Edge enhancement of remote sensing image data in the DCT domain

Edge Enhancement is an important image processing method for remote sensing image data. Many images are compressed by JPEG standard which uses the Discrete Cosine Transform (DCT). Manipulating data in the DCT domain is an efficient way to save the computer resources. In this paper, new algorithms for edge enhancement of remote sensing image data in the DCT domain are developed and implemented in three steps: highpass filtering, adding back full or part of gray levels to the original image, and linear contrast stretching. In addition, a method to approximate the minimum (MIN) and maximum (MAX) gray level intensity is presented in the paper, which are the necessary information for contrast stretching. Experimental results show that the quality of images generated by the new algorithms are comparable with that of images generated by the corresponding methods in the spatial domain.

[1]  R. J. Clarke,et al.  Lowpass filtering in the cosine transform domain , 1980 .

[2]  Bo Shen,et al.  Scanline algorithms in compressed domain , 1996, Electronic Imaging.

[3]  Byeong Gi Lee,et al.  Transform domain filtering based on pipelining structure , 1992, IEEE Trans. Signal Process..

[4]  Lawrence A. Rowe,et al.  Algorithms for manipulating compressed images , 1993, IEEE Computer Graphics and Applications.

[5]  Bo Shen,et al.  Direct feature extraction from compressed images , 1996, Electronic Imaging.

[6]  K. R. Rao,et al.  Discrete cosine transform filtering , 1990, International Conference on Acoustics, Speech, and Signal Processing.

[7]  Shih-Fu Chang,et al.  Manipulation and Compositing of MC-DCT Compressed Video , 1995, IEEE J. Sel. Areas Commun..

[8]  Shih-Fu Chang,et al.  New algorithms for processing images in the transform-compressed domain , 1995, Other Conferences.

[9]  T. M. Lillesand,et al.  Remote sensing and image interpretation. Second edition , 1987 .

[10]  Bo Shen,et al.  Inner-block operations on compressed images , 1995, MULTIMEDIA '95.

[11]  Shih-Fu Chang,et al.  Compressed-domain techniques for image/video indexing and manipulation , 1995, Proceedings., International Conference on Image Processing.