JPH07162667A - Picture reader - Google Patents

Abstract

PURPOSE:To input only pictures inside the coordinates of two points by specifying an area and to eliminate the other pictures by masking by detecting the boundary of an original and both hands pressing the original and recognizing the inside of the two points to be the boundary as the coordinates. CONSTITUTION:A line sensor 11 is moved on the original 2, the address information of the edge of fingers 100 and 101 and the pictures on respective lines sampled with an appropriate interval is stored in a memory 26 by a CPU 24 and an inmost (maximum or minimum) X coordinate and the Y coordinate of the position are selected from it. Picture information read for the respective lines is converted to digital signals in an A/D converter 22, optical correction is performed in an MTF correction circuit 27 and input to a selector 29 is performed. In the meantime, the CPU 24 refers to the address information of the coordinates (XA, YA) of the left end part of the edge stored in the memory 26 and sends a command for selecting not the picture information sent from the MTF correction circuit 27 but white information outputted from a white level generation circuit 28 to the selector 29 until the line sensor 11 moving in a sub scanning direction arrives at the left end part and after it passes through a right end part XB.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus for reading a document from above and inputting a designated area as an image.

[0002]

2. Description of the Related Art Conventionally, in this type of image reading apparatus,
There is a device that reads only an arbitrary portion of a document as an image and prints it. In such an apparatus, usually, a touch panel or the like is used to designate and print a desired area of a document, or a switch is provided corresponding to the document, and coordinates are detected by this switch to print. Has been adopted.

[0003]

However, in the case where the masking process is performed by using the touch panel, the switch or the like as described above, both the electric system and the mechanical system are complicated and the productivity is deteriorated and the cost of the device is increased. In addition, the operation of the user who handles the device becomes complicated. The present invention has been made to solve the above-mentioned problems, and it is possible to detect a boundary between a document and a hand holding the document based on the read image information, and perform masking and deleting other than a desired region from this to perform a soft process. It is an object of the present invention to provide an image reading apparatus that can be realized only by itself, the electric and mechanical systems are simplified, the productivity is good, the cost is low, and the operation is easy.

[0004]

In order to achieve the above object, the present invention provides an image reading apparatus for reading an original placed on an original table from above from a reading unit for reading an image and the reading unit. Based on the read image information, detection means for detecting the boundary between the original and the hand holding the reading area of the original at a diagonal position, and the detection results by the detection means, the coordinates of the leftmost end of the right hand and the rightmost end of the left hand. And a masking means for masking an outer area of a rectangle whose two coordinates recognized by the recognition means are diagonal lines.

[0005]

In the above structure, by manually pressing the diagonal position of the desired reading area of the document to perform the reading operation, the reading means reads the document placed upward on the document table from above, Based on the read image information, the detection means detects the boundary between the document and the hand holding the reading area of the document at a diagonal position, and the recognition means determines the leftmost coordinate of the right hand and the rightmost coordinate of the left hand. Recognizing and masking means masks the outer area of the rectangle in which the two coordinates recognized by the detecting means are diagonal lines. By such soft processing of the read data, it is possible to obtain an image of only the inner area of the diagonal position.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a document reading apparatus according to this embodiment. The apparatus 1 supports a document table 3 on which a document 2 is placed upward, a reading section 4 provided above the document table 3, and at least a position where the reading area can be always visually recognized. It is composed of a support portion 5. On the document table 3, a document stopper 6 for guiding the placement position of the document 2 and switches 7 for operation.
Further, a signal processing board (not shown) and the like are provided inside the document table 3. For the document stopper 6, it is desirable to use a member having a light reflectance different from that of the document 2 for the correction processing of image information described later.
Black or gray with low reflectance is suitable. In this embodiment, the document stopper 6 is black. Also, the document table 3
An illumination lamp 8 is attached to the reading unit 4 in order to illuminate.

