JP2001036808A - Video camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve picture quality by providing a function for generating an arithmetic objective area signal showing an area requesting data required for picture control such as iris control, white balance so as to designate an optional arithmetic objective area from a picture. SOLUTION: A control means 7 controls an AD conversion means 3, a video signal processing means 4, an image format conversion means 5 and a driving means 6. The control of an iris and that of white balance are also processed here. Integration processing of luminance and a color difference necessary for this processing is executed in the means 4. Then an arithmetic objective area signal showing an area requesting data required for picture control such as iris control, white balance so as to designate an optional arithmetic objective area from a picture. Consequently, since restriction can be given so as to use only data within the same area as a segmented picture for picture control, picture quality can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera for performing digital output.

[0002]

2. Description of the Related Art In recent years, electronic pan-tilt functions have become common in video cameras, and a part of an image has been cut out and displayed.

Normally, the brightness of the screen of an image, that is, the signal level is increased to increase the brightness when the subject is dark, and the color is controlled so that the color appears correctly. These operations are performed on a screen basis, and in order to cope with a case where a bright part and a dark part coexist, various measures such as control with an emphasis on the center of the screen have been devised.

This is sufficient for projecting the entire screen, but is not sufficient for cutting out. For example, the image quality becomes hard to see when the cut-out area is dark.

To cope with these problems, Japanese Patent Application Laid-Open No. Hei 5-244
No. 489 proposes to control an image using data of a zoom area.

As disclosed in Japanese Patent Application Laid-Open No. 5-244489, generally, when an image is cut out, the CC
A video signal obtained by processing the signal output from D is temporarily stored in an image memory. Thereafter, data of a necessary area is retrieved from the image memory and displayed. Then, this signal is used for calculation to perform image control.

[0007]

However, in the method disclosed in Japanese Patent Application Laid-Open No. 5-244489, an image is stored in a memory for clipping, and control data is required for reading the image. In order to achieve this, it is necessary to have a memory capable of storing data for one screen, and it cannot be applied to an apparatus that does not use a memory.

Japanese Patent Application Laid-Open No. 8-237607 proposes a method of changing the size of an image without using a memory. This method can cut out the image as well as change the size of the image, but it is difficult to improve the image quality.

[0009]

SUMMARY OF THE INVENTION A video camera according to the present invention solves the above-mentioned problems, and generates a calculation target area signal indicating an area for obtaining data required for image control such as iris control and white balance. In addition, there is provided a means for performing data processing only during a period in which this signal is active, thereby performing control using data of only the cut-out area.

Further, by providing means for designating a calculation target area in addition to the cutout area designating means, the calculation target area and the cutout area can be specified separately.

When the pan / tilt is executed, if the scroll is performed in the operation, the setting of the cutout position is incomplete, and when a new field starts, the image is disturbed. Until all settings are made, control is performed so that new settings are not made effective.

Further, means for obtaining a division size based on the set size data of the calculation target area is provided so that weighting such as center emphasis can be performed.

Further, there is provided a means for deriving the calculation area from the minimum unit, instead of calculating the division size from the size of the calculation target area.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a video camera according to the present invention will be described with reference to FIGS. <First Embodiment> A video camera according to a first embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 is a block diagram showing an embodiment of a video camera according to the present invention. In FIG. 1, an output signal from an image pickup means 1 for converting a light image captured by a lens into an electric signal is sampled and held. The preprocessing means 2 performs automatic gain correction and the like. The AD conversion means 3 converts the output signal from the preprocessing means 2 into digital data in pixel units and outputs the digital data to the video signal processing means 4, where it generates and outputs a luminance signal and a color difference signal.

The image format conversion means 5 is a block for converting to an arbitrary image size. Here, it is assumed that the image format conversion means 5 is used to cut out an arbitrary area from each of the horizontal and vertical directions.

The drive means 6 generates a drive timing pulse for controlling the image pickup means 1. The control means 7 controls the AD conversion means 3, the video signal processing means 4, the image format conversion means 5, and the driving means 6. The iris control and the white balance control are also processed here. The integration processing of the luminance and the color difference necessary for this processing is performed in the video signal processing means 4.

Normally, the result of integrating the luminance signal is used for controlling the iris, and the result of integrating the color difference signal is used for controlling the white balance. For this reason, usually, the addition processing for this is performed during the period in which the data of the entire screen is valid.

