22a99838bd5594250f706d1d9383b2830f439fcbaf1455cbe2f7f59a4deb065a
Artifacts:
filename: rose.jpg
verbose: true
Tainted: False
Filesize: 2.36KB
Number pixels: 3.22K
Pixels per second: 3.22EB
User time: 0.000u
Elapsed time: 0:01.000
Version: ImageMagick Q16 https://imagemagick.org
</code></pre>
<p>To get the print size in inches of an image at 72 DPI, use:</p>
<pre class="highlight"><code>-> identify -format "%[fx:w/72] by %[fx:h/72] inches" document.png
8.5 x 11 inches
</code></pre>
<p>The depth and dimensions of a raw image must be specified on the command line:</p>
<pre class="highlight"><code>-> identify -depth 8 -size 640x480 image.raw
image.raw RGB 640x480 sRGB 9kb 0.000u 0:01
</code></pre>
<p>Here we display the image texture features, moments, perceptual hash, and the number of unique colors in the image:</p>
<pre class="highlight"><code>-> identify -verbose -features 1 -moments -unique image.png
</code></pre>
<p>Here is a special define that outputs the location of the minimum or maximum pixel of the image:</p>
<pre class="highlight"><code>identify -precision 5 -define identify:locate=maximum -define identify:limit=3 image.png
</code></pre>
<p>You can find additional examples of using <code>identify</code> in <a href="https://legacy.imagemagick.org/Usage/">Examples of ImageMagick Usage</a>.</p>
<h2><a class="anchor" id="options"></a>Option Summary</h2>
<p>The <code>identify</code> command recognizes these options. Click on an option to get more details about how that option works.</p>
<table class="table table-sm table-hover">
<tbody>
<tr>
<th align="left">Option</th>
<th align="left">Description</th>
</tr>
<tr>
<td><a href="command-line-options.html#alpha">-alpha</a></td>
<td>on, activate, off, deactivate, set, opaque, copy",
transparent, extract, background, or shape the alpha channel</td>
</tr>
<tr>
<td><a href="command-line-options.html#antialias">-antialias</a></td>
<td>remove pixel-aliasing</td>
</tr>
<tr>
<td><a href="command-line-options.html#authenticate">-authenticate <var>value</var></a></td>
<td>decrypt image with this password</td>
</tr>
<tr>
<td><a href="command-line-options.html#channel">-channel <var>type</var></a></td>
<td>apply option to select image channels</td>
</tr>
<tr>
<td><a href="command-line-options.html#clip">-clip</a></td>
<td>clip along the first path from the 8BIM profile</td>
</tr>
<tr>
<td><a href="command-line-options.html#clip-mask">-clip-mask</a> <var>filename</var></td>
<td>associate clip mask with the image</td>
</tr>
<tr>
<td><a href="command-line-options.html#clip-path">-clip-path <var>id</var></a></td>
<td>clip along a named path from the 8BIM profile</td>
</tr>
<tr>
<td><a href="command-line-options.html#colorspace">-colorspace <var>type</var></a></td>
<td>set image colorspace</td>
</tr>
<tr>
<td><a href="command-line-options.html#crop">-crop <var>geometry</var></a></td>
<td>crop the image</td>
</tr>
<tr>
<td><a href="command-line-options.html#debug">-debug <var>events</var></a></td>
<td>display copious debugging information</td>
</tr>
<tr>
<td><a href="command-line-options.html#define">-define <var>format:option</var></a></td>
<td>define one or more image format options</td>
</tr>
<tr>
<td><a href="command-line-options.html#density">-density <var>geometry</var></a></td>
<td>horizontal and vertical density of the image</td>
</tr>
<tr>
<td><a href="command-line-options.html#depth">-depth <var>value</var></a></td>
<td>image depth</td>
</tr>
<tr>
<td><a href="command-line-options.html#endian">-endian <var>type</var></a></td>
<td>endianness (MSB or LSB) of the image</td>
</tr>
<tr>
<td><a href="command-line-options.html#extract">-extract <var>geometry</var></a></td>
<td>extract area from image</td>
</tr>
<tr>
<td><a href="command-line-options.html#features">-features <var>distance</var></a></td>
