JP2001111793A - Image reader, image read method and memory medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly determine read conditions for regular scanning. SOLUTION: After a first preliminarly scanning (S0010) is executed, a histogram of signals of a read image is generated (S0011), whether or not the histogram has an offset is decided (S0012), when any offset is in existence, a storage time of a CCD shutter is set again, the subscanning direction (direction of film movement) is reversed (S0013, S0014), and the preliminarly scnning is executed again (S0010).

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, an image reading method, and a memory medium. More particularly, the present invention relates to a preliminary scan of a document image, and determines a reading condition at the time of a main scan based on the result. The present invention relates to an image reading device and an image reading method for executing a main scan according to a reading condition, and a memory medium for controlling the operation.

[0002]

2. Description of the Related Art As a film scanner for converting an image on a photographic film into an electric image signal and outputting it to a computer or the like, in order to read the image with high quality, an image of a frame to be read is read prior to a main scan. Optimal reading conditions (eg, gamma coefficient, image storage time, image reading speed,
Lamp light intensity, analog gain value, digital gain value, etc.)
In some cases, a preliminary image reading (pre-scan or preliminary scan) is performed to determine the value.

[0003]

However, since the optimal reading conditions in the pre-scan differ depending on the film, the image to be read, and the like, the pre-scan is performed under inappropriate conditions, and the pre-scan is performed based on the result. In some cases, scanning conditions for scanning are determined. In this case, the main scan is performed under inappropriate conditions.

The present invention has been made in view of the above background, and has as its object to appropriately determine, for example, reading conditions for a main scan.

[0005]

An image reading apparatus according to a first aspect of the present invention preliminarily scans a document image, determines reading conditions at the time of main scanning based on a result of the preliminary scanning, and according to the reading conditions. An image reading apparatus for performing a main scan, comprising: an image pickup unit;
The document image is preliminarily scanned by the image capturing unit while relatively moving in the direction, and the image capturing unit is moved relatively to the image capturing unit in a second direction opposite to the first direction. Preliminary scanning means for preliminary scanning of the original image, determining means for determining whether the preliminary scanning has been performed under appropriate reading conditions, and determining whether the preliminary scanning has not been performed under appropriate reading conditions. And a control means for changing a reading condition, inverting a relative movement direction of the document image with respect to the imaging unit, and causing the preliminary scanning means to execute the preliminary scanning again.

In the image reading apparatus according to the first aspect of the present invention, for example, when the control means causes the preliminary scan means to execute the preliminary scan again, the signal value of the read image obtained by the preliminary scan again It is preferable to determine the reading conditions for the preliminary scan again so that the histogram becomes appropriate.

In the image reading apparatus according to the first aspect of the present invention, for example, when the control unit causes the preliminary scanning unit to execute the preliminary scanning again, the luminance of the read image obtained by the preliminary scanning again is reduced. It is preferable to determine the reading conditions for the preliminary scan again so as to be appropriate.

In the image reading apparatus according to the first aspect of the present invention, for example, it is preferable that the original image is an image formed on a film.

An image reading apparatus according to a second aspect of the present invention scans a document image preliminarily, determines reading conditions at the time of main scanning based on a result of the preliminary scanning, and executes an image to perform a main scanning according to the reading conditions. A reading device, an imaging unit, preliminary scanning means for preliminary scanning an original image by the imaging unit, determination means for determining whether or not the preliminary scanning by the preliminary scanning means has been performed under appropriate reading conditions; When it is determined that the scanning is not performed under appropriate reading conditions, a control unit that causes the preliminary scanning unit to prescan the original image again is provided.

[0010] In the image reading apparatus according to the second aspect of the present invention, for example, when the control means causes the preliminary scanning means to execute the preliminary scanning again, the signal value of the read image obtained by the preliminary scanning again. It is preferable to determine the reading conditions for the preliminary scan again so that the histogram becomes appropriate.