However, in the present invention, in order to further restrict the area of data used for the addition processing, a signal having a waveform shown in FIG. 2 in the horizontal direction is generated based on the circuit shown in FIG. In the vertical direction, a signal having the waveform shown in FIG. 4 is generated based on the circuit shown in FIG.

FIG. 2 shows four effective lines in the vertical direction.
FIG. 4 is a timing diagram when lines 5, 6, and 7 are used. As a circuit, as shown in FIG.
1; match detections 32 and 33;

If the start line position is set to 3 and the end line position is set to 7, after VD is released, the counter 31 is incremented by 1 when one effective horizontal line ends. The detection 32 becomes active, and the FF 34 is set. Subsequently, when the count is 7, that is, after the completion of 7 lines, the coincidence detection 33 on the reset side is performed.
Becomes active, and the FF 34 is reset.

In this way, an active signal is generated only during the period of 4 to 7 lines. The horizontal has the same configuration, but the operation is to count dots only during the horizontal valid period.

FIG. 4 is a timing chart in the case where the effective dot positions are 3, 4, and 5. As shown in FIG. 5, the circuit performs the counting operation by clearing the dot clock and using the horizontal effective period as a clock. , A match detection 52, 53, and an FF 54.

Since the dot counter 51 counts the dot clock after the horizontal effective period becomes "H", it counts up by +1 at the end of one pixel.

The start dot position is 2 and the end dot position is 5
Then, the coincidence detection 52 becomes active at the end of two pixels, and the horizontal data operation period is set to “H”. continue,
When the count reaches 5, the reset side coincidence detection 53 of the FF is performed.
Becomes active, and resets the horizontal data operation period.

As a result, dots 3, 4, and 5 are used for the calculation. By performing the AND processing on the horizontal and vertical operation periods, it is possible to generate an operation period signal that becomes 'h' only during the period of 3, 4, and 5 dots of the 4, 5, 6, and 7 lines. In this manner, only a partial area on the screen can be used for calculation.

FIG. 6 is an explanatory diagram of the calculation valid period signal generating unit. Normally, all the valid data in one screen, for example, data during the horizontal valid period of 'h' is processed. By performing an AND process on the signal and the AND 61, the original purpose can be achieved.

Although a very small area is used in this description, it is needless to say that the size is originally QCIF, CIF or the like. <Second Embodiment> A video camera according to a second embodiment of the present invention will be described in detail with reference to FIG.

Although it is possible to make the signal of the calculation period generated as described above the same as the effective period used for display,
Needless to say, it is actually necessary to insert the delay in consideration of the signal delay in each block. In such a case, since the area used for the calculation and the displayed area are the same, the image quality, which is the initial purpose, is improved, and the circuit is economical.

However, the control needs to be changed in accordance with the size of the region cut out for display, which is complicated. For example, the integrated value of the luminance signal is used for controlling the iris. Even if the brightness is the same, if the calculation area is small, the calculation result is naturally small. At this time, since it must not be determined that the screen is dark, the determination in the control requires correction according to the area.

If it is important to inherit the past assets such as microcomputer software related to this type of control as they are, it is more convenient to prohibit this function.
Therefore, in order to provide hardware that can arbitrarily switch between the two, it is more versatile to have set values separately.

When the signal indicating the calculation area is also used for display, the screen is cut out and the screen position is continuously changed, so that the horizontal / vertical start and end positions of the screen are not set properly. When a new field is started, the screen is disturbed. The reason for this is that the start / end position setting indicated by the signal is a pair, and if this relationship is broken, the size of the image will be out of order. Therefore, these must be validated when they are all completed.

FIG. 7 is a circuit diagram for setting the setting timing of the setting data. In this method, a flag is provided for each data, and the data is validated when all the flags are set. However, here, a method that is effective when the vertical end line position is set will be described. In other words, the setting is executed on the promise that the other three parties are set first.

That is, as the operation, when the data of the above three parties are respectively set, they are stored in the FFs 71 to 73. Subsequently, when the last end line position is set, the clock becomes the clock of the FFs 74 to 77. At the same time as the end line set value given from the data is taken into the FF 77, the data of the FFs 71 to 77, 73
Are shifted to the FFs 74 to 76, and all related data are set at the same time. <Third Embodiment> A video camera according to a third embodiment of the present invention will be described in detail with reference to FIGS.