FIG. 2 is a side view of the document reading apparatus 1, a part of which is cut away to show the internal structure of the reading unit 4, and the transmission path of image information is shown by broken lines. Inside the reading unit 4, an image sensor 11, an image forming lens 12 for making image information incident on the image sensor 11, and a reflecting mirror 13 for reflecting an original image on the original table 3 to the image sensor 11 are arranged. There is. A semiconductor photoelectric conversion element such as a CCD line sensor may be used as the image sensor 11, and an area sensor may be used instead of the line sensor.

FIG. 3 shows a signal processing system 21 in the present apparatus 1.
3 is a block diagram showing the configuration of FIG. The signal processing system 21 recognizes and detects an A / D converter 22 that converts the information output from the image sensor 11 into a digital signal, an upper end (hereinafter referred to as an edge) of the image of the document 2 in the image information, and a non-image. The edge detection circuit 23, the CPU 24, the scanner driving unit 25 that drives the reading unit 4, the memory 26, and the MTF (Modulation T) that corrects distortion due to optical characteristics.
transfer function) correction circuit 27, white level generation circuit 28 for generating white level information, C
A selector 29 for selecting and outputting a white level signal and a signal from the MTF correction circuit 28 according to a command from the PU 24,
And an interface for driving the printer 31 (I
/ F) 30 and the like.

The original reading operation of the apparatus 1 having the above-mentioned structure will be described with reference to the flowchart of FIG. The reading target is the page on the left side of the opened original 2, but it may be a sheet original such as a newspaper. Manuscript 2 on manuscript table 3
When the image pickup switch is turned on, the line sensor 11 starts prescanning (# 2). The document edge is detected from the image information read by this prescan (# 3). In photographing by pre-scanning, reading is performed so that the upper end portion 6a of the document stopper 6 shown in FIG. 2 is included.

An example of the image information thus read is shown in FIG. In the normal recognition of the image information 41, the image 42 of the document 2 placed on the spread, the image 43 of the document table 3, and the image 44 of the black document stopper 6 are included, and the document image 42 and the document stopper are included. An edge 45 is generated at the boundary with the image 44. The position of the edge 45 corresponds to which pixel (address) in the line sensor is detected by the edge detection circuit 23 shown in FIG. 10
Reference numerals 0 and 101 denote the images of the left and right fingers of the user holding the document, and both hands hold the diagonal positions of the document portion to be read.

After the detection of the document edge, the area designation image recognition is started, and it is determined whether or not there is a non-image pattern in the image information, that is, whether the finger images 100 and 101 are present in the document portion 42 (# 4). If you have a non-image pattern,
The recognition, that is, the density difference between the background of the document or the area of the character and the area of the finger is detected, and the images 100 and 101 of the finger are recognized (# 8). For this recognition, there is a density difference between the paper background of a document such as a book and the finger, that is, the paper background of the document is usually white, whereas the finger is darker than that and the reading density is The distribution is as illustrated in FIG. 7, and the fingers are recognized by utilizing the density difference between the background area X and the finger areas Y of the document.

Next, the fingers 100 and 10 recognized above
The coordinates of each edge portion are recognized from the edges of 1 and the image (# 9). As shown in FIG. 6, the coordinate recognition is performed by calculating the rightmost coordinate point A of the left finger 100 and the leftmost coordinate point B of the right finger 101 in the left-right x-axis direction, and these coordinate points Coordinates inside the point B are extracted,
Area designated coordinates A (XA, YA), area designated coordinates B
Find (XB, YB). In this coordinate recognition, the center X coordinate and the center Y coordinate of the photographing area are used as references, the edge line coordinates XA of the recognized finger 100 are used as the center X coordinates, and high values are used as area coordinates. Similarly, the edge line coordinate XB of the recognized finger 101 is used as a reference for the center X coordinate, and a low value is set as the area coordinate. Further, the Y coordinate of each edge position is obtained.

In the example of FIG. 6, the area coordinate of the finger 100 is XA = -3, YA = 8, and the area coordinate of the finger 101 is X.
B = 5 and YB = -3. The image area inside the diagonal of the area coordinates of the two points is recognized as an arbitrary image. Actually, the line sensor 11 is moved on the document 2 (sub-scanning), and the address information of the edge in each line sampled at an appropriate interval is stored in the memory 26 by the CPU 24.
Then, the innermost (maximum or minimum) X coordinate and the Y coordinate of the position may be selected from among them.

