Lossless image compression based on data folding Yerva, S.; Nair, S.; Kutty, K.
2011 International Conference on Recent Trends in Information Technology (ICRTIT),
2011-June
Conference Proceeding
The paper presents an approach for lossless image compression in spatial domain for continuous-tone images using a novel concept of image folding. The proposed method uses the property of adjacent ...neighbor redundancy for prediction. In this method, column folding followed by row folding is applied iteratively on the image till the image size reduces to a smaller pre-defined value. For column folding, elements of even columns are subtracted from elements of odd columns. Thereafter, row folding is applied on odd columns in a similar fashion. In row folding, even rows are subtracted from odd rows and the resultant odd rows are used for next iteration. The difference data, thus obtained, is stored in a tile format; which along with the reduced image is encoded and transmitted. The proposed method is compared with the existing standard lossless image compression algorithms and the results show comparative performance. Data folding technique is a simple approach for compression that provides good compression efficiency and has lower computational complexity as compared to the standard SPIHT technique for lossless compression.
Fisheye cameras are widely used in various applications like surveillance, robotic vision, automobile rear-view imaging systems etc. But the images captured by fisheye lens are hemispherical and ...objects away from the center of image look curved due to lens distortion. Hence it is a challenge for an end user to interpret the data correctly from these images. The solution lies in digitally processing these images to obtain distortion-free rectilinear images. The process should compensate for both fish eye and perspective distortions with minimum overhead. This paper presents a novel approach that corrects fisheye and perspective distortions from wide angle camera image. The basic geometry of hyperbola is used for fisheye correction; while perspective correction is done using a standard homography based transform. Both these correction techniques are combined to form a mapping matrix wherein each output pixel in the corrected image is related to the corresponding pixel in the input distorted image. This approach using a mapping matrix reduces the overall processing time and hence can be extended for video correction. This method finds application in vision based parking assist system; in order to provide a perspective view of the parking area from the input wide angle images.
Since their first description, liposomes have been put to a wide variety of uses. Encapsulation or incorporation of antigens into liposomes markedly enhances the immunogenicity of the antigen. The ...type of immune response elicited by the liposome is found to depend on their chemical and structural properties. Immunization with viral glycoproteins encapsulated in liposomes has resulted in enhancement of the humoral response seen as a rise in the serum antibody levels which is several fold higher than that elicited by free antigen alone. Furthermore, liposome encapsulation of peptide antigens which are poor immunogens by themselves not only increases the immunogenicity of the peptide but also play an important role in delivery. The adjuvant effect afforded by liposomes can be further enhanced by the concomitant encapsulation of adjuvants like lipid A or muramyl tripeptide-phosphatidylethanolamine. Formation of liposomes with special characteristics such as pH sensitivity has resulted in the use of liposomes to deliver soluble antigen to the cytosol where it can undergo class I pathway of processing and presentation. Therefore liposomes could provide valuable tools to further understand the pathways of antigen processing and the requirements for induction of cell mediated immunity.