In the control of the iris and the like, a method such as center-weighted photometry is generally used, and it is general that the screen is divided into several regions instead of the entire screen, and each is weighted.

In the case of the 4 × 4 block shown in FIG. 8, the number of horizontal pixels and the number of vertical lines are generally divided into four, and this value may be directly specified. This boundary is determined by comparing the difference between the position and the start position with a value obtained by quartering.

FIG. 9 is a block diagram of the horizontal area division for this purpose, and FIG. 10 is a block diagram of the vertical area division.

First, regarding the operation in the horizontal direction, when the horizontal effective period is inactive, the dot number counter 94 and the area counter 95 are reset. Then, in the horizontal data calculation period, the dot number counter 94 starts counting according to the dot clock.

The difference between the end dot position and the start dot position is obtained by a subtracter 91, and 1/4 of the number of horizontal dots used for the calculation is output by a 1/4 circuit 92.
If the value matches 4, the output of the match detection 93 becomes active, and the area counter 95 is incremented by 1 and the dot number counter 94 is cleared. In this way, the horizontal area signal counts up to 0, 1, 2, and 3.

Similarly, in the vertical direction, the line number counter 104 and the area counter 105 are reset by VD. Then, the line number counter 104 counts a signal in a horizontal effective period when a vertical data operation period comes.

The difference between the end line position and the start line position is obtained by the subtracter 101, and 1/4 of the number of lines in the vertical direction used for the calculation is output by the 1/4 circuit 102. The output of the match detection 103 becomes active, and the area counter 105 is incremented by one and the line number counter 104 is cleared.

In this way, the vertical area signals are 0, 1,
The count advances to 2, 3 and is divided into 16 horizontally / vertically into 4 × 4 areas shown in FIG. 8, and if the multiplication parameter for the luminance signal is changed according to this state, the calculation area Weighting processing can be performed regardless of the size of.

[0043]

Since the video camera of the present invention has the above-described configuration, it is possible to restrict only data in the same area as the cut-out screen for image quality control. Improvements can be achieved.

Further, since the area to be cut out and the area to be used for image quality control can be different, it is easy to divert past assets, and even if the target product is image quality, It is possible to provide a circuit that can cope with the development speed and cost.

Further, it is possible to prevent the image from being disturbed due to the variation in the set timing. Further, even if the calculation area is changed, area division can be performed, and the accuracy of image quality control can be improved.

Further, the division size is automatically derived from the entire region size without setting the size of the division region, so that not only the trouble but also the erroneous setting can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a video camera according to the present invention.

FIG. 2 is a timing chart when effective lines in the vertical direction are 4, 5, 6, and 7 lines.

FIG. 3 is a circuit diagram for extracting a vertical operation area.

FIG. 4 is a timing chart when effective dot positions are 3, 4, and 5;

FIG. 5 is a circuit diagram for extracting a horizontal operation area.

FIG. 6 is an explanatory diagram of a calculation valid period signal generation unit.

FIG. 7 is a circuit diagram for setting timing of setting data.

FIG. 8 is an explanatory diagram of screen division.

FIG. 9 is a block diagram of horizontal area division.

FIG. 10 is a block diagram of vertical area division.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 imaging means 2 preprocessing means 3 A / D conversion means 4 video signal processing means 5 image format conversion means 6 driving means 7 control means 31 counter 32 coincidence detection 34 FF 61 AND 91 subtractor 94 dot number counter 95 area counter 104 line Number counter

Claims (5)

[Claims] 1. An image pickup means for picking up an image of a subject and converting it into an electric signal, a video signal processing means for processing the electric signal and converting it into a digital image signal, and controlling a signal indicating a valid period of the image data. In a video camera having a screen cutout means for cutting out a part of a screen, a calculation target area signal indicating an area for obtaining data necessary for image control such as iris control and white balance is generated, and an arbitrary calculation target area is selected from the screen. A video camera having a function of designating a video camera. 2. The video camera according to claim 1, wherein a region from which the screen is cut out and a calculation target region can be individually designated. 3. The video camera according to claim 1, wherein the setting of the cutout position of the screen is effective at the start of a field following the time when the setting data of the horizontal / vertical start and end positions of the screen are prepared. . 4. The video camera according to claim 1, wherein, within the calculation target region, the region can be divided and data can be weighted regardless of the size of the region. 5. The video camera according to claim 4, wherein the size of the divided area is derived from the designation of the calculation target area.