CIE 223

Abstract

Scope: Background Increasingly, colour imaging is being done with cameras capable of capturing more than three channels or bands. With its focus on promoting colour science, CIE Division 8 "Image Technology" established a technical committee on "Multispectral Image Formats" to address issues related to such imaging. For the purposes of this discussion, a multispectral image will be considered to be an image with more than three channels or bands of wavelengths. The visible wavelength range is the main concern, but the spectral channels may include bands in the ultraviolet or infrared. The term hyperspectral image is sometimes used, and a hyperspectral image is usually considered as having more channels (for example, more than 50) than a multispectral image. A hyperspectral image is often thought to be one that allows an almost continuous spectrum to be obtained without wavelength interpolation, but a continuous spectrum in each pixel can often be reconstructed from a multispectral image, as described in 3.4. However, the boundary between multispectral and hyperspectral is not accurately defined, so, in this technical report, multispectral and hyperspectral images are not distinguished and the term "multispectral" is used for simplicity. Furthermore, the term "spectral image" refers to a multispectral image, a hyperspectral image, or an image with reconstructed continuous spectra. This document deals with two-dimensional (planar) multispectral images only. Spectral imaging is found in many applications including medical imaging, document preservation, fashion design, automobile manufacturing, recycling, science, and remote sensing. It is desirable to have a common format that can be used to share spectral images between various users. Candidate formats include those already standardized by other organizations as well as native formats that are currently used by a ve ry select group of individuals or organizations. The scope of this report includes the study, development, and recommendation of encoding techniques and data formats for the exchange of multispectral images , as well as testing and evaluation.