Abstract: A transport stream TSd generated from a digital broadcast signal and a transport stream TSa generated from an analog broadcast signal are recorded simultaneously and a portion of TSd wherein the reception state of the digital broadcast is bad is replaced with TSa corresponding to the defective portion for compensation. A composite TS consisting of good TSd and TSa corresponding to defective TSd 102 is formed and recorded.

Abstract: A cochannel interference filter for a HDTV transmission system comprising a post-comb filter. The post-comb filter comprises first and second feedforward circuits. The first feedforward circuit includes a first adder and a first delay circuit. The first adder has a first input connected to an output of a data clock recovery circuit. The first delay circuit has an input connected to the output of the data clock recovery circuit and an output connected to a second input of the first adder. The second feedforward circuit includes a second adder and a second delay circuit. The second adder has a first input connected to an output of the first adder. The second delay circuit has an input connected to the output of the first adder and an output connected to a second input of the second adder. Also, the post-comb filter comprises third and fourth feedforward circuits. The third feedforward circuit includes a third adder and a third delay circuit.

Abstract: A Standard identification circuit has a capacitor that is gradually charged in a constant progression direction if the Standard is appropriate and in a reverse progression direction when the voltage across the capacitor reaches a low threshold. The circuit operates symmetrically (the charging and discharging currents of the capacitor have equal value) when the voltage across the capacitor is lower than an intermediate threshold, and operates asymmetrically (the discharging current is higher than the charging current) when the voltage is higher than the intermediate threshold.

Abstract: For deriving a keying signal for a video mixer from a video pattern signal which may be derived by reference to the presence of a selected color in one of the video signals to be mixed, the level-shift voltage added to the video signal for producing the clipped video pattern signal, instead of being constant, is derived from at least one amplitude envelope signal produced from the video signal in order to overcome effects of non-uniform lighting or shadow effects in the picture that contains a selected color. The clip voltage is about half of the amplitude envelope signal. Preferably, both positive and negative amplitude envelope signals are generated and the level-shift voltage is then the mean value of the voltages contemporaneously represented by the envelope signals. The envelope signals are stored for a picture field interval before being used to generate the level-shift voltage.

Abstract: A reproduction system noise reduction circuit of a VTR is implemented in combination with a recursive type noise reduction circuit and a non-recursive type noise reduction circuit. The recursive type noise reduction circuit has a characteristic complimentary to that of a recording system vertical emphasis circuit to function as a vertical de-emphasis circuit subjecting a reproduced luminance signal to vertical de-emphasis. The non-recursive type noise reduction circuit cancels noise components without line correlation from the reproduced luminance signal subjected to vertical de-emphasis. It is not necessary to increase noise reduction amount in each noise reduction circuit because vertical de-emphasis and noise reduction are carried out individually. Therefore, degradation of vertical resolution and increase in raining-like noise are prevented.

Abstract: A pyramidal coding circuit comprises a decimation circuit (14.1) which receives the picture consisting of M.times.N pixels to be transmitted and converts it into K+1 auxiliary pictures B.sub.k, the numbers of horizontal and vertical pixels of B.sub.k being smaller by respective factors A.sub.H and A.sub.V than those of the auxiliary picture B.sub.k-1 (k=0, 1, 2, . . . K) preceding in ordinal number. Each auxiliary picture B.sub.k is expanded in an expansion channel 14.4(.) to an expanded auxiliary picture B'.sub.k having the same number of horizontal and vertical pixels as the auxiliary picture B.sub.k-1. In a difference picture former 14.7 (.) the auxiliary picture B.sub.k-1 and the expanded auxiliary picture B'.sub.k having the same number of horizontal and vertical pixels as B.sub.k-1 are subtracted from each other for generating a difference picture D.sub.k-1. The expansion channel has not only a two-dimensional interpolating low-pass filtering function 14.5(.) but also a picture prediction function 14.

Abstract: A method of processing a foreground array of sample values, a background array of sample values and a crop array of sample values, which three arrays are coextensive and wherein the crop array represents a geometrical figure associated with a non-zero multiplication factor surrounded by a marginal area associated with a zero multiplication factor, comprises selecting a low-pass filtering operation to be carried out on the foreground array, and modifying the crop array so that when the selected low-pass filtering operation is carried out on the modified crop array, the sample values at the periphery of the domain of the resulting filtered crop array are all associated with a zero multiplication factor. The selected low-pass filtering operation is carried out on the foreground array and the modified crop array to provide a filtered foreground array and a filtered crop array respectively. The background array and the filtered foreground array are combined under control of the filtered crop array.