Method and apparatus for de-interlacing video fields for superior edge preservation

A computer implemented method of interpolating a desired pixel between scan lines, said method comprising the steps of:

• selecting a minimal variance direction between
• a first direction comprising a first pixel above and to the left of the desired pixel and a second pixel below and to the right of the desired pixel,
• a second direction comprising a third pixel above the desired pixel and a fourth pixel below the desired pixel, and
• a third direction comprising a fifth pixel above and to the right of the desired pixel and a sixth pixel below and to the left of the desired pixel,
• selecting the two pixels comprising the minimal variance direction as a minimal variance above pixel and a minimal variance below pixel;
• and
• selecting the median pixel of the minimal variance above pixel, the minimal variance below pixel, and a pixel from the previous video field having same position of the desired pixel.

An apparatus for line-doubling, said apparatus comprising:

• a previous video field memory, said previous field memory storing a first plurality of pixels from a previous video field;
• a current video field memory, said current field memory storing a second plurality of pixels from a current video field;
• and
• a median pixel selector, said median pixel selecting a median pixel from a first pixel in said current video field memory above and to the left of a desired pixel, a second pixel in said current video field memory above the desired pixel, a third pixel in said current video field memory above and to the right of the desired pixel, a fourth in said current video field memory pixel below and to the left of the desired pixel, a fifth pixel in said current video field memory below the desired pixel, a sixth pixel in said current video field memory below and to the right of the desired pixel, and a seventh pixel in the previous video field memory having same position of the desired pixel.

An apparatus for line-doubling, said apparatus comprising:

• a previous video field memory, said previous field memory storing a first plurality of pixels from a previous video field;
• a current video field memory, said current field memory storing a second plurality of pixels from a current video field;
• and
• a minimal variance selector, said minimal variance selector selecting a minimal variance above pixel and a minimal variance below pixel comprising from a minimal variance direction between
• a first direction comprising a first pixel above and to the left of the desired pixel and a second pixel below and to the right of a desired pixel,
• a second direction comprising a third pixel above the desired pixel and a fourth pixel below the desired pixel, and
• a third direction comprising a fifth pixel above and to the right of the desired pixel and a sixth pixel below and to the left of the desired pixel;
• and
• a median pixel selector, said median pixel selecting a median pixel from the minimal variance above pixel, the minimal variance below pixel, and a pixel from the previous video field having same position of the desired pixel.