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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta name="generator" content=
"HTML Tidy for Linux/x86 (vers 1st December 2004), see www.w3.org" />
<title>RMagick: class Image (instance methods, part 3)</title>
<meta http-equiv="Content-Type" content=
"text/html; charset=us-ascii" />
<meta name="GENERATOR" content="Quanta Plus" />
<meta name="Copyright" content=
"Copyright (C) 2006 by Timothy P. Hunter" />
<link rel="stylesheet" type="text/css" href="css/doc.css" />
<script type="text/javascript" src="scripts/doc.js">
</script>
<script type="text/javascript">
//<![CDATA[
<!-- Pre-load this image so that the browser knows how big it is. -->
<!-- Begin
flower_hat = new Image();
flower_hat.src = "ex/images/Flower_Hat.jpg";
// End -->
//]]>
</script>
<style type="text/css">
/*<![CDATA[*/
/*
* This style is used for the list of PreviewType
* constants defined for the preview method, below.
*/
#prevlist ul {
float: left;
list-style: none;
margin-bottom: 0;
}
/*
* This style is used for the list of QuantumOperator
* constants defined for the quantum_operator method, below.
*
*/
#quantum_op_list {
list-style-type: none;
}
/*]]>*/
</style>
</head>
<body>
<h6 id="header">RMagick User's Guide and Reference</h6>
<div class="nav">
« <a href="image2.html">Prev</a> | <a href=
"index.html">Contents</a> | <a href=
"draw.html">Next</a> »
</div>
<h1>class Image <span class="superclass">< Object</span>
(class and instance methods, part 3)<br />
<span class="mixin">mixes in Comparable</span></h1>
<div id="toc">
<h2>Table of Contents</h2>
<h3>instance methods</h3>
<div>
<div class="toccol">
<ul>
<li><a href="#preview">preview</a></li>
<li><a href="#profile_bang">profile!</a></li>
<li><a href="#properties">properties</a></li>
<li><a href="#quantize">quantize</a></li>
<li><a href="#quantum_operator">quantum_operator</a></li>
<li><a href="#radial_blur">radial_blur</a></li>
<li><a href="#raise">raise</a></li>
<li><a href=
"#random_threshold_channel">random_threshold_channel</a></li>
<li><a href="#reduce_noise">reduce_noise</a></li>
<li><a href="#resize">resize</a></li>
<li><a href="#resize_bang">resize!</a></li>
<li><a href="#roll">roll</a></li>
<li><a href="#rotate">rotate</a></li>
<li><a href="#rotate_bang">rotate!</a></li>
<li><a href="#sample">sample</a></li>
<li><a href="#sample_bang">sample!</a></li>
<li><a href="#scale">scale</a></li>
<li><a href="#scale_bang">scale!</a></li>
</ul>
</div>
<div class="toccol">
<ul>
<li><a href="#segment">segment</a></li>
<li><a href="#sepiatone">sepiatone</a></li>
<li><a href=
"#set_channel_depth">set_channel_depth</a></li>
<li><a href="#shade">shade</a></li>
<li><a href="#shadow">shadow</a></li>
<li><a href="#sharpen">sharpen</a></li>
<li><a href="#sharpen_channel">sharpen_channel</a></li>
<li><a href="#shave">shave</a></li>
<li><a href="#shave_bang">shave!</a></li>
<li><a href="#shear">shear</a></li>
<li><a href=
"#sigmoidal_contrast_channel">sigmoidal_contrast_channel</a></li>
<li><a href="#signature">signature</a></li>
<li><a href="#solarize">solarize</a></li>
<li><a href="#splice">splice</a></li>
<li><a href="#spread">spread</a></li>
<li><a href="#statistics">statistics</a></li>
<li><a href="#stegano">stegano</a></li>
<li><a href="#stereo">stereo</a></li>
</ul>
</div>
<div class="toccol">
<ul>
<li><a href="#store_pixels">store_pixels</a></li>
<li><a href="#strip_bang">strip!</a></li>
<li><a href="#swirl">swirl</a></li>
<li><a href=
"#texture_fill_to_border">texture_fill_to_border</a></li>
<li><a href=
"#texture_floodfill">texture_floodfill</a></li>
<li><a href="#threshold">threshold</a></li>
<li><a href="#thumbnail">thumbnail</a></li>
<li><a href="#thumbnail_bang">thumbnail!</a></li>
