Method and apparatus for upscaling video images when pixel data used for upscaling a source video image are unavailable

A computer system for displaying a source video image comprising a one scan line and an another scan line represented by a set of source video pixel data, the computer system comprising:

• a display unit for displaying an upscaled video image corresponding to the source video image;
• a display memory for storing the set of source video pixel data;
• and
• a graphics controller circuit for generating display signals to said display unit, said graphics controller circuit further comprising:
• a host interface for receiving the set of source video pixel data from said display memory;
• an interpolator generating a set of additional pixel data comprised in the upscaled video image by interpolating the source video pixel data of the one scan line and the another scan line;
• a first circuit for determining a condition in which at least one of the source video pixel data of the another scan line are unavailable for interpolation by said interpolator;
• and
• a control circuit to cause said interpolator to generate the set of additional pixel data from the source video pixel data of only the one scan line when the source video pixel data of the another scan line are unavailable.

A method of upscaling a source video image to generate an upscaled video image, wherein the source video image comprises at least a one scan line and an another scan line represented by a set of source video pixel data, the method comprising the steps of:

• generating a set of additional pixel data comprised in the upscaled video image by interpolating the source video pixel data of the one scan line and the another scan line;
• determining whether at least one of the source video pixel data of the another scan line are unavailable to said step of generating a set of additional pixel data;
• and
• generating the set of additional pixel data from the source video pixel data of only the one scan line when the source video pixel data of the another scan line are unavailable.