JP2001223847A - Method and device for exposure control of film scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for exposure control of a film scanner which use as small number of analog amplifiers as possible to prevent the degradation of S/N and improve the precision of digital gradation conversion. SOLUTION: The base area of a film is read before the film is read, and a CCD electronic shutter numerical aperture and an analog amplifier gain are adjusted to set an analog system set value so that an RGB digital output signal value of the read base area may be outputted with a maximum value. Therefore, the analog amplifier gain is suppressed to about one-fold to improve S-N, and the precision of digital gradation conversion such as white-black balance and gamma adjustment is improved, and increase of gradation by a negative base is allowed for.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure control apparatus and an exposure control method for a film scanner, and more particularly to a film scanner for performing an initial setting operation of analog set values before reading a film on which image information is recorded. The present invention relates to an exposure control device and an exposure control method.

[0002]

2. Description of the Related Art Conventionally, in an exposure control device of a film scanner, a base area which is an unexposed portion of a film on which image information is recorded is read, and respective voltages of RGB signals inputted to an A / D converter are converted into analog signals. There has been proposed an exposure control method for a film scanner which controls an amplifier gain to a predetermined value.

[0003]

However, the analog amplifier gain is controlled to control the R input to the A / D converter.
In the method of adjusting the voltage of each of the GB signals to a predetermined value,
In addition to the image signal component, a noise component is also amplified at the same time.
/ N is worsened.

SUMMARY OF THE INVENTION The present invention provides an exposure control apparatus for a film scanner and an exposure control method for the same which can prevent the deterioration of S / N and improve the accuracy of digital gradation conversion processing without using an analog amplifier. The purpose is to:

[0005]

In order to achieve the above object, an exposure control device for a film scanner according to the present invention comprises a scanning device for scanning a film on which image information is recorded, and an illumination device for illuminating the film. An exposure means for reading the image information at an arbitrary aperture ratio, and an exposure control means for amplifying the read image information to perform exposure control, wherein the exposure control means Adjusts at least one of the scanning speed of the scanning unit, the light amount of the illumination unit, and the aperture ratio based on the output value obtained by reading the base area of the film, thereby reducing the amplification factor to approximately 1 and exposing the exposure unit. The control is performed.

According to a second aspect of the present invention, in the exposure control apparatus for a film scanner according to the first aspect, the exposure control means adjusts the aperture ratio preferentially.

According to a third aspect of the present invention, in the exposure control apparatus for a film scanner according to the second aspect, the exposure control means adjusts the light amount preferentially.

According to a fourth aspect of the present invention, in the exposure control apparatus for a film scanner according to the second or third aspect, the exposure control means adjusts the scanning speed preferentially. I do.

According to a fifth aspect of the present invention, there is provided a film scanner exposure control apparatus according to any one of the first to fourth aspects, wherein the output value is R.
It is characterized by comprising a voltage value of a GB signal.

According to another aspect of the present invention, there is provided an exposure control method for a film scanner, comprising: a scanning step of scanning a film on which image information is recorded; an illumination step of illuminating the film; Is read at an arbitrary aperture ratio, an exposure control method of an exposure control device of a film scanner including an exposure control step of performing exposure control by amplifying the read image information, wherein the exposure control step,
The scanning speed of the scanning step based on the output value of reading the base area of the film, the light amount of the illumination step,
The exposure control is performed by controlling at least one of the aperture ratios to suppress the amplification factor to approximately one.

According to a seventh aspect of the present invention, in the exposure control method of the film scanner according to the sixth aspect, the exposure control step adjusts the aperture ratio preferentially.

An exposure control method for a film scanner according to an eighth aspect of the present invention is the exposure control method for a film scanner according to the seventh aspect, wherein the exposure control step adjusts the light amount preferentially.

According to a ninth aspect of the present invention, in the exposure control method of the film scanner according to the seventh or eighth aspect, the exposure control step preferentially adjusts the scanning speed. I do.

According to a tenth aspect of the present invention, there is provided the film scanner exposure control method according to any one of the sixth to ninth aspects, wherein the output value is:
It is characterized by comprising a voltage value of an RGB signal.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) The configuration of an exposure control device for a film scanner according to a first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a block diagram showing a schematic configuration of an exposure control device of a film scanner according to a first embodiment of the present invention.