<li><a href="#to_blob">to_blob</a></li>
<li><a href="#to_color">to_color</a></li>
<li><a href="#transparent">transparent</a></li>
<li><a href="#trim">trim</a></li>
<li><a href="#trim_bang">trim!</a></li>
<li><a href="#unsharp_mask">unsharp_mask</a></li>
<li><a href=
"#unsharp_mask_channel">unsharp_mask_channel</a></li>
<li><a href="#view">view</a></li>
<li><a href="#wave">wave</a></li>
<li><a href="#white_threshold">white_threshold</a></li>
<li><a href="#write">write</a></li>
</ul>
</div>
</div>
</div>
<h2 class="methods">instance methods</h2>
<div class="sig">
<h3 id="preview">preview</h3>
<p><span class="arg">image</span>.preview(<span class=
"arg">aPreviewType</span>) -> <em>anImage</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p>Creates an image that contains 9 small versions of the
receiver image. The center image is the unchanged receiver. The
other 8 images are variations created by transforming the
receiver according to the specified preview type with varying
parameters.</p>
<p>A preview image is an easy way to "try out" a transformation
method.</p>
<h4>Arguments</h4>
<p>One of the following PreviewType constants:</p>
<div id="prevlist">
<ul>
<li>RotatePreview</li>
<li>ShearPreview</li>
<li>RollPreview</li>
<li>HuePreview</li>
<li>SaturationPreview</li>
<li>BrightnessPreview</li>
<li>GammaPreview</li>
<li>SpiffPreview</li>
<li>DullPreview</li>
<li>GrayscalePreview</li>
<li>QuantizePreview</li>
<li>DespecklePreview</li>
<li>ReduceNoisePreview</li>
<li>AddNoisePreview</li>
<li>SharpenPreview</li>
</ul>
<ul>
<li>BlurPreview</li>
<li>ThresholdPreview</li>
<li>EdgeDetectPreview</li>
<li>SpreadPreview</li>
<li>SolarizePreview</li>
<li>ShadePreview</li>
<li>RaisePreview</li>
<li>SegmentPreview</li>
<li>SwirlPreview</li>
<li>ImplodePreview</li>
<li>WavePreview</li>
<li>OilPaintPreview</li>
<li>CharcoalDrawingPreview</li>
<li>JPEGPreview</li>
</ul>
</div>
<div style="clear:both"></div>
<h4>Returns</h4>
<p>A new image</p>
<h4>Example</h4>
<p>This half-size preview demonstrates the SolarizePreview
argument.</p>
<p><a href="javascript:popup('preview.rb.html')"><img src=
"ex/preview.jpg" alt="preview example" title=
"Click to see the example script" /></a></p>
<h4>Magick API</h4>
<p>PreviewImage</p>
</div>
<div class="sig">
<h3 id="profile_bang">profile!</h3>
<p><span class="arg">image</span>.profile!(<span class=
"arg">name</span>, <span class="arg">profile</span>) ->
<em>image</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p><span class="imquote">Adds or removes a ICM, IPTC, or
generic profile from an image.</span> If <code>profile</code>
is <code>nil</code>, the specified profile is removed from the
image. Use <code>profile('*', nil)</code> to remove all
profiles from the image.</p>
<h4>Arguments</h4>
<dl>
<dt>name</dt>
<dd>The profile name, or "*" to represent all the profiles in
the image.</dd>
<dt>profile</dt>
<dd>The profile value, or <code>nil</code> to cause the
profile to be removed.</dd>
</dl>
<h4>Returns</h4>
<p>self</p>
<h4>Magick API</h4>
<p>ProfileImage</p>
<h4>Note</h4>
<p>×Magick does not automatically remove profiles when
resizing images. If you are trying to make your JPEG thumbnail
images as small as possible, use <code>profile!</code> to
remove any profiles from the image as well. Also see <a href=
"#strip_bang">strip!</a></p>
</div>
<div class="sig">
<h3 id="properties">properties</h3>
<p><span class="arg">image</span>.properties <span class=
"arg">[ {|name,value| block} ]</span> ->
<em>image</em><br />
<span class="arg">image</span>.properties ->
<em>aHash</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p>If called with an associated block, <code>properties</code>
runs the block once for each property defined for the image.
