JP3372621B2 - Image input device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input device for reading and inputting a printed original image.

[0002]

2. Description of the Related Art Conventionally, it has been practiced to measure a print result printed on paper or the like and evaluate the print state. For this, for example, the printed paper surface is read using a photoelectric conversion element, the read image information is digitally converted and stored in a memory, appropriate image processing is performed, and the image printed on the paper surface is evaluated. ing. At the time of reading by this photoelectric conversion element, a partial area is read and processed by a two-dimensional CCD camera or the like, or a plurality of cameras are moved relative to the paper surface for reading as necessary. Further, even when the line type sensor camera is used, for example, one sensor camera is sequentially scanned to read the paper surface.

[0003]

However, in the above-mentioned conventional example, when reading and processing the A4 paper area with a resolution of 25 μm, for example, a memory capacity of 128 Mbytes is required to store the image data. . Also,
When a two-dimensional camera is used, it is necessary to move the two-dimensional camera by about 300 screens relative to the paper surface and process the partial areas before integration. Similarly, when a line sensor camera is used, if a 5000-bit sensor camera is used, for example, it is necessary to arrange two cameras in series for reading. In this case, for example, 1
If the line sensor is driven by a clock having a frequency of 0 MHz, a large amount of high speed memory is required.

The present invention has been made in view of the above conventional example, and an object of the present invention is to provide an image input device which can flexibly read and store an original image at a low price.

[0005]

In order to achieve the above object, the image input device of the present invention has the following configuration.
That is, by scanning the original image relatively ,
Reads a region using one or more imaging means
An image input device capable of performing the
Provided corresponding to each of the imaging means, the image input to be output to image bus to input image data from said image pickup means
Inputting the image data via a force means and the image bus
A plurality of storage means for and storing, included in the image bus
By switching connection / non-connection of the control signal line
Switching means capable of switching connection between a plurality of storage means
And by switching the switching means,
When reading with the image pickup means,
The amount of image data in the first storage means in the column is less than a predetermined amount.
When it is on the upper side, it is stored in the second storage means, and the plurality of imaging means
When reading with, each of the plurality of imaging means
The image data from this is recorded in a different format corresponding to the imaging means.
It is characterized in that it is stored in a memory .

[0006]

[Operation] With the above configuration, the image is relatively moved on the original image.
Scan one or more scans for a given image area
Can be done using the imager and included in the image bus
By switching connection / non-connection of the control signal line, 1
If you want to read with one imaging method,
The amount of image data in the first storage means in the column is less than a predetermined amount.
When it goes up, it is stored in the second storage means, and the plurality of image pickup means are used.
When reading, read from each of the multiple imaging means.
The image data is stored in different storage means corresponding to the image pickup means.
Remember.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the schematic arrangement of a print evaluation apparatus according to an embodiment of the present invention.

In FIG. 1, the image pickup devices 1 and 2 have a light receiving element (photoelectric conversion element) such as a one-dimensional CCD line sensor, and an inspection sheet (printed on an evaluation object set on a document table 10 is printed. The sheet 9 is imaged in the main scanning direction, converted into an electric signal for each scanning, and output. Lighting unit 14
Illuminates the imaging positions of the imaging devices 1 and 2. The moving mechanism 10 is a mechanism unit for relatively moving the imaging devices 1 and 2 and the inspection sheet 9 in the sub scanning direction 12 orthogonal to the main scanning direction 13. An image on the inspection sheet 9 can be read as a two-dimensional image by the relative movement of the moving mechanism 10 and the imaging devices 1 and 2. In this way, the video signal over the entire area of the inspection sheet 9 to be evaluated, which is obtained by the cooperation of the imaging devices 1 and 2 and the moving mechanism 10, is A / D converted and then input to the image processing unit 4. The image processing unit 4 performs image processing operations such as an image data fetching operation, a histogram operation, and a gravity center operation in accordance with an operation command of the host computer 5.

The moving mechanism control unit 6 controls the moving mechanism 10 in accordance with an operation command from the host computer 5.
The host computer 5 and the image processing unit 4 are connected by a bus 15, and the image data stored in the image memory unit (see FIG. 2) of the image processing unit 4 can be directly read from the host computer 5. The host computer 5 and the moving mechanism control unit 6 are connected by the communication unit 16. The host computer 5 reads out the calculation result in the image processing unit 4 and converts it into a value necessary for evaluation, and the result and the stored image data are monitored 1
Display on 7. Further, an input unit 7 such as a keyboard and a pointing device (PD) 8 such as a mouse are connected to the host computer 5, and an operator can use these to input various parameters necessary for evaluation.

