Digital video signal code size control apparatus

Claim 1

A digital video signal code size control apparatus for encoding a signal, comprising: field memory means for storing at least a field of said video signal; high frequency component measuring means for measuring a high frequency component strength of an image carried in said video signal, the high frequency component measuring means including: pixel memory means for storing a predetermined number of consecutive pixels; weighting means for weighting said pixels stored in said pixel memory means by a plurality of predetermined weighting values and for producing weighted values; adding means for adding said weighted values and for producing a sum; quantization parameter generation means for generating selected quantization parameters, prior to encoding said video signal, based on said high frequency component strength; and coding means for encoding said video signal in said field memory means using said selected quantization parameters to generate coded video signal of one field within a preselected data length, wherein said quantization parameter generation means comprises a look-up table memory carrying a plurality of look-up tables, each table containing a plurality of quantization parameters P ij in a matrix format in which i represents a column and j represents a row, said high frequency component strength being used as an address for selecting a look-up table.