False Color Composite Display of Mulitband Images on Personal Computer using Cubic Color Block Technique
Jitkasame Ngarmnil, Sujate Jantarung
Faculty of Engineering, Mahanakorn College
Nongjok, Bangkok 10530, Thailand
Fusak Cheevasuvit, Kobchiai Dejhan
Faculty of Engineering
King Mongkut's Institute of Technology Ladkrabang
Bangkok 10520, Thailand
Abstract
A display technique for false color composite multiband images via the video graphic array (VGA) on personal computer is presented. Since the reflectance's in all band of satellite images are considered as equally importance information. Therefore, to avoid the emphasis of any band image, the cubic color block technique is applied to obtain the almost equally colors shades of three band images. The ratio of three color shades I 7:6:6 for 252 distinct color which is not exceeded the 256 color register index of VGS system. The result shows a colorful image which is not too much different when compared with the expensive computer system.
Introduction
The progress of VLSI makes the personal computer more powerful and cheaper, therefore more and more researchers in Remote Sensing field try to use it for processing and displaying the result in the form of color image. The most to popular of color graphic system for personal computer is vide graphic array (VGA). This graphic system has three color registers for red, green and blue. The capacity of each color register is 6 bits which can provide for 64 distinct color shades. Therefore, the VGS system has 218 distinct colors 218 distinct colors, because of its limitation of the capacity of color index register which is 8 bits. Therefore, it can simultaneously display 256 distinct colors. The problem is arised that who to select the 256 proper colors for displaying the false color composite image. in general, many researchers solved this problem by dividing the 8 bits of color index register as 3:3:2 bits (or 8:8:4 colors) for color register of red, green and blue, respectively. By this combination, there is an emphasis on the first two images, and the third image is considered as least important information. This will be contradicted tot eh concept of displaying information. This will be contradicted to the concept of displaying false color image. since the false color image is composed from multiband images and it is used for interpretation of mulitspectral classification. As we know that each pixel in a satellite image is recorded at many different wavelengths bands. A pixel may be characterized by it spectral signature, which is determined by the multispectral classification is an information extraction process that analysis the spectral signatures and then assign pixels to multi band images are considered as equally important information's for image classification. By this reason this paper presents a cubic color blocks technique for dividing the 8 bits of color register
index as an almost equally color shades for each color as mentioned in the next section.
