Image enhancement is the process of adjusting digital images so that the results are more suitable for display or further image analysis. For example, you can remove noise, sharpen, or brighten an image, making it easier to identify key features.
Image improvement is the procedure for enhancing the quality and informative content of the original data before processing. Common practices include contrast enhancement, spatial filtering, density slicing, and FCC. The improvement or stretching of the contrast is carried out by the linear transformation of the gray level of the original range. Spatial filtering is mostly natural linear characteristics such as faults, shear zones and lineaments. Density slicing converts a series of density intervals into a series of gray tones with a different color or symbol to represent different characteristics.
The FCC is more commonly used in remote sensing compared to real colors due to the absence of a pure blue band because of the greater wavelength of the dominant blue wavelength. The FCC is standardized because it provides maximum identification information on the earth and satisfies all users. In the standard FCC, the vegetation looks red because the vegetation is very reflective in the NIR and the applied color is red. Bodies of water appear dark if they are clear or deep because IR is an absorption band for water. Bodies of water depend on the blue of the shades, or their shallow depth, because the water of these bodies is reflected in the green wavelength and the color applied.