ImageMagick: Command-line Tools: Stream
Author: ImageMagick Studio LLC
Description: ImageMagick (TM) is a free software suite to create, edit and compose bitmap images. It can read, convert and write images in a large variety of formats. Images can be cropped, colors can be changed, various effects can be applied, images can be rotated and combined, and text, lines, polygons, ellipses and Bézier curves can be added to images and stretched and rotated. ImageMagick is free software: it is delivered with full source code and can be freely used, copied, modified and distributed. Its license is compatible with the GPL. It runs on all major operating systems. Most of the functionality of ImageMagick can be used interactively from the command line; more often, however, the features are used from programs written in the programming languages Perl, C, C++, Python, PHP, Ruby or Java, for which ready-made ImageMagick interfaces (PerlMagick, Magick++, PythonMagick, MagickWand for PHP, RubyMagick, and JMagick) are available. This makes it possible to modify or create images automa [cell cut: 1159 characters, first 1000 kept]
Keywords: command-line, tools:, stream, ImageMagick, PerlMagick, Magick++, Image, Magick

`Stream` is a lightweight tool to stream one or more pixel components of the image or portion of the image to your choice of storage formats. It writes the pixel components as they are read from the input image a row at a time making `stream` desirable when working with large images or when you require raw pixel components. ## Example Usage We list a few examples of the `stream` command here to illustrate its usefulness and ease of use. To get started, lets stream the red, green, blue components of a 640x480 JPEG image to disk as unsigned characters:
      stream -map rgb -storage-type char image.jpg pixels.dat
      display -depth 8 -size 640x480 rgb:pixels.dat
Here we extract a 100x100 region from a TIFF image in the grayscale format as doubles:
      stream -map i -storage-type double -extract 100x100+30+40 image.tif gray.raw
You can also associate the region to extract with the image filename:
      stream -map i -storage-type double 'image.tif[100x100+30+40]' gray.raw
## Option Summary The `stream` command recognizes these options. Click on an option to get more details about how that option works.
Option | Description
--- | ---
-authenticate value | decrypt image with this password
-channel type | apply option to select image channels
-colorspace type | set image colorspace
-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
-extract geometry | extract area from image
-help | print program options
-interlace type | type of image interlacing scheme
-limit type value | pixel cache resource limit
-list type | Color, Configure, Delegate, Format, Magic, Module, Resource, or Type
-log format | format of debugging information
-map components | store pixels in this format.
-monitor | monitor progress
-quantize colorspace | reduce colors in this colorspace
-quiet | suppress all error or warning messages
-regard-warnings | pay attention to warning messages.
-sampling-factor geometry | horizontal and vertical sampling factor
-set attribute value | set an image attribute
-size geometry | width and height of image
-storage-type type | store pixels with this storage type.
-verbose | print detailed information about the image
-version | print version information
-virtual-pixel method | access method for pixels outside the boundaries of the image

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