FIG. 2 is a block diagram showing a schematic configuration of the image processing unit 4 of the present embodiment. Portions common to those in FIG. 1 are designated by the same reference numerals, and their description will be omitted.

In FIG. 2, as the image pickup devices 1 and 2, for example, a one-dimensional line sensor camera, a two-dimensional CCD camera or the like is used. Image input units 101 and 102 input image signals from the image pickup devices 1 and 2 and convert them into digital signals, and also output digital image-corrected digital image data. The image input units 101 and 102 also generate and output various timing signals. 103-1
Each of 06 is an image memory unit for storing image data, the details of which will be described later. Reference numeral 109 denotes a CPU bus that transfers information between the host computer 5, the image input units 101 and 102, and the image memory units 103 to 106.
Reference numeral 10 denotes the image input units 101 and 102 and the image memory 103 to.
An image bus for transferring information between 106.

Next, the operation based on the above configuration will be described. <Image Input Unit> FIG. 3 is a block diagram showing the internal configuration of the image input units 101 and 102.

Here, the input video data 126 is
The video data 126, which is output as an analog electric signal from the imaging devices 1 and 2, is converted into a digital signal by the A / D converter 120. The data converted into the digital signal in this way is dark-corrected by the dark correction unit 121, and then input to the shading correction unit 122 and subjected to shading correction. Further, this shading-corrected image data is binarized by the binarization unit 123 as necessary, and is output by the output selection unit 124.
The output is selected and output as image data 128 to the image bus 110. Further, a timing signal generation unit 125 is provided to control the operation of each of the above units, and a control input / output signal 127 input / output from outside and the image bus 1 are provided.
The control signal 129 from 10 or the control signal generated by the timing signal generation unit 125 itself is selected and used as the internal operation signal.

The control signal 129 is output from the image input unit 101 or 102 as a control signal 129 to the external control signal input / output 127 and the image bus 110. By thus enabling the operation by the control signal from the outside, it is possible to input the image data in synchronization with the plurality of image input units 101 and 102.

The various timing signals 130 output from the timing signal generating section 125 are used to control the above-mentioned various sections 120.
~ 124 are controlled. This timing signal 130 is
Timing signal for A / D conversion, clock signal for determining image transfer cycle, synchronization signal required when using one-dimensional line sensor camera or two-dimensional camera, image input start signal from external or host computer 5 (not shown) ) And a transfer area signal for determining an image transfer position (time, time, etc.) from the synchronization signal to the image bus 110.

The various conditions necessary for generating the timing signal 130 are appropriately set in the host computer 5.
From the timing signal generator 1 through the CPU bus 109
25, and the timing signal is generated according to this condition. The various conditions required here are, for example, when a one-dimensional line sensor camera is used in the imaging device 1 or 2, the reading cycle and the image input position (the pixel position to be input from the line sensor camera) according to the number of pixels. Includes information that directs etc. The dark correction means the image pickup apparatus 1
Alternatively, the offset component included in the input signal from 2 is subtracted at the time of image input, and reference data is input in advance to obtain the subtraction amount to be dark-corrected. Shading correction refers to shading components included in an input signal from the image pickup device 1 or 2 from dark-corrected image data (pixel sensitivity unevenness in the case of a line sensor camera, illumination unevenness for imaging a printed matter). Which means the component to be added) is divided when the image is input,
Reference data is input in advance to obtain a division value for shading correction. Therefore, the image input units 1 and 2 have a mode for transferring image data to the image bus 110 and a mode for inputting data for the dark correction unit 121 and the shading correction unit 122.

Next, the operation of each of the image memories 103 to 106 will be described.

FIG. 4 is a block diagram showing the internal structure of each of the image memory units 103 to 106.

In this image memory unit, memory access to the memory unit 140 is made possible from the CPU bus 109 and the image bus 110. For this reason,
The access selection unit 141 uses the memory unit 140 as necessary.
You can switch the access mode to. When the memory unit 140 is accessed from the image bus 110 (when writing to the image memory), the timing generation unit 142
Outputs a control signal for controlling the data collection unit 143 and the address generation unit 144 according to the control signal 145 from the image bus 110 to access the memory unit 140 through the access selection unit 141. The data collection unit 143 stores the image data 146 from the image bus 110 in the memory unit 140.
A plurality of image data are collected so as to match the data bus width of, and output to the memory unit 140 through the access selection unit 141. The address generation unit 144 is the timing generation unit 1
According to the control of 42, the storage address of the memory section 140 is increased every writing.

A CPU bus interface 147 outputs control signals, data and addresses from the host computer 5 input from the CPU bus 109 to the access selection unit 141. The access selection unit 141
The control signal, data, and address output to the memory unit 140 are signals from the CPU bus interface 147, or the timing generation unit 142, the data collection unit 1
43 and the signal from the address generation unit 144 are selected.

