| 摘要 |
The present invention relates to a method and apparatus for compressing digital data, such as the digital representation of a colored image. A scanning routine is described which aims to maintain the integrity of regions of the image that the human visual system also finds important. Pixel data from the image data includes color components, e.g., intensities of three or more colors such as red, green and blue or cyan, magenta and yellow. When the color components of the pixels are represented in color space, the axes of which are the three color components with the intensities thereof as variables, it has been found experimentally, particularly for artificial or synthetic images, that significant regions in the image tend to produce clusters of points in color space. In accordance with the invention, the color space is scanned by a space filling curve to convert the coordinates in color space into a one dimensional matrix such as a histogram. If certain types of space filling curves are used, e.g., a step-wise curve such as the Peano or Hilbert fractal, the clusters of points in color space tend to produce clusters of points in the histogram. Having obtained the histogram, it is segmented into a series of bins. These bins are used to segment the original image into regions which are coded. Although the invention has been described with respect to color images and 3-D color space, the method and apparatus may be useful with other types of data and with multidimensional spaces.
|