In the image reading apparatus according to the second aspect of the present invention, for example, when the control means causes the preliminary scan means to execute the preliminary scan again, the control unit may adjust the luminance of the read image obtained by the preliminary scan again. It is preferable to determine the reading conditions for the preliminary scan again so as to be appropriate.

In the image reading apparatus according to the second aspect of the present invention, for example, it is preferable that the original image is an image formed on a film.

In an image reading method according to a third aspect of the present invention, an original image is preliminarily scanned, reading conditions at the time of main scanning are determined based on a result of the preliminary scanning, and an image for which main scanning is executed in accordance with the reading conditions is determined. A reading method, comprising: a first preliminary scanning step of preliminarily scanning an original image by the imaging unit while relatively moving the original image in a first direction with respect to an imaging unit; and a first preliminary scanning step. Based on the read image, it is determined whether or not to execute the preliminary scan again. If the preliminary scan is to be performed again, the original image is transmitted to the imaging unit in a direction opposite to the first direction. A second preliminary scanning step of preliminarily scanning the document image by the imaging unit while relatively moving in two directions.

In an image reading method according to a fourth aspect of the present invention, an original image is preliminarily scanned, reading conditions at the time of main scanning are determined based on a result of the preliminary scanning, and image scanning is performed according to the reading conditions. A reading method, comprising: a preliminary scanning step of preliminary scanning an original image by an imaging unit; a determining step of determining whether the preliminary scanning in the preliminary scanning step has been performed under appropriate reading conditions; And controlling the pre-scanning step again when it is determined that the pre-scanning step is not performed.

[0015] A memory medium according to a fifth aspect of the present invention comprises:
A preliminary scan of a document image, a reading condition at the time of a main scan is determined based on the result, and a memory medium storing a control program for executing a main scan according to the reading condition, wherein the control program includes: A first preliminary scanning step of preliminarily scanning the original image by the imaging unit while relatively moving the original image in the first direction with respect to the imaging unit, based on the read image obtained in the first preliminary scanning step; Then, it is determined whether or not to execute the preliminary scan again. When the preliminary scan is performed again, the original image is relatively moved with respect to the imaging unit in a second direction opposite to the first direction. And a second pre-scanning step of pre-scanning the document image by the image pickup unit while moving the document image to the original.

A memory medium according to a sixth aspect of the present invention comprises:
A preliminary scan of a document image, a reading condition at the time of a main scan is determined based on the result, and a memory medium storing a control program for executing a main scan according to the reading condition, wherein the control program includes: A pre-scanning step of pre-scanning the original image by the imaging unit; a determining step of determining whether or not the pre-scanning in the pre-scanning step is performed under appropriate reading conditions; and And a control step of re-executing the preliminary scanning step when the judgment is made.

[0017]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

Although this embodiment relates to a film scanner for reading an optical image of a long film housed in a cartridge, the present invention relates to, for example, a film cut every predetermined number of frames or a film cut every single frame. The present invention can also be applied to a film scanner that reads an optical image of a film.

FIG. 1 is a diagram showing a schematic configuration of a film scanner according to a preferred embodiment of the present invention. The film scanner 100 is, for example, a computer (for example, a personal computer) connected to the monitor 300
200 can be used.

Reference numeral 101 denotes a cold cathode tube as an illumination light source. Reference numeral 102 denotes a cartridge 141 containing a film.
Is a film adapter that can move in the Y direction. Reference numeral 115 denotes a sub-scanning motor (for example, a stepping motor) for moving the film adapter 102 in the sub-scanning direction (Y direction). Reference numeral 116 denotes a sub-scanning motor 1 according to a command from the system controller 111.
15 is a sub-scanning motor driver for driving the motor 15. 1
Reference numeral 17 denotes a sub-scanning position detecting unit for detecting a sub-scanning reference position, for example, detecting a protrusion of the film adapter 102 using a photo interrupter.

