JPH0391378A - Video camera equipment - Google Patents

Abstract

PURPOSE:To attain a more effective correction function for camera blur by eliminating a high frequency component and detecting a moving vector based on an edge signal set optimizingly in response to an object to obtain moving vector information without misdetection. CONSTITUTION:An object image formed on a photodetecting face of an image pickup element 102 through a lens 101 is subject to photoelectric conversion and extracted as a camera output via a signal processing circuit 103. On the other hand, an edge signal (a) resulting from detection of only a contour of a video signal is outputted from an edge detection circuit 104 and inputted to an LPF 105. The LPF 105 unshapens the signal (a) to convert it into an edge signal (b) with a high frequency component eliminated therefrom. The signal (b) outputted from the LPF 105 is inputted to a peak detection circuit 106 and to a binarizing circuit 107 whose threshold voltage (d) is set thereby. The circuit 107 outputs a digital edge signal (c) by using the voltage (d) as a reference signal. Thus, the video signal is converted into the digital edge signal, the signal component from an object 404 is eliminated and only a signal from an object 403 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an imaging device using a solid-state imaging device, and particularly to a method for detecting motion information necessary for correcting camera shake.

[Conventional technology]

In recent years, as home video cameras have become smaller and lighter, and lenses have become higher magnification, it has become possible to suppress image blur caused by camera shake and vibration without using a tripod or other fixed device.
There is an increasing demand for video cameras that can obtain stable images.

As a conventional means for detecting motion information necessary for correcting image shake, there is known a method described in, for example, Japanese Unexamined Patent Publication No. 82066/1983.

This has an image compression means that compresses a two-dimensional image signal into a one-dimensional image signal, and an image memory that stores the one-dimensional image signal, and the image signal output from the image compression means and the image memory. The objective is to detect the movement of the subject as a motion vector from the correlation between the image signal output from the camera and the image signal output from the camera. The above-mentioned conventional example will be explained below with reference to the drawings. Fig. 2 shows the relationship between the above-mentioned two-dimensional image signal and the signal output obtained by compressing the image signal into one-dimensional form.
Here, as shown in 201, there is a triangular object 200 with high brightness in a part of the screen. When this image signal is used with the image compression means, the output signal from the image compression means is as shown in FIG.
It will be like 2. After storing this output signal in the image memory, when the subject 200 moves upward, CB
), the output signal from the image compression means is 204 for the image signal 205. This output signal 2
04 and the output signal 202 of the image memory, the vertical movement of the object triangle 200 can be detected.

[Problem to be solved by the invention]

In the conventional technique described above, when detecting the movement of a subject having a diagonal component such as the subject 600 shown in FIG. 5, the following malfunction occurs.

As shown in (-) in the same figure, a part of the subject 300 is the image signal 501.
and an output signal 302 is obtained by the image compression means. After that, as shown in Figure CB), the subject 300
When it moves in the horizontal direction and reaches the position 500', the output signal of the image compression means is 304. This is the same output signal of the image compression means when the subject 300 moves vertically downward 500'. Therefore, when the correlation between the output signals 302 and 304 is determined, an error occurs in which an object that is actually moving in the horizontal direction is detected as an object that has moved in the vertical direction.

The purpose of the present invention is to detect the edges of an image signal and then pass it through a low-pass filter (LPF) to remove oblique components and perform motion detection without false detection. It is an object of the present invention to provide a video camera having an easy-to-use camera shake correction function, which can significantly simplify the circuit scale.

[Means to solve the problem]

In order to achieve the above object, the imaging device of the present invention is capable of detecting horizontal or vertical movement by detecting edges representing the outline of a subject, removing high frequency components of the edge signals, and performing calculations. That is.

Furthermore, when the edge signal is binarized and converted into a digital signal, a peak detection circuit is used to optimize the conversion depending on the subject, and the edge signal is detected to optimize the threshold value. This enables the above-mentioned motion detection without malfunction.

[Effect]

According to the present invention, it is possible to perform motion detection for a single image without any malfunction without requiring complicated calculation means as in the past, and it is possible to correct camera shake based on the detected motion vector information. can.

〔Example〕

A first embodiment of the present invention will be described below. First, in this embodiment, a case will be described in which the movement of a subject in the vertical direction is detected. FIG. 1 is a block diagram of a video camera device according to an embodiment of the present invention.