FIG. 5 is a diagram for explaining the write timing from the image bus 110 in the image memory units 103 to 106.

Now, referring to FIG. 6, a case where an image of the printed matter 500 is input to the image pickup apparatus 1 by using a one-dimensional line sensor will be described. The print object 500 to be input is input to the image memories 103 and 104 as a two-dimensional image while moving relatively to the one-dimensional line sensor in a direction (sub-scanning direction) perpendicular to the line direction. To do. 1
The number of pixel data for one line of the three-dimensional line sensor is H, 1
The number of scans of the three-dimensional line sensor is V, and the image input unit 10
When inputting image data of the image input area 501 (mesh line portion) with 1, the memory capacity of each of the image memory units 103 and 104 is M bytes, and the image data amount to be input is N (=
(H × V) bytes and 2M>N> M.

In FIG. 5, reference numeral 160 denotes a bus transfer clock, which is issued by the image input unit 101 and
It is input to the image memory units 103 and 104 through 0.
The image valid signal 161 is similarly issued from the image input unit 101, becomes low level and is output to the image bus 110 when the area 501 in FIG. 6 is valid, and the image bus data 162 is output.
Is the data to be stored in the image memory unit 103,
Notify 104. The image bus data 162 is
The image data output from the image input unit 101 is shown. Now, each pixel of the image data is represented by 8 bits, and the bit width of the data bus of the memory unit 140 is 32 bits.

Thus, the image data output by the image input unit 101 is stored in the image memory 103. At this time, the timing generation unit 142 causes the bus transfer clock 16
0, the data collection unit 14 based on the image valid signal 161.
The latch signals 163 to 166 are issued to No. 3. As a result, the data collection unit 143 is set to 3 in 4 clock cycles.
The image data of 2 bits (for 4 pixels) is latched. When the 32-bit latch is completed, the timing generation unit 142 issues a write signal 167 to the memory unit 140 through the access selection unit 141. Address generator 1
44 is a memory unit 140 through the access selection unit 141.
The memory address is issued to the memory unit 140, but when the writing to the memory unit 140 is completed, the address is prepared for the next writing.

In this way, the writing of the image data to the image memory 103 is repeated, and when the number of written bytes reaches M, the timing generation unit 142 of the image memory unit 103
An overflow signal 168 indicating that the data in the memory section 140 is full is output. Thus, the data from the 0th byte to the (M-1) th byte is stored in the image memory unit 103.

Next, the image memory section 104 includes an image valid signal 161, a bus transfer clock 160, and the image memory section 10.
It is judged from the overflow signal 168 issued by the No. 3 whether or not the image data of the image bus 110 is to be written, and the writing operation is started after the image memory unit 103 becomes full, for example, this time.

In the write operation to the image memory section 104, the write operation to the memory section 140 is repeated every 4 bytes as described above (first byte latch signal 169 to fourth byte).
Byte latch signal 172 and memory write signal 17
3) From the Mth byte, which is the next byte of the image data already stored in the image memory unit 103, to the (N-1) th byte, which is the end of the entire image area, are the image memory unit 1
It is stored in 04. In general, the number of bytes N to be written in the image memory unit is not always a multiple of 4, so it is conceivable that there will be an unwritten portion. The remaining data is stored in the data collection unit 143 and can be read by the host computer 5 as needed. Further, the write start memory address from the image bus, the setting as to whether or not writing is permitted by the write valid signal from the image bus, the write status information, etc. are appropriately controlled from the host computer 5 via the CPU bus.

By the above operation, for example, the image data obtained by reading the print image area # 1 (502) shown in FIG. 6 is stored in the image memory unit 103, and the image data of the area # 2 (503) is stored in the image memory unit 104. It The host computer 5 then uses the image memory units 103 and 10 as necessary.
By reading the image data stored in No. 4, image processing for image evaluation of the printed matter can be executed.

FIG. 7 is a diagram showing the configuration of the image bus 110 described above. The image bus 110 includes the processing units 181 to 184.
The switching unit 180 is provided between the two. The processing units 181 to 184 include the above-mentioned image input unit, image memory unit, and various arithmetic units.

The switching unit 180 is characterized in that the control signal line, the image data line, and the like can be individually connected or released. As a result, FIG.
In, for example, the processing unit 181 can be directly connected to the processing unit 182 to exchange data. Further, for example, in the case of the configuration as shown in FIG. 2, when it is desired to input image data at the same timing and with the same resolution by using the two image pickup devices 1 and 2, the image memory unit 104 and the image input unit 102.
The switching unit 180 in the image bus 110 during the period separates the overflow signal and the area valid signal from the image data section and the control signal, and connects the bus transfer clock and the synchronization signal to thereby transfer the image data from the image pickup apparatus 1. The image data from the imaging device 2 can be stored in the image memory unit 104 via the image input unit 102 while being stored in the image memory unit 103 via the image input unit 101.