Reference numeral 103 denotes an imaging lens system. 104
Denotes a CCD linear image sensor (hereinafter, simply referred to as a linear image sensor) as an image sensor. Here, the linear image sensor 104 is arranged so that the Z direction is the longitudinal direction. Due to this positional relationship, the main scanning direction (Z direction), which is the longitudinal direction of the linear image sensor 104, and the sub-scanning direction (Y direction), which is the moving direction of the film adapter 102, form a right angle.

In the final image reading (final scan), after searching for a relevant frame of the film stored in the cartridge 141 held by the film adapter 102, the entire film adapter 102 is scanned by the sub-scanning motor 115 in the Y direction. By moving it to

Reference numeral 105 denotes a focus fixing member, which is movable in the optical axis direction (X direction) with the linear image sensor 104 fixed near the image plane of the imaging lens system 103. A black level correction circuit 106 amplifies an analog image signal output from the linear image sensor 104 at a set amplification factor and adjusts a black level.
Reference numeral 107 denotes an A / D converter, which is a black level correction circuit 10
The analog signal processed in step 6 is converted into a digital signal.

Reference numeral 108 denotes an image processing unit which performs image processing (for example, gamma correction, color correction, compression, etc.), control of driving pulses of the linear image sensor 104, control of the electronic shutter of the linear image sensor 104, and the like. Do. The image processing unit 108 includes, for example, a gate array, and can perform various types of processing at high speed. 109
Is a line buffer for temporarily storing image data. The line buffer 109 is composed of, for example, a general-purpose random access memory.

Reference numeral 110 denotes an interface unit, which is used to communicate with the computer 200. The interface unit 110 is composed of, for example, a SCSI controller. A system controller 111 includes a memory medium storing a control program for the film scanner 100 and a CPU.
Each part is controlled according to an instruction from 0.

Reference numeral 112 denotes a D / A converter for supplying a reference voltage to the black level correction circuit 106. 11
3 is a system controller 111, an image processing unit 10
8, line buffer 109, interface unit 11
0, C connecting RAM 122 and gamma RAM 130
It is a PU bus and is composed of an address bus, a data bus, and a control bus.

Reference numeral 118 denotes a light source lighting circuit (for example, an inverter circuit) for lighting the light source (cold cathode tube) 101.
It is. Reference numeral 120 denotes a drive signal for driving the linear image sensor 104, and 121 denotes a black level correction circuit 10.
6 is a sample-hold control signal for sample-holding the signal supplied from 6.

Reference numeral 122 denotes a RAM that provides a working area for image processing, and is used for temporarily storing various data such as prescanned images, creating histograms, shading correction, and color data synthesis, and image data. Is done.

Reference numeral 123 denotes a focus motor that moves the focus fixing member 105 in the optical axis direction. Reference numeral 124 denotes a focus motor driver that supplies a drive signal to the focus motor 123. Reference numeral 125 denotes a focus that detects an initial position of the focus fixing member 105. It is a position detection unit. A gamma RAM 130 stores a gamma curve for gamma correction.

In the film adapter 102, 140
Is a motor for winding and rewinding the film stored in the film cartridge 141. The motor is engaged with the spool 200 of the film cartridge 141, and conveys the film by forward and reverse drive. The motor 140 drives the film at a high speed for designated frame advancement, all-frame reduction reading, or reading of magnetic information and optical information, and for pre-scan processing for obtaining image reading conditions of the corresponding frame. Used for Reference numeral 142 denotes a controller which receives a command with the system controller 111 via the communication line 143, transmits a status, and controls the motor 140 according to the content of the command.

Reference numeral 144 denotes an optical sensor for optically detecting a perforation hole in the film. An optical sensor 145 detects optical information such as optical information written on an edge of the film. Reference numeral 146 denotes a recording / reproducing magnetic head as a magnetic information recording / detecting unit for detecting magnetic information written on the edge of the film or recording magnetic information.

Reference numeral 143 denotes a communication line (for example, a serial communication line) for exchanging information between the system controller 111 and the controller 142 of the film adapter 102.