The block arguments are the property name and its value. If
there is no block, <code>properties</code> returns a hash with
one element for each property. The hash key is the property
name and the associated value is the property value.</p>
<h4>Returns</h4>
<p>If called without a block, returns a hash, otherwise returns
<code>self</code>.</p>
<h4>See also</h4>
<p><a href="image1.html#aref">[ ]</a>, <a href=
"image1.html#aset">[ ]=</a></p>
<h4>Note</h4>
<p>The EXIF property is not created until the first time an
EXIF tag or entry number is referenced.</p>
</div>
<div class="sig">
<h3 id="quantize">quantize</h3>
<p><span class="arg">image</span>.quantize(<span class=
"arg">number_colors</span>=256, <span class=
"arg">colorspace</span>=Magick::RGBColorspace, <span class=
"arg">dither</span>=<code>true</code>, <span class=
"arg">tree_depth</span>=0, <span class=
"arg">measure_error</span>=<code>false</code>) ->
<em>anImage</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p class="imquote">Analyzes the colors within a reference image
and chooses a fixed number of colors to represent the image.
The goal of the algorithm is to minimize the difference between
the input and output image while minimizing the processing
time.</p>
<h4>Arguments</h4>
<dl>
<dt>number_colors</dt>
<dd>The maximum number of colors in the result image. Must be
<= <a href=
"constants.html#Miscellaneous_constants">MaxRGB</a>.</dd>
<dt>colorspace</dt>
<dd class="imquote">The <a href=
"constants.html#ColorspaceType">colorspace</a> to quantize
in. Color reduction, by default, takes place in the RGB color
space. Empirical evidence suggests that distances
in color spaces such as YUV or YIQ correspond
to perceptual color differences more closely
than do distances in RGB space. The Transparent color
space behaves uniquely in that it preserves the matte channel
of the image if it exists.</dd>
<dt>dither</dt>
<dd class="imquote">Set to <code>true</code> to apply
Floyd/Steinberg error diffusion to the image. When the size
of the color palette is less than the image colors, this
trades off spacial resolution for color resolution by
dithering to achieve a similar looking image.</dd>
<dt>tree_depth</dt>
<dd class="imquote">The tree depth to use while quantizing.
The values 0 and 1 support automatic tree depth
determination. The tree depth may be forced via values
ranging from 2 to 8. The ideal tree depth depends on the
characteristics of the input image, and may be determined
through experimentation.</dd>
<dt>measure_error</dt>
<dd class="imquote">Set to <code>true</code> to calculate
quantization errors when quantizing the image.</dd>
</dl>
<h4>Returns</h4>
<p>A new image</p>
<h4>Example</h4>
<p>See the example for <a href=
"image1.html#colorize">colorize</a>.</p>
<h4>See also</h4>
<p><a href="image2.html#ordered_dither">ordered_dither</a>,
<a href="image2.html#posterize">posterize</a>, <a href=
"ilist.html#quantize">ImageList#quantize</a></p>
<h4>Magick API</h4>
<p>QuantizeImage</p>
</div>
<div class="sig">
<h3 id="quantum_operator">quantum_operator</h3>
<p><span class="arg">image</span>.quantum_operator(<span class=
"arg">operator</span>, <span class="arg">rvalue</span>,
<span class="arg">channel</span>=AllChannels) ->
<em>anImage</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p>Performs the requested integer arithmetic operation on the
selected channel of the image. This method allows simple
arithmetic operations on the component values of all pixels in
an image. Of course, you could also do this in Ruby using
<a href="image2.html#get_pixels">get_pixels</a> and <a href=
"#store_pixels">store_pixels</a>, or <a href="#view">view</a>,
but <code>quantum_operator</code> will be faster, especially
for large numbers of pixels, since it does not need to convert
the pixels from C to Ruby.</p>
<h4>Arguments</h4>
<dl>
<dt>operator</dt>
<dd>
One of the following <code>QuantumExpressionOperator</code>
constants:
