GRAY-LEVEL IMAGE CONTOURS EXTRACTION & COMPRESSION USING WAVELET TRANSFORM

This paper presents a method of contour extraction and compression from grey level image. Single step parallel contour extraction (SSPCE) method is used for the binary image after inverse wavelet transform is applied to the details images. Then the contours are compressed using either Ramer or Trapezoid methods in spatial domain. The proposed algorithms are applied in spectral domain using single-level wavelet transform (WT). Effectiveness of the contour extraction and compression for different classes of images is evaluated. In the paper the main idea of the proposed procedure for both contour extraction and image compression are performed. To compare the results, the mean square error, signal-to-noise ratio criterions, and compression ratio (bit per pixel) were used. The simplicity to obtain compressed image and extracted contours with accepted level of the reconstruction is the main advantage of the proposed algorithms.