In FIG. 1, the direction A is the winding direction (the direction in which the film 201 is unwound from the cartridge 141), and the direction B is the rewinding direction (the direction in which the film 201 is stored in the cartridge 141). Film 201
Is sent out of the cartridge 141 by the rotation of the spool 200. The film is held by a film winding section for winding the film, a capstan and a pinch roller arranged in a film transport path between the cartridge 141 and the winding section, and fed at a constant speed. These operations are processed by the controller 142 of the film adapter 102.

A monitor 300 is connected to the computer 114 and displays images and characters.

FIG. 5A is a flowchart showing the operation of the film scanner 100. The operation shown in this flowchart is controlled by the CPU based on a control program stored in a memory medium, for example.

When the power is turned on in step S2001, the film scanner 100 is turned on in step S2002.
Performs the initial setting. In step S2003, the film scanner 100 waits for connection to the computer 200, and when connected to the computer 200, starts communication with the computer 114 in step S2004.

In step S2005, the computer 1
And waits for a command from step S14.
At 006, the received command is analyzed and the corresponding process is executed. Here, the film scanner 100
Transmits the execution result of the command to the computer 114 sequentially, and waits for reception of the next command.

FIG. 5B is a flowchart showing the operation of the computer 200. When the power is turned on in step S2007, in step S2008, the computer 200 searches for and connects to the film scanner 100 on the communication bus. In step S2010, the computer 200 activates application software including driver software. In step S2011, the application software of the computer 200 confirms whether or not there is an instruction from the operator.
At 12, a command corresponding to the instruction is created and transmitted to the film scanner 100 via the driver software. In step S2013, the application software of the computer 200 receives the command execution result from the film scanner 100 via the driver software, and provides the command execution result to the operator using the screen of the monitor 300 (command response processing). When the process in step S2013 ends, the process returns to step S2011, and the application software waits for the next instruction from the operator.

FIG. 6 is a flowchart showing details of the command execution processing (S2006) of FIG. 5A.

In step S2101, the film scanner 100 determines whether the received command is a pre-scan command. If the received command is a pre-scan command, the film scanner 100 executes pre-scan processing in step S2102.

In step S2103, the film scanner 100 determines whether the received command is a focus adjustment command. If the received command is a focus adjustment command, the film scanner 100 executes focus adjustment processing in step S2104.

In step S2105, the film scanner 100 determines whether the received command is a main scan command. If the received command is a main scan command, the film scanner 100 executes main scan processing in step S2106.

In step S2107, the film scanner 100 determines whether the received command is an eject command. If the received command is an eject command, the film scanner 100 ejects the cartridge 141 in step S2108.

In step S2109, the film scanner 100 determines whether the received command is a film type command. If the received command is a film type command, the film scanner 100 determines the film type specified by the command (for example, negative, positive, Monochrome).

Similarly, in step S2111, the film scanner 100 determines whether the received command is a predetermined command. If the received command is a predetermined command, in step S2112, the process corresponding to the command is performed. Execute.

If the received command is an undefined command, the film scanner 100 proceeds to step S21.
At 13, an abnormal command process is executed.

When the processing corresponding to each command is completed,
The film scanner 100 notifies the computer 200 of the end of the execution, and executes the command execution process (S200
6) is ended.

FIG. 7 shows the prescan processing (S21) of FIG.
It is a flowchart which shows the detail of 02). Here, the film adapter 10 of the film scanner 100 is used.
2 will be described assuming that a film is already loaded.

In step S0001, the system controller 111 of the film scanner 100 causes the film adapter 102 to wind the film, and moves the frame of the film to the reading start position.

In steps S0002 to S0009, the system controller 111 sets reading conditions (parameters) for executing the first prescan.

In step S0002, the system controller 111 sets the amount of lamp light in the light source lighting circuit 118. In step S0003, the system controller 111 issues a lighting instruction to the light source lighting circuit 118 to light the light source 101. In step S0004, the system controller 111
The exposure time of No. 4 is set in the image processing unit 108. In step S0005, the system controller 111 sets the accumulation time of the linear image sensor 104 by the electronic shutter in the image processing unit 108. Step S0006
Then, the system controller 111 sets the gamma curve in the gamma RAM 130. In step S0007, the system controller 111 sets the analog gain value and the digital gain value in the image processing unit 108.

