Scaling images for display

A structure for scaling a high definition television image that has pixels arranged in rows and columns, comprising:

• a memory operable to store the high definition television image;
• a first element configured to read X locations in the memory at an image update rate to fetch X horizontal pixel segments of the image, X being an integer greater than one, the fetched X horizontal pixel segments being vertically contiguous in the image, the first element being operable to vertically scale the X horizontal pixel segments at the image update rate, each horizontal pixel segment comprising a set number of contiguous pixels in a row of the image, each row comprising multiple horizontal pixel segments, the first element producing a vertically scaled horizontal pixel segment having the same number of pixels as one of the original fetched horizontal pixel segments, said first element repeating said vertical scaling for other sets of X horizontal pixel segments without overlap from top to bottom and from a left column to a right column of the image to form a vertically scaled image of contiguous, vertically scaled, horizontal pixel segments, the first element storing the image of contiguous, vertically scaled, horizontal pixel segments in the memory;
• a second element configured to read the vertically scaled, horizontal pixel segments from the memory at an image display rate and horizontally scale each vertically scaled horizontal pixel segment of the scaled image at the image display rate to form a pixel of a final two-dimensional scaled image, where said fetching, vertical scaling, storing and horizontal scaling uses a memory bandwidth of less than 200 megabytes per second;
• and
• a computer monitor operable to display the final two-dimensional scaled image.

An article comprising a computer-readable medium which stores computer-executable instructions for scaling each high definition television image that appears in a video sequence of images for display on a computer monitor that displays downscaled images, the instructions causing a computer to:

• store the high definition television image in a memory;
• read X locations in the memory at an image update rate to fetch X horizontal pixel segments of the image, X being an integer greater than one, the fetched X horizontal pixel segments being vertically contiguous in the image;
• vertically scale the X horizontal pixel segments at the image update rate, each horizontal pixel segment comprising a set number of contiguous pixels in a row of the image, each row comprising multiple horizontal pixel segments, the vertical scaling of the X horizontal pixel segments producing a vertically scaled horizontal pixel segment having the same number of pixels as one of the original fetched horizontal pixel segments;
• repeat said vertical scaling for other sets of X horizontal pixel segments without overlap from top to bottom and from a left column to a right column of the image to form a vertically scaled image of contiguous, vertically scaled, horizontal pixel segments;
• store the image of contiguous, vertically scaled, horizontal pixel segments in the memory;
• read the vertically scaled, horizontal pixel segments from the memory at an image display rate;
• horizontally scale each vertically scaled horizontal pixel segment of the scaled image at the image display rate to form a pixel of a final two-dimensional scaled image, where said fetching, vertical scaling, storing and horizontal scaling uses a memory bandwidth of less than 200 megabytes per second;
• and
• display the final two-dimensional scaled image on a computer monitor.