<ul id="quantum_op_list">
<li>AddQuantumOperator</li>
<li><code>AndQuantumOperator</code></li>
<li><code>DivideQuantumOperator</code></li>
<li><code>LShiftQuantumOperator</code></li>
<li><code>MultiplyQuantumOperator</code></li>
<li><code>OrQuantumOperator</code></li>
<li><code>RShiftQuantumOperator</code></li>
<li><code>SubtractQuantumOperator</code></li>
<li><code>XorQuantumOperator</code></li>
</ul>
</dd>
<dt>rvalue</dt>
<dd>a <code>Numeric</code> operation rvalue.</dd>
<dt>channel</dt>
<dd>A <a href="constants.html#ChannelType">ChannelType</a>
constant. The default is to operate on all channels.</dd>
</dl>
<h4>Returns</h4>
<p>self</p>
<h4>Example</h4>
<p>Divide the red component of all the pixels in the image by
2:</p>
<pre>
img.quantum_operator(DivideQuantumOperator, 2, RedChannel)
</pre>
<h4>See also</h4>
<p>The <a href="struct.html#view">Image:View</a> class supports
operations on individual pixels and collections of pixels, as
well as operations on channels within pixels. See <a href=
"#view">view</a>, below.</p>
<h4>Magick API</h4>QuantumOperatorRegionImage (GraphicsMagick
1.1), EvaluateImageChannel (ImageMagick)
</div>
<div class="sig">
<h3 id="radial_blur">radial_blur</h3>
<p><span class="arg">image</span>.radial_blur(<span class=
"arg">aFloat</span>) -> <em>anImage</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p class="imquote">Applies a radial blur to the image.</p>
<h4>Arguments</h4>
<dl>
<dt>angle</dt>
<dd>Amount of blur, in degrees</dd>
</dl>
<h4>Returns</h4>
<p>A new image</p>
<h4>Example</h4>
<p class="rollover"><a href=
"javascript:popup('radial_blur.rb.html')"><img src=
"ex/radial_blur.jpg" onmouseover=
"this.src='ex/images/Flower_Hat.jpg'" onmouseout=
"this.src='ex/radial_blur.jpg'" alt="radial_blur example"
title="Click to see the example script" /></a> <img src=
"ex/images/spin.gif" alt="" class="spin" title=
"Mouse over the example to see the original image" /></p>
<h4>See also</h4>
<p><a href="image1.html#blur_image">blur_image</a>, <a href=
"image2.html#gaussian_blur">gaussian_blur</a>, <a href=
"image2.html#motion_blur">motion_blur</a></p>
<h4>Magick API</h4>
<p>RadialBlurImage</p>
</div>
<div class="sig">
<h3 id="raise">raise</h3>
<p><span class="arg">image</span>.raise(<span class=
"arg">width</span>=6, <span class="arg">height</span>=6,
<span class="arg">raised</span>=<code>true</code>) ->
<em>anImage</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p class="imquote">Creates a simulated three-dimensional
button-like effect by lightening and darkening the edges of the
image.</p>
<h4>Arguments</h4>
<dl>
<dt>width</dt>
<dd>The width of the raised edge in pixels. The default is
6.</dd>
<dt>height</dt>
<dd>The height of the raised edge in pixels. The default is
6.</dd>
<dt>raised</dt>
<dd>If <code>true</code>, the image is raised, otherwise
lowered.</dd>
</dl>
<h4>Returns</h4>
<p>A new image</p>
<h4>Example</h4>
<p class="rollover"><a href=
"javascript:popup('raise.rb.html')"><img src="ex/raise.jpg"
onmouseover="this.src='ex/images/Flower_Hat.jpg'" onmouseout=
"this.src='ex/raise.jpg'" alt="raise example" title=
"Click to see the example script" /></a> <img src=
"ex/images/spin.gif" alt="" class="spin" title=
"Mouse over the example to see the original image" /></p>
<h4>Magick API</h4>
<p>RaiseImage</p>
</div>
<div class="sig">
<h3 id="random_threshold_channel">random_threshold_channel</h3>
<p><span class="arg">image</span>.random_threshold_channel(
<span class="arg">thresholds</span>, [<span class=
"arg">channel</span>...] ) -> <em>anImage</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p class="imquote">Changes the value of individual pixels based
on the intensity of each pixel compared to a random threshold.
The result is a low-contrast, two color image.</p>
<h4>Arguments</h4>
<dl>
<dt>thresholds</dt>
<dd><span class="imquote">A geometry string containing
LOWxHIGH thresholds.</span> The string is in the form `XxY'.
