Similarities and differences between multispectral and hyperspectral images

Similarity: Multi-spectrum and Hyperspectrum belong to one kind of spectral imaging technology and are widely used in the field of image processing.

1, different resolutions

Multispectral imaging-The spectral resolution is in the order of delta_lambda/lambda=0. 1. Generally, this kind of sensor has only a few bands in the visible and near infrared regions.

Hyperspectral imaging-the spectral resolution is in the order of δ_λ/λ= 0.0 1. This sensor has several to several hundred bands in visible and near infrared regions, and its spectral resolution can reach nm.

2. Different bands

Multispectral images usually refer to 3 to 10 band. Each band is obtained by using a remote sensing radiometer.

Hyperspectral images are composed of narrow bands (10-20 nm), and spectral images may have hundreds or thousands of bands. Generally speaking, it comes from an imaging spectrometer.

3, the principle is different

Hyperspectrum: Through hyperspectral sensors installed on different space platforms, that is, imaging spectrometers, the target area can be imaged simultaneously in the ultraviolet, visible, near-infrared and mid-infrared regions of the electromagnetic spectrum, and in dozens to hundreds of continuous and subdivided spectral bands.

Multi-spectrum: each band is a gray image, and the brightness of the scene is expressed according to the sensitivity of the sensor used to generate the band. In such an image, each pixel is associated with a number string, that is, a vector, in which the pixels are located in different bands. This string is called the spectral label of the pixel.

With the higher spectral details in hyperspectral images, we can see the invisible things better. For example, hyperspectral remote sensing, because of its high spectral resolution, is extracted between three minerals. However, the multi-spectral Landsat thematic imager cannot distinguish these three minerals.

Baidu Encyclopedia-Multispectral Images

Baidu Encyclopedia-Hyperspectral Images