Image coloring Techniques and Applications

Doctoral Thesis / Dissertation from the year 2011 in the subject Computer Science - Miscellaneous, Minufiya University (Faculty of Computers and Information), language: English, abstract: After the appearance of Image Colorization in the literature and the different developments of colorization techniques, it was necessary to search for new applications for this new field rather than coloring gray images. This thesis is a research and implementation study for various applications that can exploit from colorization techniques. Three proposed colorization applications are proposed in this thesis; Automatic Movie Colorization System, Color Image Encoding System Using HSI Space Embedding System and Color Image Encoding System Using Morphological Decolorization. The first application of image colorization attracts researchers in this field is Old Movies Colorizing. This thesis presents a new proposal for a system that works on coloring the old movies automatically. The proposed system is based on coloring the film shot by shot instead of frames as it is common in this area. This is done by splitting the film into shots and coloring the first frame in the shot (the key frame) . After that the motion vector between the frames of each shot is generated to transfer the colors from the key frame to the following frames in the shot using the motion vector.

Color image encoding becomes an important application for image colorization. The idea is to remove colors from color images at the sender side while retaining the information about colors to enable image recolorization at the receiver side. The reason behind this methodology is to exploit from the smaller size of gray images. At

the receiver side, the colors are restored and the images are recolored. This Methodology of encoding is called Image Decolorization. The thesis presents two different approaches to color images decolorization: Color Embedding and Automatically Color Seeds Selection. A new system to compress the color channels in the color model "Hue, Saturation and Intensity" (HSI) is proposed. The encoded chromatic channels are hided inside the lighting channel using the ¿Least Significant Bit ¿(LSB) method. This is done by converting the Hue channel into objects and then to be encoded by an Object Compression method. For Saturation channel, there are two methods to compress S channel are proposed; "the Minimum Color Difference" (MCD) and "Y(Luma) Intensity Difference"(YID). The third proposed system is

a new automatic color seeds selection method based on Morphology . The seeds are extracted from the inner boundaries of image objects and hided in the luminance channel using LSB method.