In step S0008, the system controller 111 communicates with the controller 142 of the film adapter 102 to set the film in the winding direction. In step S0009, the system controller 1
11 is a controller 142 of the film adapter 102
Speed of film winding (sub-scanning speed)
Set. Thus, the setting of the reading conditions at the time of the first pre-scan is completed.

In step S0010, the system controller 111 communicates with the controller 142 of the film adapter 102 to execute an operation (pre-scan) of reading an image of a corresponding frame of the film while winding the film. R obtained by reading the image of the relevant frame,
The G and B image data are stored in the RAM 122.

In step S0011, the system controller 111 stores the R, G, and B stored in the RAM 122.
A histogram of signal values is created for each of the R, G, and B image data based on the image data of, and stored in a free area of the RAM 122.

In step S0012, the system controller 111 determines, based on the histogram stored in the RAM 122, whether the reading conditions during the pre-scan were inappropriate. Specifically, in this embodiment, in step S0012, the system controller 111 determines whether the histogram stored in the RAM 122 has a bias. For example, if the frequency of the maximum possible value of the signal value of the image data (for example, “255” when the image data is 8-bit data) is 1% or more of the total number of sampling pixels (exceeding the light amount), the bias is generated. It is determined that there is.

If it is determined that there is a bias in the histogram (when the exposure amount is not appropriate), the process proceeds to step S0013.
Then, the system controller 111 adjusts the accumulation time of the linear image sensor 104 by the electronic shutter so as to correct the bias and resets the accumulation time in the image processing unit 108. In step S0014, the system controller 111
By communicating with the controller 142 of the film adapter 102, the moving direction of the film is set to the reverse direction (if the previous setting was the winding direction, the rewinding direction). here,
In step S0013, other reading conditions (for example, the light amount of the light source 101, the exposure time of the linear image sensor 104, etc.) may be adjusted and reset. After the execution of steps S0013 and S0014, the process proceeds to step S0010, and the second prescan is executed while moving the film in the direction opposite to the moving direction of the film in the previous prescan according to the reset reading conditions.

Here, the reading at the time of the first prescan is performed so that a histogram in which the bias is within an allowable range can be obtained by the second prescan (that is, appropriate reading conditions are set). By setting the conditions, an appropriate image reading condition can be set by a maximum of two pre-scans.

If it is determined in step S0012 that the deviation of the histogram is within the allowable range, the system controller 111 issues a turn-off command to the light source lighting circuit 118 to turn off the light source 101 in step S0015.

In step S0016, the system controller 111 moves the corresponding frame of the film to the initial position as necessary. Here, when an appropriate histogram is obtained in one pre-scan (that is, when an appropriate image reading condition is set), the film is rewound, and an appropriate histogram is obtained in the second pre-scan. Is obtained, it is not necessary to move the film because the film has already been rewound to the initial position.

In step S2514, the system controller 111 calculates reading conditions for the main scan based on the histogram data stored in the RAM 122 according to a predetermined algorithm.

As described above, according to this embodiment,
For example, if there is a bias in the histogram of the signal values of the image data obtained by the pre-scan due to excessive light amount or insufficient light amount, that is, if the read conditions in the pre-scan are inappropriate, By changing and performing the pre-scan again, an appropriate histogram can be obtained, and as a result, an appropriate reading condition for the main scan can be determined. Therefore, the quality of the final read image obtained by the main scan can be improved.

Further, according to this embodiment, the second and subsequent prescans (for example, the second time) are executed while moving the film in the direction opposite to the film moving direction at the time of the previous prescan. Accordingly, the number of times the film is moved (the number of reciprocations) can be reduced, and the efficiency of a series of prescan processing can be increased. Accordingly, the mechanical load applied to the film, the cartridge 141, and the like can be reduced.

