The experience in the past years or image processing snows a tew geological information in the plain area. Conventional contrast enhancement gives monotonous hue that would not reflect geological subject properly. Authors suggest performance of enhancement at spectral dimensions. The nature of suggested technique is extension of the differences in the brightness values of named pixel at the three spectral dimensions which are involved in the composition that makes the named pixel more bright-colored

i.e color-enhanced. Such processing method changes the subtle differences between the brightness of the diverse objects in the image into obvious differences in the colors. The geological information can be enhanced in this way.Performance of spectral-dimension enhancement requires two terms. The first is that the brightness values of the named pixel must maintain the same relationship

i.e

the bigger value must be remained bigger after enhancement; the second

sum of the brightness values at the three dimensions must be remained the same as before enhancement

so that the only operation in the enhancement is extension of the differences in the brightnesses at three spectral bands. Therefore

the method provides the specifications of a standard false color composite and

simultaneously

a bright-colored

information-enriched image.