The Y value may be omitted, in which case it is assigned the
value MaxRGB-X. If an % appears in the string then the values
are assumed to be percentages of MaxRGB. <span class=
"imquote">If the string contains 2x2, 3x3, or 4x4, then an
ordered dither of order 2, 3, or 4 will be performed
instead.</span> A <a href="struct.html#Geometry">Geometry</a>
object may be used as well.</dd>
<dt>channel...</dt>
<dd>0 or more <a href=
"constants.html#ChannelType">ChannelType</a> arguments. If no
channels are specified, all the channels are
thresholded.</dd>
</dl>
<h4>Returns</h4>
<p>A new image</p>
<h4>Example</h4>
<pre>
geom = Geometry.new(MaxRGB/2)
random_threshold_channel(geom, RedChannel)
</pre>
<p class="rollover"><a href=
"javascript:popup('random_threshold_channel.rb.html')"><img src="ex/random_threshold_channel.jpg"
alt="random_threshold_channel example" title=
"Click to see the example script" onmouseover=
"this.src='ex/images/Flower_Hat.jpg'" onmouseout=
"this.src='ex/random_threshold_channel.jpg'" /></a> <img src=
"ex/images/spin.gif" alt="" class="spin" title=
"Mouse over the example to see the original image" /></p>
<h4>See also</h4>
<p><a href=
"image1.html#adaptive_threshold">adaptive_threshold</a>,
<a href="image1.html#bilevel_channel">bilevel_channel</a>,
<a href="#threshold">threshold</a></p>
<h4>Magick API</h4>
<p>RandomThresholdImageChannel</p>
</div>
<div class="sig">
<h3 id="reduce_noise">reduce_noise</h3>
<p><span class="arg">image</span>.reduce_noise(<span class=
"arg">radius</span>) -> <em>anImage</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p class="imquote">Smooths the contours of an image while still
preserving edge information. The algorithm works by replacing
each pixel with its neighbor closest in value.</p>
<h4>Arguments</h4>
<dl>
<dt>radius</dt>
<dd class="imquote">A neighbor is defined by radius. Use a
radius of 0 and <code>reduce_noise</code> selects a suitable
radius for you.</dd>
</dl>
<h4>Returns</h4>
<p>A new image</p>
<h4>Example</h4>
<p>The left side of the image has been modified by <a href=
"#Image.add_noise"><code>add_noise</code></a>. The right side
has been filtered by <code>reduce_noise(0)</code>.</p>
<p><a href="javascript:popup('reduce_noise.rb.html')"><img src=
"ex/reduce_noise.jpg" title="Click to see the example script"
alt="reduce_noise example" /></a></p>
<h4>See also</h4>
<p><a href="image2.html#enhance">enhance</a>, <a href=
"#unsharp_mask">unsharp_mask</a></p>
<h4>Magick API</h4>
<p>ReduceNoiseImage</p>
</div>
<div class="sig">
<h3 id="resize">resize</h3>
<p><span class="arg">image</span>.resize(<span class=
"arg">new_width</span>, <span class="arg">new_height</span>,
<span class="arg">filter</span>=<a href=
"constants.html#FilterType">LanczosFilter</a>, <span class=
"arg">blur</span>=1.0) -> <em>anImage</em><br />
<span class="arg">image</span>.resize(<span class=
"arg">scale_factor</span>) -> <em>anImage</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p>Changes the size of the receiver to the specified
dimensions.</p>
<h4>Arguments</h4>
<p>You can specify the new size in two ways. Either specify the
new width and height explicitly, or specify a <em>scale
factor</em>, a number that represents the percentage
change.</p>
<p>Use the <a href=
"image1.html#change_geometry">change_geometry</a> method to
resize an image with constraints such as "maintain the current
proportions."</p>
<dl>
<dt>new_width, new_height</dt>
<dd>The desired width and height.</dd>
<dt>filter</dt>
<dd>The <a href="constants.html#FilterType">filter</a> to use
when resizing. If you do not specify a filter argument,
resize uses the value of the receiver's <a href=
"imageattrs.html#Image.filter">filter attribute</a>.
<span class="imquote">Most of the filters are FIR (finite
impulse response), however, Bessel, Gaussian, and Sinc are
IIR (infinite impulse response). Bessel and Sinc are windowed
(brought down to zero) with the Blackman filter.</span></dd>
<dt>blur</dt>
<dd>The blur factor. Values > 1 increase the blurriness.