When the prescan is completed, the main scan is started and the image is taken (# 5). In the main scan, the image information read by the line sensor 11 for each line is A / D
The signal is converted into a digital signal by the converter 22 and is optically corrected by the MTF correction circuit 27, and then input to the selector 29. On the other hand, the CPU 24 detects the left end coordinates (X) of the edge detected and stored in the memory 26 during the prescan.
(A, YA), the image sent from the MTF correction circuit 27 to the selector 29 until the line sensor 11 moving in the sub-scanning direction reaches the left end and after passing the right end XB. A command is sent to select the white information output from the white level generating circuit 28 instead of the information.

When it is detected that the line sensor 11 has reached the left end coordinates (XA, YA), it is determined that the photographing of the reading surface of the original 2 has started, and the CPU 24 causes the selector 29 to output the MTF correction circuit 27. Send a command to select the image information to be sent. While the line sensor 11 is reading from the coordinate XA to the coordinate XB, the coordinate Y on the y coordinate is read.
From A to the area other than the coordinate YB, the CPU 24 sends a command to the selector 29 to select white information. CP like this
In response to a command from U24, the selector 29 selects the image information and the white information, so that the frame erasing process in the image information, that is, the unnecessary image can be removed (#
6). When the main scan is completed, the corrected image information that has undergone the frame erasing process is transferred to the printer 31 through the interface 30.
(# 7), and the reading operation is completed.

As described above, by recognizing both fingers holding the document, the coordinates to be read as an image are detected and calculated,
By determining the optimum coordinates based on the result of this calculation, it is possible to specify an arbitrary image area. As a result, since the reading area can be designated without using a complicated mechanism as in the prior art, it is possible to reduce the cost of the configuration and also to simplify the operation.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and various modifications can be made. For example, when recognizing the finger to specify the image area, the edge of the shadow of the finger due to the illumination light may be detected. Further, regarding the configuration of the apparatus, a basic example is shown in FIG. 1 to FIG. 3, but as long as it satisfies the requirements of the present invention, it may be different depending on the application and environment. Further, in the configuration of the above-described embodiment, the printer is used as the output destination of the read image, but in addition to this, the image data is output to a storage device such as a hard disk or the like having a display device such as a CRT as the output destination. Such a configuration may be used.

[0018]

As described above, according to the present invention, the boundary between the document and both hands holding the document is detected by the software processing from the image information obtained by reading the document, and the inside of the two points serving as the boundary is coordinated. By recognizing as, only the image inside the coordinates of these two points can be designated by the area and input, and the other images can be deleted by masking. Therefore,
Unlike conventional devices, it does not require a complicated electrical or mechanical mechanism such as specifying an image area using keys or using a touch panel, resulting in higher productivity and lower cost. There is an effect that it becomes easy.

[Brief description of drawings]

FIG. 1 is an external view of a document reading apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of the device.

FIG. 3 is a block diagram showing a configuration of a signal processing system in this device.

FIG. 4 is a flowchart showing a document reading operation of this apparatus.

FIG. 5 is a diagram showing an example of read image information.

FIG. 6 is a diagram illustrating a method of coordinate recognition.

FIG. 7 is a diagram showing an example of a read density distribution.

[Explanation of symbols]

 3 Document Platen 4 Reading Unit 11 Image Sensor 24 CPU 28 White Level Generation Circuit 29 Selector

Claims (1)

[Claims] 1. An image reading apparatus for reading an original placed on a platen from above from above, the reading means for reading an image and the reading area of the original based on the image information read by the reading means. Detection means for detecting the boundary between the hand to be pressed at the angular position, recognition means for recognizing the coordinates of the leftmost end of the right hand and the coordinates of the rightmost end of the left hand from the detection result by the detection means, and the recognition means. An image reading apparatus comprising: a masking unit that masks an outer area of a rectangle whose two coordinates are diagonal lines.