Dynamic range refers to the range of brightness levels, from dark to light. The dynamic range of real-world scenes can be quite high. High dynamic range (HDR) images attempt to capture the whole tonal range of real-world scenes (called scene-referred), using 32-bit floating-point values to store each color channel. HDR images contain a high level of detail, close to the range of human vision. The toolbox includes functions for reading, creating, and writing HDR images, and a tone-map operator for displaying HDR images on a computer monitor.
To read a high dynamic range image into the MATLAB® workspace, use the
hdr_image = hdrread('office.hdr');
The output image
hdr_image is an
m-by-n-by-3 image of type
Name Size Bytes Class Attributes hdr_image 665x1000x3 7980000 single
Note, however, that before you can display a high dynamic range image, you must convert it to a dynamic range appropriate to a computer display, a process called tone mapping. Tone mapping algorithms scale the dynamic range down while attempting to preserve the appearance of the original image. For more information, see Display High Dynamic Range Image.
To create a high dynamic range image from a group of low dynamic range images, use the
makehdr function. Note that the low dynamic
range images must be spatially registered and the image files must contain EXIF metadata.
Specify the low-dynamic range images in a cell array.
hdr_image = makehdr(files);
To write a high dynamic range image from the MATLAB workspace into a file, use the