JPH02304598A - Image reader - Google Patents

Abstract

PURPOSE:To momently obtain a picture of desired magnification without trouble some operation like fine adjustment of a zoom lens by changing the sampling period of a taken-in input picture signal to expand/reduce the picture. CONSTITUTION:The picture signal inputted from a camera 2 is subjected to A/D conversion by a sampling circuit 3 and has each picture element written in a frame memory 5 by a memory write controller 4. For example, when a user operates an expansion indicator 9 to set magnifications to 2 and designates expansion of a part 'a', a command to extend the sampling period twice is sent from an expansion control part 8 to the sampling circuit 3, and the indication to write only the picture corresponding to the part 'a' in the frame memory 5 is generated for the memory write controller 4, and 'a' is expanded and displayed on a screen overall. Thus, the expanded picture is easily displayed without the fine adjustment for optical expansion due to zoom lens operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image reading device, and particularly to an image reading device that can enlarge/reduce images of television video information, printed matter, etc. and display them on a CRT.

[Prior Art] Image reading devices that can enlarge and reduce the display of flat materials such as printed materials and slides, as well as visual information and audio from VTRs and still video players, have been developed, and are used for presentation of materials at planning meetings and audiovisual education in schools. It is widely used as a method.

FIG. 3 shows a block diagram of the configuration of this type of conventional device.

A camera (2) is fixed to the camera stand (1), and image signals captured by the camera (1) are sent to a sampling circuit (3). Furthermore, camera (2) can transmit clear images of printed materials such as manuscripts, beers, liquids in flasks, etc., and can also be used as a regular video camera by removing the adapter lens. It is configured.

The sampling circuit (3) samples the image signal from the camera (2) at a certain period of T3 seconds, and sends the image signal to the A/
After D conversion, it is output to the frame memory (5).

The digital image signals once stored in the frame memory (5) are then sequentially read out by the output circuit (6) and displayed on the CRT (7).

Then, when it is necessary to enlarge and read the imaging target, such as a document on the camera stand (1), the camera (2)
A method was adopted in which the image was optically enlarged by operating a zoom lens (10) attached to the tip of the lens.

[Problems to be Solved by the Invention] However, in the method of enlarging an input image in the conventional device described above, in addition to enlarging the zoom lens (10) itself, delicate focusing etc. must be performed with great care each time. However, there was a problem in that complicated and troublesome work was unavoidable.

The present invention was made in view of the above-mentioned conventional problems, and its purpose is to easily enlarge input image data without requiring analog fine adjustments such as zoom lens operation and focusing each time. An object of the present invention is to provide an image reading device that obtains images.

[Means for Solving the Problems] In order to achieve the above object, the present invention changes the sampling period of input image data captured according to setting instructions from the user, changes the number of captured pixels, and performs enlargement control. The present invention is characterized in that a partial enlarged display is performed by writing only a portion designated by a frame memory into a frame memory and reading this at a predetermined period.

[Operation] According to the device of the present invention configured as described above, the sampling circuit changes the sampling period in response to a command from the enlargement indicator, and the memory write controller frames only the image data of the instructed part. write to memory.

As a result, the input image data is digitally enlarged by changing (increasing) the sampling period, and an enlarged image can be easily displayed without requiring fine adjustments for optical enlargement by operating a zoom lens. can.

[Example] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

In the figure, the same reference numerals are given to the same components as those of the conventional device shown in FIG. 3, and the explanation thereof will be omitted. FIG. 1 shows a block diagram of the configuration of the apparatus of the present invention. As is clear from the figure, in the present invention, a memory write controller (4) is connected between the sampling circuit (3) and the frame memory (5).

The sampling circuit (3), memory write controller (4), and frame memory (5) are placed under the control of an enlargement control section (8), and the enlargement control section (8) is controlled by an enlargement section indicator (
9) performs a predetermined control action through the user's commands sent from the controller.

The operation of the device of the present invention will be explained below.

An image signal manually input from the camera (2) is A/D converted by a sampling circuit (3), and is written to a frame memory (5) by a memory write controller (4) pixel by pixel.

Here, FIG. 3 shows a case where the manual sampling period (number of input pixels) and the output dot period (number of output pixels) are the same, that is, the case where the magnification is 1. The input manuscript size is 1
Use 0c+aX 10cIfl and convert it to 500
Sampling is performed as X500 dots. This will then be displayed on a CRT consisting of the same <500x500 dots.

At this time, the user operates the magnification indicator (9) to increase the magnification by 2.
Suppose that the image is set to double and the part marked "A" in the same figure is enlarged. As a result, the enlargement control unit (8) sends a command to the sampling circuit (3) to double the sampling period, and at the same time, the memory write controller (4) outputs "A".
An instruction is generated to write only the image corresponding to the position into the frame memory (5).

A diagram enlarged in this way is shown in FIG. By doubling the sampling period, the input pixels are 1000x10
00 dots, of which 500×500 dots are cut out and written into the frame memory (5). In Figure 4, if we cut out the position of "A", it would be displayed on a 500x500 dot monitor,
“A” is enlarged to fill the entire screen.

In the above embodiment, the number of pixels is 500 x 500 dots, but the system of the present invention is not limited to this, and can be applied to any number of pixels of NXM dots, and can be reduced not only by enlarging but also by lengthening the sampling period. can also be done.

Further, in the above embodiment, a camera is used as a means for capturing an image, but instead of this, a manual device such as a scanner may be used.

[Effects of the Invention] As explained above, according to the present invention, the captured input image signal is enlarged/reduced by changing the sampling period, so it can be enlarged/reduced instantly without the need for troublesome operations such as fine adjustment of the zoom lens. It becomes possible to obtain an image with a desired magnification.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the structure of an image reading device according to an embodiment of the present invention, FIG. 2 is an input/display diagram for the same magnification, FIG. 3 is a manual/display diagram for enlargement by the method of the present invention, and FIG. The figure is a block diagram of a conventional image reading device. In the figure, (1) is the camera stand, (2) is the camera, (3
) is a sampling circuit, (4) is a memory write controller,
(5) is a frame memory, (6) is an output circuit, (7) is a CRT, (8) is an enlargement control section, and (9) is an enlargement section indicator. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. - 翳OcM Input table Input/display of calculation f combination 1 Fig. 2 Input of tree climbing e month l Kojiru I Hirodai # input/gishi Fig. 3

Claims (1)

[Scope of Claims] A sampling circuit that samples an image signal captured by a camera at predetermined intervals and A/D converts it, and a frame memory that temporarily stores and holds the digital image signal output from the sampling circuit. , an output circuit that reads image data in the frame memory and displays it on a CRT; a memory write controller that controls writing of the data image signal from the sampling circuit to the frame memory; an enlarging unit indicator that allows a user to set and instruct a portion of an input image captured by the camera to be enlarged; and an enlargement control unit that instructs a write controller to write image data to be enlarged into the frame memory, and is capable of digitally enlarging/reducing the displayed image by changing the sampling period of the input image signal. An image reading device characterized in that it is configured as follows.