FIG. 8 shows the main scan processing (S210) in FIG.
It is a flowchart which shows the detail of 6). In this embodiment, at the time of pre-scan, the film adapter 1
The sub-scan is performed by winding or rewinding the film at high speed by the motor 140 of No. 02. Further, at the time of the main scan, after the frame is moved to a predetermined position by the film adapter 102, the entire film adapter 102 is relatively moved with respect to the linear image sensor 104 by the scanning motor 115 capable of high-precision scanning. Thus, sub-scanning is performed. However, the sub-scanning can be performed by the scanning motor 115 at the time of the pre-scan as well as the time of the main scan.

Prior to the main scan processing shown in FIG. 8, the corresponding frame of the film has been positioned at a predetermined position in step S0016 in FIG.

In step S2501, the system controller 111 controls the scanning motor 115 to move the film adapter 102 so that the corresponding frame of the film coincides with the reading start position in the sub-scanning direction.

In steps S2502 to S2509, the system controller 111 executes the prescan processing (S2
102, the reading conditions calculated in FIG. 7) are set in order. In step S2502, the system controller 111
Sets the lamp light quantity in the light source lighting circuit 118. In step S2503, the system controller 111
A lighting command is issued to the light source lighting circuit 118 to light the light source 101. In step S2504, the system controller 111 sets the exposure time of the linear image sensor 104 in the image processing unit. In step S2505, the system controller 111 sets the accumulation time of the linear image sensor 104 by the electronic shutter in the image processing unit 108. In step S2506, the system controller 111 stores the gamma curve in the gamma RAM
Set to 130. In step S2507, the system controller 111 sets the value of the analog gain in the image processing unit 108. In step S2508, the system controller 111 sets the value of the digital gain in the image processing unit 108. In step S2509, the system controller 111 sets the speed of the sub-scanning motor 115. Thereby, the reading conditions at the time of the main scan are set.

In step S2510, the system controller 111 executes an operation of controlling the sub-scanning motor 115 and reading the image of the corresponding frame of the film while moving the film adapter 102.

When the image reading is completed, step S
In step 2511, the system controller 111 issues a turn-off command to the light source lighting circuit 118 to turn off the light source 101. In step S2512, the system controller 1
11 moves the film adapter 102 to the initial position by the sub-scanning motor 115 while monitoring the sub-scanning position detecting unit 117.

Next, a specific example of the prescan processing shown in FIG. 7 will be described.

As a method of adjusting the overall luminance (or histogram) of the image data to be obtained by the prescan processing, for example, a method of changing the light amount of the light source 101, a method of changing the exposure time of the linear image sensor 104,
There are a method of changing the accumulation time of the shutter of the linear image sensor 104, a method of changing the gain (analog gain) of the analog amplifier of the black level correction circuit 106, and the like.

In this embodiment, the overall luminance of the image data to be obtained by the prescan processing is adjusted by a method of changing the accumulation time of the linear image sensor 104 by the shutter.

In the first pre-scan, the exposure time of the linear image sensor 104 is set to, for example, 12.96 msec for a negative film. The moving speed of the film is also set according to this value.

The film adapter 102 has a controller 142 mounted thereon. The controller 142 drives the motor 140 in the film adapter 102 while communicating with the system controller 111 via the serial communication line 143, and is stored in the cartridge 141. Control of the winding and rewinding of the film.

In the first pre-scan, the accumulation time by the electronic shutter of the linear image sensor 104 is set to a predetermined time, the film is fed by the winding operation by the motor 140, and the image of the corresponding frame is read. The image data is converted into digital data by the / D converter 107 and stored in the RAM 122 for each of the red (R), green (G), and blue (B) image data via the image processing unit 108.

