The effect of reduced color depth on the color reproduction of web images

Abstract

Accurate color reproduction of images viewed across the Internet can be a difficult task due to problems,which include variable viewing conditions.The standard RGB color space (sRGB)has been proposed to overcome this problem without the need for special software applications. Different graphics adapter bit-depth settings also affect the number of displayable colors on a web browser.For this reason,the 216 colors "web safe" palette has been introduced. To understand the effect of device characteristics on the process of image reproduction via the web,the characterization of some common devices was carried out. This created a controlled environment whereby experiments could be conducted with reproducible results.Device characterization also enabled the accurate conversion of scanned images to sRGB by using a step-by-step process that followed the specification of the color space. The investigation of color reproduction on a Cathode Ray Tube (CRT)display under different bit-depth settings has been conducted using a suitable test target,which was converted to the sRGB color space and also to the "web safe"(216 colors)palette.These two images were displayed under the 8-bit and 24-bit depth settings of the graphics card adaptor. Colorimetric measurements concerning color differences were performed and evaluated.Experimental investigation on the true color (24-bit color depth)image while displayed under 8-bit setting via different browsers followed.The outcome of the investigations was evaluated and combined to determine the relationship between the different parameters described above and their effect on image quality