Values < 1 increase the sharpness. If this argument is not
specified, <code>resize</code> uses the value of the
receiver's <a href="imageattrs.html#Image.blur">blur</a>
attribute.</dd>
<dt>scale_factor</dt>
<dd>You can use this argument instead of specifying the
desired width and height. The percentage size change. For
example, 1.25 makes the new image 125% of the size of the
receiver. The scale factor 0.5 makes the new image 50% of the
size of the receiver.</dd>
</dl>
<h4>Returns</h4>
<p>A new image</p>
<h4>See also</h4>
<p><a href="image1.html#change_geometry">change_geometry</a>
<a href="#resize_bang">resize!</a>, <a href=
"image2.html#magnify">magnify</a>, <a href=
"image2.html#minify">minify</a>, <a href="#sample">sample</a>,
<a href="#scale">scale</a>, <a href=
"thumbnail">thumbnail</a></p>
<h4>Magick API</h4>
<p>ResizeImage</p>
</div>
<div class="sig">
<h3 id="resize_bang">resize!</h3>
<p><em>image</em>.resize!(<em>new_width</em>,
<em>new_height</em>, <em>filter</em>=<a href=
"constants.html#FilterType">LanczosFilter</a>,
<em>blur</em>=1.0) -> <em>image</em><br />
<span class="arg">image</span>.resize!(<span class=
"arg">scale_factor</span>) -> <em>image</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p>In-place form of <a href="#Image.resize">resize</a>.</p>
<h4>Returns</h4>
<p>self</p>
</div>
<div class="sig">
<h3 id="roll">roll</h3>
<p><span class="arg">image</span>.roll(<span class=
"arg">x_offset</span>, <span class="arg">y_offset</span>) ->
<em>anImage</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p class="imquote">Offsets an image as defined by <span class=
"arg">x_offset</span> and <span class=
"arg">y_offset</span>.</p>
<h4>Arguments</h4>
<dl>
<dt>x_offset</dt>
<dd>The number of columns to offset the image.</dd>
<dt>y_offset</dt>
<dd>The number of rows to offset the image.</dd>
</dl>
<h4>Returns</h4>
<p>A new image</p>
<h4>Example</h4>
<p>This image has been offset 25% in both directions.</p>
<p class="rollover"><a href=
"javascript:popup('roll.rb.html')"><img src="ex/roll.jpg"
title="Click to see the example script" alt="roll example"
onmouseover="this.src='ex/images/Flower_Hat.jpg'" onmouseout=
"this.src='ex/roll.jpg'" /></a><img src="ex/images/spin.gif"
alt="" class="spin" title=
"Mouse over the example to see the original image" /></p>
<h4>Magick API</h4>
<p>RollImage</p>
</div>
<div class="sig">
<h3 id="rotate">rotate</h3>
<p><span class="arg">image</span>.rotate(<span class=
"arg">amount</span>) -> <em>anImage</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p>Rotate the receiver by the specified angle. <span class=
"imquote">Positive angles rotate counter-clockwise (right-hand
rule), while negative angles rotate clockwise. Rotated images
are usually larger than the originals and have "empty"
triangular corners. Empty triangles left over from shearing the
image are filled with the color defined by the pixel at
location (0,0).</span></p>
<h4>Arguments</h4>
<p>The number of degrees to rotate the image.</p>
<h4>Returns</h4>
<p>A new image</p>
<h4>Example</h4>
<p class="rollover"><a href=
"javascript:popup('rotate_f.rb.html')"><!--
This img tag displays the original image when the mouse is over.
Use CSS to add padding around the image to make it occupy the
same space as the rotated image. --><img style="padding-top:34px;padding-bottom:34px; display:none"
id="notrotated" onmouseout=
"this.style.display='none'; rotated.style.display='';" src=
"ex/images/Flower_Hat.jpg" alt="rotate example" title=
"Click to see the example script" /><!--
This img tag displays the rotated image.
--><img class="hide"
id="rotated" onmouseover=
"this.style.display='none'; notrotated.style.display='';" src=
"ex/rotate_f.jpg" alt="rotate example" /></a>
<img src="ex/images/spin.gif" alt="" class="spin" style=
"left:322px;" title=
"Mouse over the example to see the original image" /></p>
<h4>See also</h4>
<p><a href="image1.html#affine_transform">affine_transform</a>,
<a href="#shear">shear</a></p>
<h4>Magick API</h4>
<p>RotateImage</p>
</div>
<div class="sig">
<h3 id="rotate_bang">rotate!</h3>
<p><span class="arg">image</span>.rotate!(<span class=
"arg">amount</span>) -> <em>image</em></p>
</div>
<div class="desc">
<h4>Description</h4>
<p>In-place form of <a href="#rotate">rotate</a>.</p>
<h4>Returns</h4>