The system controller 111 of the film scanner 100 controls the R, G, B stored in the RAM 122
Create a histogram of the image data. FIG. 2 is an example of a histogram created by the system controller 111. In FIG. 2, the horizontal axis represents the signal value of the image data. The vertical axis is the appearance frequency of the signal value. In this embodiment, the image data is composed of 8 bits, and the horizontal axis is from 0 to 255.
It is. The number of samples is 30,000 pixels for each of R, G, and B colors, and the maximum value on the vertical axis is 30,000.

The system controller 111 of the film scanner 100 obtains the average density, highlight point, shadow point and the like based on the histogram shown in FIG. The image reading conditions such as the speed, the exposure time of the linear image sensor 104, the accumulation time by the electronic shutter, the light amount of the light source 101, the analog gain value, and the digital gain value are calculated (S0017).

Here, when the histogram of the image data obtained in the first pre-scan is concentrated around the signal value "255" as shown in FIG. 3, for example, the system controller 111 biases the histogram. If it is determined that there is (Yes in S0012), the accumulation time of the electronic shutter of the linear image sensor 104 is shortened (for example, reduced to 倍) (S0013), and the sub-scanning movement direction is reversed (S0013). S0014) A second pre-scan is performed. The histogram of the image data obtained by the second pre-scan has no bias.

On the other hand, when the histogram of the image data obtained in the first pre-scan is concentrated near the signal value "0" as shown in FIG. 4, for example, it is determined that the histogram has a bias. (“Yes” in S0012), the system controller 111
The storage time by the electronic shutter of No. 4 is lengthened (for example, doubled) (S0013), the sub-scanning movement direction is reversed (S0014), and the second prescan is performed. The histogram of the image data obtained by the second pre-scan has no bias.

The above is an example in which the present invention is applied to an image reading apparatus that reads transmitted light from a document.
The present invention can also be applied to an image reading device that reads reflected light from a document.

The present invention may be applied to a system composed of a plurality of devices or to a single device.

Further, an object of the present invention is to supply a storage medium (or a recording medium) on which a program code of software for realizing the functions of the above-described embodiments is recorded to a system or an apparatus, and a computer (a computer) of the system or the apparatus. It is needless to say that the present invention can also be achieved by a CPU or an MPU) reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium implements the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention. Also,
When the computer executes the readout program code, not only the functions of the above-described embodiments are realized, but also the operating system (OS) running on the computer based on the instructions of the program code.
It goes without saying that a case where the functions of the above-described embodiments are implemented by performing some or all of the actual processing, and the processing performs the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written in a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the program code is read based on the instruction of the program code. Needless to say, the CPU included in the function expansion card or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0083]

According to the present invention, for example, reading conditions for a main scan can be appropriately determined.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a film scanner according to a preferred embodiment of the present invention.

FIG. 2 is an example of a histogram created by a system controller of a film scanner.

FIG. 3 is an example of a histogram created by a system controller of a film scanner.

FIG. 4 is an example of a histogram created by a system controller of the film scanner.

FIG. 5 is a flowchart showing an operation (a) of the film scanner and an operation (b) of the computer.

FIG. 6 is a command execution process of FIG. 5A (S2006).
6 is a flowchart showing details of the process.

FIG. 7 is a flowchart illustrating details of a pre-scan process (S2102) in FIG. 6;

FIG. 8 is a flowchart illustrating details of a main scan process (S2106) in FIG. 6;

Claims (12)

