JPH01166684A - Moving vector detection circuit - Google Patents

Abstract

PURPOSE:To expand the detection range of a moving vector by adding plural frame differences, detecting a minimum value, calculating an offset in horizontal and vertical directions from the result and controlling a representative point setting section and a switch. CONSTITUTION:An output of the representative point setting section 2 connected to a frame memory 1 and subject to offset control and a preceding frame are subtracted by a subtractor 3 and the difference is added (4) by number of representative points. A minimum value of the sum of frame differences is detected (5) to detect a minimum value Vx and Vy of the moving vector in horizontal and vertical directions and to calculate an offset of the moving vector in horizontal and vertical directions thereby controlling the representative point setting section 2 and switches 6, 9 via horizontal and vertical offset control sections 11, 12. Moreover, values from offset devices 7, 10 and the minimum values Vx, Vy are added (8) to form horizontal and vertical moving vectors. Thus, the detection enable range of the moving vector is expanded rapidly.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a motion vector detection circuit for an image signal.
In particular, the present invention relates to a motion vector detection circuit having a function of easily expanding the detectable range of motion vectors by providing a positional offset value to an image.

(Summary of the Invention) The present invention relates to a motion vector detection circuit for image signals, and includes an operation for applying horizontal and vertical offset values to pixels used for detecting frame differences in a motion vector detection circuit using a pattern matching method. It is added.

This allows the range of detectable motion vectors to be easily expanded without increasing the scale of the hardware.

(Prior Art) Conventionally, a motion vector detection circuit using a pattern matching method has a configuration shown in FIG.

In the pattern matching method, as shown in FIG. The absolute value of the frame difference with that pixel of the current frame is determined by the subtracter 3, the absolute value of the frame difference is added by the number of representative points in the frame difference adding section 4, and then the added value is obtained. This is a motion vector detection method that utilizes image correlation, in which the minimum value detection unit 5 determines a sample vector with the minimum value, and uses the determined sample vector as the motion vector of the image.

The purpose of setting representative points using the method described above is to reduce the number of calculations and reduce the hardware scale. Therefore, the detectable range of motion vectors depends on the type of sample vector, and The variety is directly related to the scale of the hardware, and its increase immediately led to an exponential increase in scale.

(Problems to be Solved by the Invention) In the conventional motion vector detection method using the pattern matching method, the motion vector detection range is limited by the type of sample vector. Increasing the number of sample vectors increases the number of calculations, which has the disadvantage of dramatically increasing the scale of the hardware.

Therefore, an object of the present invention is to provide horizontal and vertical offset values to the input image for a certain number of sample vectors, thereby expanding the detectable range of motion vectors without significantly increasing the scale of the hardware. It is an object of the present invention to provide a motion vector detection circuit.

(Means for Solving the Problems) That is, the motion vector detection circuit of the present invention includes a frame memory, a representative point setting unit connected to the output of the frame memory for subsampling the image, and an absolute frame difference between the current frame and the previous frame image. a frame difference addition unit that adds values by the number of representative points set by the representative point setting unit according to the sample vector of the motion vector; a frame difference addition unit that detects a minimum value of the frame difference addition values obtained by the frame difference addition unit; A minimum value detection section that outputs horizontal and vertical motion vectors, and a horizontal offset control section that controls an offset value of the horizontal motion vector and an offset value of the vertical motion vector from the output of the minimum value detection section, respectively. and a vertical offset control section.

(Examples) The present invention will be described in detail below by way of examples with reference to the accompanying drawings.

FIG. 1 shows a block diagram of a motion vector detection circuit according to an embodiment of the present invention. The frame memory 1, the frame difference adder 4, the minimum value detector 5, etc. are the same as the conventional circuit.The embodiment of the present invention connects these circuits and the frame memory 2, and sets a representative point under offset control. Part 2
and a horizontal offset control unit 11 that calculates horizontal and vertical offset values from the horizontal and vertical motion vector values of the minimum value detection unit and controls the representative point setting unit 2, switch 6, and switch 9, and vertical offset control. 12 and an adder 8 for adding values from offset units 7 and 10.

Let the range of the sample vector be horizontal and vertical.

Further, the outputs of the horizontal offset control section 11 and the vertical offset control section 12 are α and β, and the following is assumed.

The horizontal and vertical offset values of the n+1 frame are δV
, e*1. If δV, nu, then δ■, n+1
= δV, n+α・ΔV, (4) δ■, f
i+飄=δV, n+β・,! IVy (5)
becomes. The offset value of the position of the pixel to be subsampled in the representative point setting section is δx″+′ in equations (4) and (5).
.

δV, ″ (see Figure 3), while δV , n+
1°δV and +++1, respectively, as shown in FIG.
and switches 6 and 9, the initial state is α = β = O (7) Assuming that switch 6.9 is connected to contact B, α
, β is switched by the switch 6.9.

Therefore, the horizontal and vertical motion vectors V, , V, of the n-th frame to be obtained are as follows, and the detection range has increased by the value of δVx'+δvy''.The horizontal and vertical offset control units 11.12 This can be easily realized using the following methods, and the scale of the hardware will not be large.

In this embodiment, the image is offset using representative points, but it may also be applied to the image of the current frame. or,
Although the offset values δ■x'' and δ■y'' are limited by equation (6), it is of course possible to widen them, and in this case, the detection range becomes larger.

(Effects of the Invention) As explained above, if the motion vector detection circuit of the present invention is used, the possible range of sample vectors in the pattern matching method, which was conventionally limited by the scale of hardware implementation, can be improved. By allowing offset vectors to be set in the horizontal and vertical directions, the detectable range of motion vectors can be dramatically expanded without significantly increasing the scale of hardware.

[Brief explanation of the drawing]

Fig. 1 shows a configuration diagram of an embodiment of the present invention, Fig. 2 shows a conceptual diagram for explaining a pattern matching method using representative points, and Fig. 3 shows a state of representative point offset. Figure 4 shows a configuration diagram of a conventional motion vector detection circuit. 1... Frame memory 2, 13... Representative point setting section 3... Subtractor 4... Frame difference addition section 5... Minimum value detection section 6, 9... Switching device 7;
10...Offset coefficient unit 8...Adder 11...Horizontal offset control section 12...Vertical offset control section

Claims (1)

[Claims] 1. A representative point setting unit that includes a frame memory and connects to the output of the representative point setting unit that subsamples the image, and determines the absolute value of the frame difference between the current frame and the previous frame image according to the sample vector of the motion vector a frame difference addition unit that adds the number of representative points set by the representative point setting unit; a minimum value that detects the minimum value of the frame difference addition values obtained by the frame difference addition unit and outputs horizontal and vertical motion vectors; The present invention includes a detection unit and a horizontal offset control unit and a vertical offset control unit that respectively control an offset value of a horizontal motion vector and an offset value of a vertical motion vector from the output of the minimum value detection unit. Features a motion vector detection circuit.