Image Processing Toolbox User's Guide Previous page   Next Page
iccread

Read ICC profile

Syntax

Description

P = iccread(filename) reads the International Color Consortium (ICC) color profile information from the file specified by filename. The file can be either an ICC profile file or a TIFF file containing an embedded ICC profile. To determine if a TIFF file contains an embedded ICC profile, use the imfinfo function to get information about the file and look for the ICCProfileOffset field.

iccread returns the profile information in the structure P, a 1-by-1 structure array whose fields contain the data structures (called tags) defined in the ICC specification. iccread can read profiles that conform with either Version 2 (ICC.1:2001-04) or Version 4 (ICC.1:2001-12) of the ICC specification. For more information about ICC profiles, visit the ICC web site, www.color.org.

ICC profiles provide color management systems with the information necessary to convert color data between native device color spaces and device independent color spaces, called the Profile Connection Space (PCS). You can use the profile as the source or destination profile with the makecform function to compute color space transformations.

The number of fields in P depends on the profile class (input, output, or display) and the choices made by the profile creator. iccread returns all the tags for a given profile, both public and private. Private tags and certain public tags are left as encoded uint8 data. The following table lists fields that are found in any profile structure generated by iccread, in the order they appear in the structure.

Field
Data Type
Description
Header
1-by-1 struct array
Profile header fields
TagTable
n-by-3 cell array
Profile tag table
Copyright
Text string
Profile copyright notice
Description
1-by-1 struct array
The Plain field in this structure contains a text string describing the profile.
MediaWhitepoint
double array
XYZ tristimulus values of the device's media white point
PrivateTags
m-by-2 cell array
Contents of all the private tags or tags not defined in the ICC specifications. The tag signatures are in the first column, and the contents of the tags are in the second column. Note that iccread leaves the contents of these tags in unsigned 8-bit encoding
Filename
Text string
Name of the file containing the profile

Additionally, P might contain one or more of the following transforms:

Notes

Portions of the implementation of iccwrite are derived from the RSA Data Security, Inc. MD5 Message-Digest Algorithm.

Example

The example reads the ICC profile that describes a typical PC computer monitor.

The profile header provides general information about the profile such as its class, color space, and PCS. For example, to determine the source color space, view the ColorSpace field in the Header structure.

See Also

applycform, iccwrite, isicc, makecform


Previous page  hsv2rgb iccwrite Next page

© 1994-2005 The MathWorks, Inc.