Animated Color Cube

The RGB color model is framed by black, white, three additive primary colors, and three subtractive secondary colors, but there are many hues between them. We used a color cube for representing dimensional bases and intermediate hues and animated it to visualize color interpolation processes.

Demosaicing of RGBW Color Filter Array Based on Rank Minimization with Colorization Constraint

Recently, the white (w) channel has been incorporated in various forms into color filter arrays (CFAs). The advantage of using theWchannel is thatWpixels have less noise than red (R), green (G), or blue (B) (RGB) pixels; therefore, under low-light conditions, pixels with high fidelity can be obtained. However, RGBW CFAs normally suffer from spatial resolution degradation due to a smaller number of color pixels than in RGB CFAs. Therefore, even though the reconstructed colors have higher sensitivity, which results in larger Color Peak Signal-to-Noise Ratio (CPSNR) values, there are some color aliasing artifacts due to a low resolution. In this paper, we propose a rank minimization-based color interpolation method with a colorization constraint for the RGBW format with a large number ofWpixels. The rank minimization can achieve a broad interpolation and preserve the structure in the image, and it thereby eliminates the color artifacts. However, the colors fade from this global process. Therefore, we further incorporate a colorization constraint into the rank minimization process for the better reproduction of the colors. The experimental results show that the images can be reconstructed well, even from noisy pattern images obtained under low-light conditions.

Color Interpolation Algorithm for a Periodic White-Dominant RGBW Color Filter Array

Recently, CFA sensors including the W channel have been developed. Since the W channel receives luminance information, the W channel has a wider spectrum band than that of the R, G, and B channels. Therefore, the W channel can get higher SNR than that of the R, G, and B channels. There are many color interpolation methods for the Bayer CFA, but less for the RGBW CFA. In this paper, we propose a new color interpolation method for white-dominant RGBW CFA. The proposed method is edgeadaptive. Its method reconstruct the W channel first which has a high sampling rate. Next, the R, G, and B channels are reconstructed by using the color difference domains with theWchannel. Experimental results show that the PSNR and visual confirmation are higher than the conventional method.