JPH04324774A - Picture storage device - Google Patents

Abstract

PURPOSE:To obtain non-consecutive picture from a moving picture fetched in a memory. CONSTITUTION:A write address counter 16 generates a write address which skips as to a write inhibit position designated by a memory management circuit 24, and designates cyclically a storage position of a multi-port random access memory 14 as to other addresses.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image storage device.

0002

2. Description of the Related Art A memory or its address control that stores data cyclically in a storage area by connecting the end address of the storage area to the start address of the storage area is well known as a so-called ring memory. Image storage devices that store image signals in ring memories are already known.

0003

[Problem to be solved by the invention] In the ring memory,
Due to address control, previously stored information cannot be protected from writing of subsequent information. for example,
When storing moving images, the previously stored image disappears with the next image, making it impossible to obtain temporally discontinuous images.

An object of the present invention is to provide an image storage device that solves these problems.

[0005]

[Means for Solving the Problems] An image storage device according to the present invention includes an image memory capable of storing a predetermined number of images, a write address generation means for generating a write address for the image memory, and the write address generation means. The image forming apparatus is characterized by comprising a control means for controlling a specified area of the image memory and prohibiting generation of a write address in a specified area of the image memory.

[0006]

[Operation] With the above means, it is possible to save the image previously stored in the image memory while storing the subsequent image in another storage area. This makes it possible to extract discontinuous images from a moving image.

[0007]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of an embodiment of the present invention applied to output processing of a video camera. 10 is a video camera; 12 is an A/D converter that digitizes the video signal output from the video camera 10; 14;
is a multiport random access memory that stores the digital video signal output from the A/D converter 12. In this embodiment, the memory 14 has a storage capacity capable of storing several seconds to several tens of seconds of video signals.

Reference numeral 16 indicates a memory 14 in response to a synchronization signal superimposed on a video signal output from the video camera 10.
A write address counter 18 generates a write address of the memory 14, a read address counter 20 generates a read address of the memory 14, and a D converts the video data read from the memory 14 into an analog signal.
/A converter, 22 is an output terminal.

Further, 24 is a write address counter 1 according to the registered write prohibited area of the memory 14.
6 and a read address counter 18. The user sets and registers in the memory management circuit 24 a write-protected area of the memory 14, that is, an arbitrary number of images to be saved.

Next, the operation will be explained. Video camera 1
The video signal output from 0 is digitized by the A/D converter 12 and written to the address indicated by the write address counter 16. The address of write address counter 16 is incremented by a synchronization signal superimposed on the video signal. After the write address counter 16 reaches the end address of the memory 14, it becomes the start address of the memory 14. This causes the memory 14 to operate as a ring memory. FIG. 2 schematically shows write addresses of the memory 14. The writing position is represented as a vector W rotating at an angular velocity ω.

[0012] When there is a scene to be saved during shooting and this scene is written to the memory 14, the memory management circuit 2 immediately
Instruct 4 to prohibit writing. At this time, any size can be registered at any storage location in the memory 14.

[0013] After registration is completed, photographing is resumed. The write address counter 16 skips write addresses for storage areas registered in the memory management circuit 24. For example, if writing is prohibited in the range a-b shown in FIG. 3, when the write vector W reaches point a, it skips the area between a-b and then writes data at point b. This saves the video data stored in the area between a and b.

Next, another embodiment applied to processing of an n-times speed video signal will be described. FIG. 4 shows its configuration block diagram. The same components as in FIG. 1 are given the same reference numerals. 3
0 is a video camera capable of photographing at a field frequency n times that of a standard television signal, and its output video signal is processed by an A/D converter 12, a write address counter 16, and a memory management circuit 24 as shown in the figure. 1, it is written to the memory 14. The slow playback control circuit 32 controls the read address counter 34 to
Data is read from the memory 14 at an arbitrary speed, and the read data is transferred to the D/A conversion and format conversion circuit 36.
to a standard television signal. This results in
An arbitrary slow video signal is output from output terminal 38.

[0015]

As can be easily understood from the above description, according to the present invention, discontinuous images can be extracted from moving images.

[Brief explanation of the drawing]

FIG. 1 is a configuration block diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of the operation of the memory 14.

FIG. 3 is an explanatory diagram of the operation when a write-protected area is provided in the memory 14.

FIG. 4 is a configuration block diagram of another embodiment.

[Explanation of symbols]

10: Video camera 12: A/D converter 14
:Multi-port random access memory 16
:Write address counter 18:Read address counter 20:D/A converter 22:Output terminal 30:Video camera 32:Slow playback control circuit 34:Read address counter 36:D
/A and system conversion circuit 38: Output terminal

Claims (1)

[Claims] 1. An image memory capable of storing a predetermined number of images, a write address generating means for generating a write address for the image memory, and a write address generating means for controlling the write address generating means to generate a write address for a specified area of the image memory. 1. An image storage device comprising: control means for prohibiting the occurrence of .