[Claims] An image reading apparatus that performs a preliminary scan of a document image, determines a reading condition at the time of a main scan based on a result of the preliminary scanning, and executes a main scan in accordance with the reading condition, comprising: an imaging unit; The document image is preliminarily scanned by the imaging unit while the document image is relatively moved in the first direction with respect to the unit, and the document image is moved to the imaging unit in a second direction opposite to the first direction. Preliminary scanning means for preliminarily scanning a document image by the imaging unit while relatively moving; determining means for determining whether or not the preliminary scanning has been performed under appropriate reading conditions; If it is determined that the scanning has not been performed, the reading condition is changed, the direction of movement of the document image relative to the image pickup unit is reversed, and the preliminary scanning unit is again scanned by the preliminary scanning unit. Image reading apparatus characterized by comprising a control means for executing. 2. The control device according to claim 1, wherein when the preliminary scan is performed again by the preliminary scan, the preliminary scan is performed again so that a histogram of signal values of a read image obtained by the preliminary scan becomes appropriate. The image reading apparatus according to claim 1, wherein a reading condition for the image is determined. 3. The control unit according to claim 1, wherein the control unit controls the pre-scanning unit to execute the pre-scanning again so that the luminance of the read image obtained by the pre-scanning becomes appropriate. The image reading apparatus according to claim 1, wherein a reading condition is determined. 4. The image reading apparatus according to claim 1, wherein the document image is an image formed on a film. 5. An image reading apparatus which performs a preliminary scan of a document image, determines a reading condition at the time of a main scan based on a result of the preliminary scanning, and executes a main scan in accordance with the reading condition. A preliminary scanning unit for preliminary scanning the original image by the unit; a determining unit for determining whether the preliminary scanning by the preliminary scanning unit is performed under appropriate reading conditions; and determining that the preliminary scanning is not performed under appropriate reading conditions. Control means for causing the preliminary scanning means to preliminarily scan the document image again when the image reading is performed. 6. The control unit according to claim 1, wherein when the preliminary scan is performed again by the preliminary scan, the preliminary scan is performed again so that a histogram of signal values of a read image obtained by the preliminary scan becomes appropriate. The image reading apparatus according to claim 5, wherein a reading condition for the image reading is determined. 7. The control device according to claim 1, wherein the control unit controls the preliminary scan unit to execute the preliminary scan again so that the luminance of the read image obtained by the preliminary scan becomes appropriate. The image reading apparatus according to claim 5, wherein a reading condition is determined. 8. The image reading apparatus according to claim 5, wherein the document image is an image formed on a film. 9. An image reading method for preliminarily scanning a document image, determining a reading condition at the time of a main scan based on a result of the preliminary scanning, and executing a main scan in accordance with the reading condition. A first preliminary scanning step of preliminary scanning the original image by the imaging unit while relatively moving the image in a first direction; and performing a preliminary scanning again based on the read image obtained in the first preliminary scanning step. If it is determined whether or not to execute the preliminary scan, and if the preliminary scan is to be performed again, the image pickup unit is moved while relatively moving the document image relative to the image pickup unit in a second direction opposite to the first direction. A second pre-scanning step of pre-scanning the original image by the following method. 10. An image reading method in which a document image is preliminarily scanned, a reading condition for a main scan is determined based on the result, and a main scan is executed in accordance with the reading condition. A preliminary scanning step of performing a preliminary scanning, a determining step of determining whether or not the preliminary scanning by the preliminary scanning step has been performed under appropriate reading conditions; and when it is determined that the preliminary scanning has not been performed under the appropriate reading conditions, A control step of re-executing the preliminary scanning step. 11. A memory medium storing a control program for preliminarily scanning a document image, determining a main scanning reading condition based on a result of the preliminary scanning, and executing a main scanning according to the scanning condition. The control program is obtained by a first preliminary scanning step of preliminarily scanning the original image by the imaging unit while relatively moving the original image in the first direction with respect to the imaging unit; and the first preliminary scanning step. Based on the read image, it is determined whether or not to execute the preliminary scan again. If the preliminary scan is to be performed again, the original image is transmitted to the imaging unit in a direction opposite to the first direction. A second pre-scanning step of pre-scanning the document image by the imaging unit while relatively moving in two directions. 12. A memory medium storing a control program for preliminarily scanning a document image, determining a reading condition at the time of a main scan based on a result of the preliminary scanning, and executing a main scan according to the reading condition. The control program includes: a pre-scanning step of pre-scanning a document image by an imaging unit; a determining step of determining whether or not the pre-scanning in the pre-scanning step has been performed under appropriate reading conditions; A control step of re-executing the pre-scanning step when it is determined that the pre-scanning has not been performed.