module Magick

Description

Lists the named colors. If the optional block is present, calls the block once for each color, passing a Magick::Color object. Otherwise, returns an array of Magick::Color objects, one for each color.

The Magick::Color class is a Struct class with the following attributes:

Magick::Color attributes

Attribute	Value
name	The color name. For example, "red".
compliance	A ComplianceType value such as X11Compliance.
color	A Pixel object containing the RGB values.

Returns

If no block is associated with the call, returns an array of Magick::Color objects.

Example

This is a small sample of colors.miff, the complete image created by the example program.

Magick API

GetColorInfo

Description

Lists the fonts that ×Magick knows about. If the optional block is present, calls the block once for each font, passing a Magick::Font object. Otherwise, returns an array of Magick::Font objects, one for each font.

The Magick::Font class is a Struct class with the following attributes:

Magick::Font attributes

Attribute	Value
name	The font name. For example, "Palatino-Roman".
description	The font description. For example, "Palatino Roman".
family	The font family. For example, "Palatino", "Helvetica", or "Courier".
style	A StyleType value such as NormalStyle.
stretch	A StretchType value such as NormalStretch.
weight	The font weight, one of 100, 200, 300, 400, 500, 600, 700, 800, or 900.
encoding	The font encoding, such as "AppleRoman". May be nil.
foundry	The font foundry. "URW", for example. May be nil.
format	If the font is a Type1 font, has the value "type1", otherwise nil.

Returns

If no block is associated with the call, returns an array of Magick::Font objects.

Example

fonts.rb

Magick API

GetFontInfo

Description

Describes the image formats supported by ×Magick. If the optional block is present, calls the block once for each image format. The first argument, f, is the format name. The second argument, v, is the properties string described below.

Returns

A hash of image formats and their properties. Each key in the returned hash is the name of a supported image format. Each value is a string in the form "BRWA". The details are in this table:

Format property codes

Code	Definition
B	is "*" if the format has native blob support, and "-" otherwise.
R	is "r" if ×Magick can read the format, and "-" otherwise.
W	is "w" if ×Magick can write the format, and "-" otherwise.
A	is "+" if the format supports multi-image files, and "-" otherwise.

Example

p Magick.formats »
   {"TIF"=>"*rw+",
   "H"=>"*rw-",
   "MNG"=>"*rw+",
   "NULL"=>"*rw-",
   ...
   "G"=>"*rw+",
   "GIF"=>"*rw+",
   "PDB"=>"*rw+"}

Magick API

GetMagickInfo

Note

×Magick depends on external programs for some formats. Depending on how ×Magick was installed on your system, some formats may not be available. If you have questions, ask your system administrator.

Description

Sets the amount of free memory allocated for the pixel cache. Once this threshold is exceeded, all subsequent pixels cache operations are to/from disk.

Arguments

An integer number of megabytes.

Example

# set the cache threshold to 10Mb
Magick.set_cache_threshold(10)

Description

Establish a monitor exit block. Some (see below) RMagick methods will call the monitor event block, passing parameters that describe how much work there is to be done and how much of that work has already been accomplished.

There can be at most one monitor block defined at a time. To turn off monitoring, call Magick.set_monitor(nil).

Arguments

The argument is a Proc object. The Proc should accept 3 arguments:

text

a String that describes the operation being monitored.

quantum

a value between 0 and span that represents the number of events that have been performed, images that have been processed, etc.

span

The total number of events to be performed, images to be processed, etc.

Example

monitor = Proc.new { |text, quantum, span|
    printf("%s %3.0f%% complete\n", text, ((quantum/span.to_f)*100.0))
    }
Magick.set_monitor(monitor)

Magick API

SetMonitorHandler

Note

The list of methods which call the monitor block is difficult to determine. The only sure way to find out is to read the source code. In the Image class the list includes add_noise, blur_image, channel, chop, colorize, crop, colors, despeckle, enhance, equalize, flip, flop, frame, gamma_correct, implode, level, magnify, median_filter, minify, modulate, morph, negate, normalize, oil_paint, opaque, raise, reduce_noise, resize, roll, rotate, sample, scale, segment, shade, sharpen, shear, solarize, spread, stegano, stereo, swirl, texture threshold, transparent, and wave. In the ImageList class, the list includes append, average, and montage.