FIELD-BASED UPSAMPLING METHOD FOR PERFORMING ZOOM IN A DIGITAL VIDEO SYSTEM

A video processing system that processes vertical column of pixels from individual fields is disclosed. The video processing system processes pixels from an even field independent of the pixels in the odd field, and vice versa. The video processing system preferably includes a system memory for storing fields of input video images and a vertical filter coupled to the system memory via a data bus. The field data is retrieved from the system memory by the vertical filter and processed as individual fields. The vertical filter preferably calculates a 2.times. enlargement of the input image, although the filter can be adapted to enlarge by different factors if desired. The enlargement process generally involves representing an input image with twice as many lines of pixels values as the initial image. The values that are used to represent the enlarged pixels are preferably weighted averages of the pixels from an input pixel field. The vertical filter calculates the weighted averages using coefficients that are based on the proximity of the resulting enlarged pixel values to the corresponding pixels from the input field.