Reference numeral 101 denotes a lamp for illuminating a negative film (hereinafter, referred to as “film”) as a transparent original.
The lighting is controlled by a lamp driving circuit 108 which is connected to the lamp driving circuit 108 and receives a command from the CPU 112. Reference numeral 102 denotes a film folder for holding a film, and a sub-scanning motor 105 using a stepping motor.
Can move in the direction of arrow A in FIG.
The driving is controlled by the motor driving circuit 107 which receives the instruction. Reference numeral 103 denotes a CCD line sensor (hereinafter, referred to as “CC”)
D ") 104.
The CCD 104 has an electronic shutter function that is controlled by a CCD driving circuit 106 that receives a command from the CPU 112 and that controls the timing of discharging the accumulated charge. CCD1
Reference numeral 04 is attached so as to be perpendicular to the direction of arrow A in the drawing, which is the direction of movement of the film folder 102,
The main scanning direction, which is the longitudinal direction of the CCD 104, and the sub-scanning direction, which is the moving direction of the film folder 102, are arranged so as to have a right angle (perpendicular).

Reference numeral 109 denotes an analog image processing circuit which performs gain setting, clamp processing, and the like of the analog image signal output from the CCD 104, and can independently amplify each of the RGB signals by an internal analog amplifier. An A / D converter 110 is connected to the analog image processing circuit 109 and converts an analog image signal output from the analog image processing circuit 109 into a digital signal. Reference numeral 111 denotes an image processing unit that processes a digital image signal digitized by the A / D converter 110, a histogram creation unit (not shown) that creates a histogram from the digital image signal, and a negative / positive conversion of the image signal.
A gradation conversion curve creation unit (not shown) that creates a gradation conversion curve for adjusting the white balance to obtain an appropriate gradation.
Etc. The CPU 112 controls the analog image processing circuit 1
09, a system controller that is connected to the image processing unit 111 and the like, stores the entire sequence of the film scanner, and executes various operations in accordance with instructions from an external device (not shown) such as a personal computer. Reference numeral 113 denotes a line buffer for temporarily storing image data. Reference numeral 114 denotes an interface unit (hereinafter, “I / F”) for connection to an external device.
It is). The sub-scanning position detection sensor 115 is composed of a photo interrupter, is arranged in the film folder 102, and detects an initial scanning position by scanning the projection shape or the like.

In such a configuration, software in the CPU 112 (hereinafter referred to as “firmware”)
Image data is output to an external device through mutual communication with software (hereinafter referred to as “driver software”) for operating the film scanner from the external device.

Next, an initial setting operation of an analog set value in the exposure control device of the film scanner shown in FIG. 1 will be described with reference to FIGS. FIG. 2 is a flowchart showing an initial setting operation process of an analog set value in the exposure control device of the film scanner of FIG. In the present embodiment, the initial setting operation of the analog set value refers to the RGB values obtained by reading the base region of the film.
A CCD electronic shutter aperture ratio (hereinafter, referred to as “opening ratio”) and an analog amplifier gain (hereinafter, referred to as “gain”), which are analog system setting values, are determined based on the digital signal output value. Between ~ 100%
The gain is made variable between 0.4 and 2.0.

In FIG. 2, the power of the film scanner is turned on, the lamp 101 is turned on, and after the lamp light quantity is stabilized, for example, the aperture ratio is set to 50% for both RGB and the gain is set to 1.0 for both RGB. Initial value of each analog system set value at power-on is set (step S20)
1). Subsequently, shading correction is performed without inserting a film into the film folder 102 (step S).
202).

The lamp 1 is subjected to shading correction processing performed before the initial setting operation of the analog system set value.
01, the lens 103, and the CCD 104 are corrected for positional unevenness, sensitivity variation for each pixel, and the like, and each analog system set value is, for example, an aperture ratio R: 30%, G: 4
The correction is made so that 0%, B: 50%, and gain RGB are both 1.0 times. In addition, by this shading correction process, the lamp 101 is turned on in a state where the film is not inserted, and the RGB values obtained when the image data of the film is read.
Since the digital signal output value of each color is set to be output at substantially the maximum value (255 in this embodiment), the digital output signal does not saturate even if the thin base region is read.