101 is a lens, 102 is a solid-state image sensor (hereinafter referred to as an image sensor), 103 is a signal processing circuit, 104 is an edge detection circuit, 105 is an Ω-pass filter (LPF), 107
106 is a peak detection circuit that detects the edge signal and determines a threshold for binarizing it; 106 and 107 are memories; 10B is a view of the memories 106 and 107; A memory control circuit 109 controls write and read pulses;
112 is a camera shake correction circuit. FIG. 4 schematically shows the state of the light receiving surface 403 of the image sensor 102, and in particular, FIG.
, 4) are expressed in pixel units. lens 101
The object imaged on the light receiving surface of the image sensor 102 is photoelectrically converted and taken out as a camera output via the signal processing circuit 105. On the other hand, the edge detection circuit 104 outputs an edge signal α in which only the outline of the video signal is detected, and LpF
105. L p F 105 is the edge signal α
The signal is rounded and converted into an edge signal with high frequency components removed. The edge signal output from the LP1105 is input to the peak detection circuit M1015 to set the threshold voltage d.
It is input to the value conversion circuit 107. The edge signal S is inputted to the 2f straightening circuit 107, and a digital edge signal C is outputted based on the threshold voltage d.

Therefore, the video signal shown in FIG. 4 CB) is converted to the digital edge signal shown in C1 of the same figure, and the subject 404 is deleted and only the subject 403 is detected as shown in CC) of the same figure. When this moves vertically downward as shown by the arrow in the figure, the digital edge signal becomes C2 in the figure, and by correlating C1 and C2, it is possible to detect the object 405.
vertical movement can be detected.

Memories 108 and 109 store the digital edge signal C mentioned above. Memory 108 is 1 field previous memory 1
09 stores the digital edge signal of the current field,
The output signals e and f are respectively input to the arithmetic circuit 111 to obtain motion vector information l representing motion information, which is input to the camera shake correction circuit, making it possible to correct screen shake due to camera shake. . The memory control circuit 110 controls the write timing and read timing pulses h and i of the memos 9108 and 109, thereby storing the digital edge signal C in the memories 108 and 109 for each field.

FIG. 5 shows a second embodiment. This embodiment is a video camera device that detects the movement of a subject in the horizontal direction.

By inputting the digital edge signal l output from the binarization circuit 107 to the digital LPF so1, the high frequency component of each edge in the horizontal direction is removed, and the same effect as in the first embodiment can be obtained.

Similar to FIG. N4, FIG. 7 schematically represents the state of the light-receiving surface 402 of the image sensor 102 in pixel units.

The existence of an edge is detected only when several (five in the figure) or more edges in the horizontal direction are consecutively present in the vertical direction, and the edge is output as a digital edge signal as shown in 702 in the figure.

Another embodiment of the second embodiment is shown in FIG. 6CB). In this case, the digital LpF 501 shown in FIG. CA) is replaced with an edge determination circuit 601 and a memory 602, and the same effect as the second embodiment shown in FIG. 5 can be obtained.

In addition, by setting the number of consecutive edges for determining the above digital edge signal by the edge determination circuit 601 (for example, if the number of consecutive edges is 4)
It is possible to change the number of edges depending on the subject (regarded as an edge signal when the number of edges is 1), thereby making it possible to perform motion detection without false detection.

〔Effect of the invention〕

According to the present invention, in a video camera device having a conventional camera shake correction function, it is possible to remove high frequency components and detect a motion vector based on an edge signal that is optimally set according to the subject. This results in
It is possible to obtain motion vector information without erroneous detection, and to have a more effective camera shake correction function without erroneous operation.

[Brief explanation of drawings]

Figure N1 is a block diagram of a camera system showing an embodiment of the present invention, Figures 2 and 3 are diagrams showing video output to explain conventional motion vector detection, and Figure 4 is a diagram showing video signals and edge data. Diagrams showing the relationship with signals: Fig. 5 is a block diagram of the camera system showing the second embodiment, Fig. 6 is a block diagram showing the fifth embodiment, and Fig. 7 shows the relationship between video signals and horizontal edges. FIG. 3 is a diagram showing the relationship with signals. 102... Solid-state image sensor 105... Signal processing circuit 104... Edge detection circuit 105... LpF1
06...Peak detection circuit 107...Binarization circuit 1
013.109...Memory 111...Arithmetic circuit 112...Camera shake correction circuit 501...Digital LpF 601...Edge judgment circuit 602...Memory

Claims (1)

[Claims] A video camera comprising a solid-state imaging device in which photodiodes are arranged in one or two dimensions, and a signal processing circuit that converts a video signal output from the device into a normal camera output. an edge detection means for outputting an edge representing the outline of a subject as a first edge signal from the camera output from the circuit; and a low-pass filter for generating a second edge signal by removing high frequency components of the first edge signal. , storage means for storing the second edge signal, and motion vector detection means for determining the correlation between the output signal from the storage means and the second edge signal and detecting the movement of the subject. A video camera device comprising: 2. The video camera according to claim 1, wherein the edge detection means includes means for optimally controlling the number of edges by changing a threshold value for determining an edge depending on the subject to be imaged. Device.