<td>analyze image features (e.g. contract, correlations, etc.).</td>
</tr>
<tr>
<td><a href="command-line-options.html#format_identify_">-format <var>string</var></a></td>
<td>output formatted image characteristics</td>
</tr>
<tr>
<td><a href="command-line-options.html#gamma">-gamma <var>value</var></a></td>
<td>level of gamma correction</td>
</tr>
<tr>
<td><a href="command-line-options.html#grayscale">-grayscale <var>method</var></a></td>
<td>convert image to grayscale</td>
</tr>
<tr>
<td><a href="command-line-options.html#help">-help</a></td>
<td>print program options</td>
</tr>
<tr>
<td><a href="command-line-options.html#interlace">-interlace <var>type</var></a></td>
<td>type of image interlacing scheme</td>
</tr>
<tr>
<td><a href="command-line-options.html#interpolate">-interpolate <var>method</var></a></td>
<td>pixel color interpolation method</td>
</tr>
<tr>
<td><a href="command-line-options.html#limit">-limit <var>type value</var></a></td>
<td>pixel cache resource limit</td>
</tr>
<tr>
<td><a href="command-line-options.html#list">-list <var>type</var></a></td>
<td>Color, Configure, Delegate, Format, Magic, Module, Resource, or Type</td>
</tr>
<tr>
<td><a href="command-line-options.html#log">-log <var>format</var></a></td>
<td>format of debugging information</td>
</tr>
<tr>
<td><a href="command-line-options.html#mask">-mask <var>filename</var></a></td>
<td>associate a mask with the image</td>
</tr>
<tr>
<td><a href="command-line-options.html#moments">-moments</a></td>
<td>display image moments and perceptual hash.</td>
</tr>
<tr>
<td><a href="command-line-options.html#monitor">-monitor</a></td>
<td>monitor progress</td>
</tr>
<tr>
<td><a href="command-line-options.html#negate">-negate</a></td>
<td>replace each pixel with its complementary color </td>
</tr>
<tr>
<td><a href="command-line-options.html#ping">-ping</a></td>
<td>by default, efficiently determine certain image characteristics.</td>
</tr>
<tr>
<td><a href="command-line-options.html#precision">-precision <var>value</var></a></td>
<td>set the maximum number of significant digits to be printed</td>
</tr>
<tr>
<td><a href="command-line-options.html#quiet">-quiet</a></td>
<td>suppress all warning messages</td>
</tr>
<tr>
<td><a href="command-line-options.html#regard-warnings">-regard-warnings</a></td>
<td>pay attention to warning messages.</td>
</tr>
<tr>
<td><a href="command-line-options.html#respect-parentheses">-respect-parentheses</a></td>
<td>settings remain in effect until parenthesis boundary.</td>
</tr>
<tr>
<td><a href="command-line-options.html#sampling-factor">-sampling-factor <var>geometry</var></a></td>
<td>horizontal and vertical sampling factor</td>
</tr>
<tr>
<td><a href="command-line-options.html#set">-set <var>attribute value</var></a></td>
<td>set an image attribute</td>
</tr>
<tr>
<td><a href="command-line-options.html#size">-size <var>geometry</var></a></td>
<td>width and height of image</td>
</tr>
<tr>
<td><a href="command-line-options.html#strip">-strip</a></td>
<td>strip image of all profiles and comments</td>
</tr>
<tr>
<td><a href="command-line-options.html#unique">-unique</a></td>
<td>display image the number of unique colors in the image.</td>
</tr>
<tr>
<td><a href="command-line-options.html#units">-units <var>type</var></a></td>
<td>the units of image resolution</td>
</tr>
<tr>
<td><a href="command-line-options.html#verbose">-verbose</a></td>
<td>print detailed information about the image</td>
</tr>
<tr>
<td><a href="command-line-options.html#version">-version</a></td>
<td>print version information</td>
</tr>
<tr>
<td><a href="command-line-options.html#virtual-pixel">-virtual-pixel <var>method</var></a></td>
<td>access method for pixels outside the boundaries of the image</td>
</tr>
</tbody>
</table>
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