Next, the film is transferred to the film folder 102.
Then, the base area of the film is read based on the analog set values corrected by the shading correction processing (step S203). Subsequently, the values are set by adjusting the aperture ratio and the gain in this order so that the digital output signal values of the respective RGB colors are output at the maximum value (255) when the base area is read (step S204). , S205), the image information of the film is read (step S206), and this processing ends. According to the process of FIG. 2, it is possible to set an analog set value from which the base region of the film is removed before reading the film on which the image information is recorded.

FIG. 3 shows steps S203 to S20 in FIG.
6 is a flowchart illustrating details of a change process of an analog set value in FIG. Steps S301 to S30 in FIG.
3 corresponds to steps S203 to S205 in FIG.

In step S301, the film is loaded.
The lamp 1 is inserted into a predetermined position of the
01 is turned on, and each analog after shading correction described above is turned on.
The base area is read using the log system setting value. Next, read
The RGB digital signal output values (D
R₀, DG₀, DB₀) Is output at the maximum value (255)
Thus, each of the RGB digital signals after shading correction
Output value aperture ratio (CR ₀, CG₀, CB₀) Based on
The aperture ratio (CR, CG, CB) is calculated by the formula, and the aperture ratio is calculated.
Is adjusted (step S302).

CR = CR ₀ × 255 / DR ₀ CG = CG ₀ × 255 / DG ₀ CB = CB ₀ × 255 / DB ₀ For example, DR ₀ = 100, DG ₀ = 150, DB ₀ = 20
0, CR ₀ = 30, CG ₀ = 40, and CB ₀ = 50 are substituted. CR = 30 × 255/100 = 76.5 CG = 40 × 255/150 = 68.0 CB = 50 × 255 /200=63.75.

Finally, each RGB after shading correction
Digital signal output value gain (AR ₀, AG₀, AB₀)
From the RGB digital signal output of the read base area
Value (DR₀, DG₀, DB₀) Is output at the maximum value (255)
The gain (AR, AG, AB) is calculated by the following equation
To adjust the gain and adjust the initial
The period setting operation ends (step S303).

AR = AR ₀ × 255 / (DR ₀ × (CR / CR ₀ )) AG = AG ₀ × 255 / (DG ₀ × (CG / CG ₀ )) AB = AB ₀ × 255 / (DB ₀ × (CB / CB ₀ )) By substituting the above values, AR = 1.0 × 255 / (100 × (76.5 / 3)
0)) = 1.0 AG = 1.0 × 255 / (150 × (68.0 / 4)
0)) = 1.0 AB = 1.0 × 255 / (200 × (63.75 / 5)
0)) = 1.0, and the value of the base area of the film can be canceled based on the aperture ratio of the CCD electronic shutter, so that the value of the analog amplifier gain can be suppressed to approximately one time.

In this embodiment, when the base area of the film is read and each analog system set value is determined, the RGB digital output signal of the base area is referred to. The voltage value of the RGB signal may be set to a predetermined value. Further, when reading the base area of the film, the base film may be inserted into a predetermined position. May be read.

As described above, the base area of the film is read, the initial setting of each analog system setting value is performed, and after the film on which the image information is recorded is inserted, the pre-scan for reading at a coarse resolution is performed to obtain the RGB digital image information. RG
The B signal output value is obtained. R thus obtained
A histogram is created for each of the RGB colors from the GB digital image information, and based on the maximum and minimum values of the histogram, white-black balance adjustment of image information and gamma adjustment based on Evans's theorem are performed. Perform main scan with each analog system set value and gradation conversion curve set by pre-scan, read image signal at desired resolution,
After performing various processes, the data is output to an external device via the I / F 114.

According to the first embodiment, before reading a film, the base area of the film is read (steps S203 and S301), and the RG of the read base area is read.
The CCD electronic shutter aperture ratio (C) is set so that the B digital output signal values (DR ₀ , DG ₀ , DB ₀ ) are output at the maximum value.
R, CG, CB), analog amplifier gain (AR, A
G, AB) to set the analog set value, so that the analog amplifier gain can be suppressed to approximately 1 to improve the S / N, and furthermore, such as white / black balance, gamma adjustment, etc. By improving the accuracy of the gradation conversion processing, it is possible to expect an increase in gradation for the negative base.

