Low cost scan converter for television receiver
AssigneePhilips Electronics North America Corporation
InventorJohn E. Dean
Life of this patent
Estimating the term…
Abstract
A circuit that is easily configured to convert from a progressive scan image, e.g., at a resolution of 1280.times.720, to an interlaced image scan, e.g., at an interlaced resolution of 1920.times.1080 (1920.times.540 per field), or visa-versa. One arrangement of the circuit employs multiplexers so that the two conversion modes share the available hardware. The circuit is only marginally more complex than a circuit that can only do the conversion in one direction. The quality of the progressive-to-interlace conversion is acceptable for high-end interlaced display systems and the quality of the interlace-to-progressive conversion is at least high enough for "mid-range" progressive display systems.
Claims24
Apparatus for use in converting an interlace image field to a progressive image field and vice versa, the apparatus comprising:
- a vertical filter;
- a separate horizontal filter;
- and
- means for routing an input signal first to said vertical filter and the output therefrom to said horizontal filter when said input signal is to be converted from interlace to progressive and for routing said input signal first to said horizontal filter and the output therefrom to said vertical filter when said input signal is to be converted from progressive to interlace, without using an interlacer or linear interpolator before said vertical and horizontal filters.
Apparatus for horizontal and vertical multi-tap filtering, comprising:
- a vertical filter;
- a separate horizontal filter;
- and
- a plurality of multiplexers arranged to route an input signal first to said vertical filter and the output therefrom to said horizontal filter when said input signal is to be horizontally decimated to a lower resolution and vertically interpolated to a higher resolution and for routing said input signal first to said horizontal filter and the output therefrom to said vertical filter when said input signal is to be horizontally interpolated to a higher resolution and vertically decimated to a lower resolution, without using an interlacer or linear interpolator before said vertical and horizontal filters.
Apparatus for horizontal and vertical multi-tap filtering, comprising:
- a vertical filter including (i) a plurality of line memories, (ii) a first coefficient store, (iii) a plurality of first multipliers, and (iv) a first adder having a plurality of inputs, each of said first multipliers being arranged to multiply an output of a respective one of said line memories by a coefficient stored in said first coefficient store, the resulting products being coupled to said first adder for summation thereby;
- a separate horizontal filter including (i) a plurality of single element storage units, (ii) a second coefficient store, (iii) a plurality of second multipliers, and (iv) a second adder having a plurality of inputs, each of said second multipliers being arranged to multiply an output of a respective one of said single element storage units by a coefficient stored in said second coefficient store, the resulting products being coupled to said second adder for summation thereby;
- and
- a plurality of multiplexers arranged to route an input signal first to said vertical filter and the output therefrom to said horizontal filter when said input signal is to be horizontally decimated to a lower resolution and vertically interpolated to a higher resolution and for routing said input signal first to said horizontal filter and the output therefrom to said vertical filter when said input signal is to be horizontally interpolated to a higher resolution and vertically decimated to a lower resolution, without using an interlacer or linear interpolation before said vertical and horizontal filters.
Apparatus for horizontal and vertical multi-tap filtering an input signal, comprising:
- means for vertical filtering;
- separate means for horizontal filtering;
- and
- means for routing said input signal first to said means for vertical filtering and the output therefrom to said means for horizontal filtering when said input signal is to be horizontally decimated to a lower resolution and vertically interpolated to a higher resolution and for routing said input signal first to said means for horizontal filtering and the output therefrom to said means for vertical filtering when said input signal is to be horizontally interpolated to a higher resolution and vertically decimated to a lower resolution, without using an interlacer or linear interpolatior before said vertical and horizontal filters.
Dependencies are inferred from the claim text.