Abstract: A shape adaptive wavelet transform is performed on a digitized image signal representing an image. First, a shape information is obtained about the image, and the shape information is applied to a shape adaptive wavelet filter. The shape adaptive wavelet filter detects a starting point and an ending point of the image. The digitized image signal is divided into a low-frequency component and a high-frequency component. Then each frequency component is sampled, using the shape information. The shape adaptive wavelet filter then generates converted shape information indicating the shape for each sampled frequency component.