An example of such image reading will be described with reference to FIG. The widths of the respective line sensors of the image pickup apparatuses 1 and 2 are set to H1 and H2, the area 511 of the original image 510 is read by the image pickup apparatus 1, and the original image 510 is read by the image pickup apparatus 2.
Read the area 512 in the right half of. At this time, image bus 1
The switching unit 180 of 10 connects the image input unit 101 and the image memory unit 103, and the switching unit 180 of the image bus 110 connects the image input unit 102 and the image memory unit 104.
And connect. However, at this time, the switching unit 180 disconnects the image data signal from the overflow signal and the area valid signal of the control signal, and connects the bus transfer clock and the synchronization signal.

The present invention may be applied to either a system composed of a plurality of devices or an apparatus composed of a single device. Further, it goes without saying that the present invention can also be applied to the case where it is achieved by supplying a program for implementing the present invention to a system or an apparatus.

As described above, according to this embodiment, the overflow signal is provided in the image memory unit,
Efficient image input can be realized, and the memory capacity can be increased or decreased as necessary.

By collecting a plurality of pixels and then performing the writing operation to the image memory, it is possible to write the image data to the memory which is not so high speed with respect to the image data transferred at a high speed. As a result, a large amount of memory is required when it is necessary to input as an image of a large area such as a printed matter, so that there is an advantage that the cost can be significantly reduced by using a low-speed and inexpensive memory.

Further, by providing the image bus with a switching unit, it is possible to flexibly deal with the input of image data from a plurality of image pickup devices, and it becomes possible to input image data from a plurality of image pickup devices at the same timing. Simplification of processing,
Diversification of the device configuration can be achieved.

[0037]

As described above, according to the present invention, there is an effect that the original image can be flexibly read and stored at a low price.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a print evaluation apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an image processing unit according to the present exemplary embodiment.

FIG. 3 is a block diagram showing a configuration of an image input unit of this embodiment.

FIG. 4 is a block diagram showing a configuration of an image memory unit of the present embodiment.

FIG. 5 is a diagram showing an example of transfer timing of image data in the image memory unit of the present embodiment.

FIG. 6 is a diagram showing an example in which a print image is divided into a plurality of areas and input to a memory.

FIG. 7 is a diagram showing a configuration of an image bus of this embodiment.

FIG. 8 is a diagram for explaining an example of reading and inputting a document image using a plurality of imaging devices.

[Explanation of symbols]

1, 2 imaging device 4 Image processing section 5 Host computer 101, 102 image input section 103-106 image memory unit 109 CPU bus 110 image bus 125 timing signal generator 140 memory section 141 Access selection section 142 Timing generation unit 143 Data collection section 144 address generator

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-5-83494 (JP, A) JP-A-2-16684 (JP, A) JP-A-4-232574 (JP, A) JP-A-56- 65565 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G06T 1/00-1/60

Claims (4)

(57) [Claims] 1. By relatively scanning the original image ,
One or more imaging hands are used to scan a given image area.
An image input device that can be performed using a plurality of stages, is provided corresponding to each of the plurality of image pickup means, inputs image data from the image pickup means, and outputs the image data to an image bus. The image input means, a plurality of storage means for inputting and storing the image data via the image bus, and connection / disconnection of control signal lines included in the image bus are disconnected.
Switch the connection between the plurality of storage means by switching
And a switching means capable of changing the switching means, and by switching the switching means, one image pickup means is obtained.
When reading by reading, the first of the plurality of storage means is used.
1 When the image data amount in the storage means exceeds a predetermined amount
Stored in the second storage means and read by the plurality of imaging means
Image from each of the plurality of image pickup means.
The image data is recorded in a different storage means corresponding to the image pickup means.
An image input device characterized by remembering . 2. The stored image data is stored in the first storage means.
When the amount of data exceeds the specified amount, an overflow signal is output.
To force it to be stored in the second storage means.
The image input according to claim 1, wherein the image input is replaced.
Force device. 3. The reading is performed by the plurality of image pickup means.
In this case, the switching means synchronizes the control signal lines.
The image input device according to claim 1, wherein a signal line is connected . 4. The reading is performed by the plurality of image pickup means.
In this case, image data from the plurality of image pickup means are
To store in the corresponding storage means
The image input device according to claim 1, wherein the image input device is provided.