Gradient adaptive video de-interlacing

A method comprising:

• receiving a sequence of interlaced video signal fields, said sequence including a first field, a second field which immediately follows the first field in said sequence, and a third field which immediately follows the second field in said sequence;
• applying an initial de-interlacing procedure to said first field, second and third fields;
• performing motion estimation with respect to one of said first, second and third fields to determine motion vectors for said one of said first, second and third fields, said motion estimation including comparing at least one pixel in said first field with at least one pixel in said third field;
• and
• performing motion-compensated de-interlacing on said one of said first, second and third fields using the motion vectors determined by said motion estimation.

An apparatus comprising:

• a storage medium having stored thereon instructions that when executed by a machine result in the following:
• determining a lowest-score interpolation direction among a plurality of interpolation directions;
• calculating a candidate pixel value by interpolating along said lowest-score interpolation direction;
• and
• applying a median function to a set of pixel values that includes:
• (a) said candidate pixel value;
• (b) at least one pixel value from a line of pixels that is immediately above a pixel location that is currently being interpolated;
• and
• (c) at least one pixel value from a line of pixel values that is immediately below said pixel location that is currently being interpolated.

A system comprising:

• a tuner;
• and
• a de-interlacing circuit coupled to the tuner and operative to:
• determine a lowest-score interpolation direction among a plurality of interpolation directions;
• calculate a candidate pixel value by interpolating along said lowest-score interpolation direction;
• and
• apply a median function to a set of pixel values that includes:
• (a) said candidate pixel value;
• (b) at least one pixel value from a line of pixels that is immediately above a pixel location that is currently being interpolated;
• and
• (c) at least one pixel value from a line of pixel values that is immediately below said pixel location that is currently being interpolated.