SUMMARYInterpretation of geologic features from LANDSAT images is often hindered by lack of definition between the various rock and structural areas. Fortunately the digital nature of the basic information permits the application of computerized techniques to correct radiometric and atmospheric error as well as enhance the resolution of reflectance zones and boundaries. Effective enhancement methods range from simple arithmetic transforms, ratioing and data stretching to the application of linear inverse filters and process cascading. These techniques are effective for geological definition because they can be used to highlight specific features without degrading the total information content of the data.If the signal received by the LANDSAT sensors can be regarded as the multiplication of the illuminance by the reflectance, then another series of processing techniques can be used for image enhancement. The new processes are termed “Homomorphic” and can lead to more effective enhancement without many of t...