Method and circuit for zooming digital video image based on dual quadratic interpolation

The method and circuit executes following operations: under action of input line-field signal, writing digital video data in 24 bits YUV format or RGB format into data memory; then using modulation of the input line-field signal generation generates the output line-field signal; under action of the output line-field signal, accumulated mapping calculation of scaling factor generates the reading address of the data read-out memory; using weighting calculation for read-out data obtains interpolated data. Features are: simple circuit and cubic interpolation, and few hardware resources. Being as independent IP kernel, the invention can be applied to each occasion needed to scale video image.