Read color filter array (CFA) image from RAW file
Read CFA Image Data from File
Read only the visible Color Filter Array (CFA) image data from a file. By default,
rawread returns only the visible portion of the CFA image.
cfa = rawread("colorCheckerTestImage.NEF");
Read the entire CFA image from a file, including the image frame. In a RAW image, the frame is typically used to calculate the black-level surrounding the visible image.
cfa = rawread("colorCheckerTestImage.NEF", "VisibleImageOnly", false);
filename — Name of RAW file
string scalar | character vector
Name of RAW file, specified as a string scalar or character vector. Specify
filename as a full path, containing the file name and extension,
or as a relative path from the current folder or from any folder on the MATLAB® path.
visibleImageOnly — Return only visible CFA image data
true (default) |
Return only visible CFA image data, specified as
false. In a RAW image, the frame is typically used to calculate the
black-level surrounding the visible image. To read only the visible portion of the CFA,
true. To read the entire CFA, including the frame, specify
false. This table provides more detail for each option.
The dimensions of the
The dimensions of the
cfaImage — CFA image
CFA image, returned as an m-by-n-by-p numeric array.
rawread returns only the visible portion of the CFA
image. In this case, the values of m and n
correspond to the first and second elements of the
field reported by
respectively. If you choose to include the frame in the returned image, then the values
of m and n correspond to the first and second
elements of the
CFAImageSize field reported by
rawinfo, respectively. For both types of returned images, the
value of p depends on the type of CFA sensor. For Bayer type sensors,
the value is 1. For a Foveon sensor, the value is 3.
RAW File Format
The RAW file format preserves image data in its most unedited state, recorded directly from the camera sensor. Most camera manufacturers define their own proprietary RAW file format, such as the Nikon NEF file format and the Canon CRW format. Adobe has also defined a RAW file format, DNG (digital negative), which is supported by several cameras. The name of the format is typically capitalized, like other file formats such as JPG and TIF. However, unlike other file formats, RAW is not an acronym.
The function uses LibRaw version 0.20.2 for reading the CFA image data.
rawreadfunction does not support RAW file formats that employ JPEG compression.
Run code in the background using MATLAB®
backgroundPool or accelerate code with Parallel Computing Toolbox™
This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.
Version HistoryIntroduced in R2021a
R2022b: Support for thread-based environments
rawread now supports thread-based