(Second Embodiment) Hereinafter, a second embodiment of the present invention will be described.
An exposure control device for a film scanner according to the embodiment will be described. The second embodiment is basically the same in configuration as the first embodiment, except that the lamp driving circuit 108 in FIG. 1 has a light amount adjusting function for adjusting the light amount of the lamp 101. different.

FIG. 4 is a flowchart showing an initial setting operation process of an analog set value in the exposure control device of the film scanner according to the second embodiment of the present invention.
In the present embodiment, the initial setting operation of the analog set value refers to an R value obtained by reading the base region of the film.
Based on the GB digital signal output value, the lamp light amount (hereinafter, referred to as “light amount”), the CCD electronic shutter aperture ratio (hereinafter, referred to as “opening ratio”), and the analog amplifier gain (hereinafter, referred to as “gain”) are analog system set values. And determining the light amount between 50% and 100%, the aperture ratio between 0% and 100%, and the gain between 0.4 and 2.0 times. I have.

In FIG. 4, after the power of the film scanner is turned on and the lamp 101 is turned on and the lamp light quantity is stabilized, for example, the light quantity is 50% and the aperture ratio is 5 for RGB.
Initial values of the respective analog system set values at the time of power-on are set so that 0% and the gain are 1.0 times for both RGB (step S401). Subsequently, shading correction is performed without inserting a film into the film folder 102 (step S402).

The lamp 1 is subjected to shading correction processing performed at a stage prior to the initial setting operation of the analog set value.
01, the lens 103, and the CCD 104 are corrected for positional unevenness, sensitivity variation for each pixel, and the like, and each analog system set value is, for example, 60% light intensity and an aperture ratio R: 4.
0%, G: 50%, B: 60%, and gain RGB are all 1.0 times. In addition, by this shading correction processing, the digital signal output value of each color of RGB when the image data of the film is read by turning on the lamp 101 in a state where the film is not inserted is output as a substantially maximum value (255 in the present embodiment). Therefore, no matter how thin the base area is read, the digital signal output value does not saturate.

Next, the film is transferred to the film folder 102.
The base area of the film is read based on each analog system set value corrected by the shading correction processing (step S403). Subsequently, adjustment is performed in the order of the light amount, the aperture ratio, and the gain so that the digital signal output value of each color of RGB is output at the maximum value (255) when the base area is read, and the respective values are set ( (Steps S404 to S406), the image information of the film is read (step S407), and this processing ends. According to the processing of FIG. 4, it is possible to set the analog system set value in which the base area of the film is removed before reading the film on which the image information is recorded.

FIG. 5 shows steps S403 to S40 in FIG.
6 is a flowchart illustrating details of a change process of an analog set value in 6. Steps S501 and S50 in FIG.
Steps 2 to S503, S504, and S505 correspond to steps S403 to S406 in FIG. 4, respectively.

In step S501, a film is inserted into a predetermined position of the film
01 is turned on, and the base area is read using each analog set value after the shading correction described above. Next, the RGB digital signal output values (D
R ₀ , DG ₀ , DB ₀ ) (hereinafter, “DMIN”)
Is obtained (step S502). For example, DR
_{When 0} = 100, DG ₀ = 150 and DB ₀ = 200, D
MIN = 100.

Next, the obtained DMIN is the maximum value (255).
The light amount (L) is calculated based on the light amount (L ₀ ) after the shading correction by the following equation, and the light amount is adjusted (step S503).

L = L ₀ × (255 / DMIN) Assuming that the light amount L ₀ after shading correction is 60%, L = 60 × (255/100) = 153. If the light amount L exceeds 100% by adjusting the light amount L ₀ and DMIN does not reach 255, the light amount L is set to 1
Set to 00%.

Next, the read RGB digital signal output values (DR ₀ , DG ₀ , DB ₀ ) of the base area are read to the maximum value (2
55), the aperture ratios (CR ₀ , CG ₀ , C ₀ ) of the RGB digital signal output values after shading correction are output.
B ₀ ) and the aperture ratio (CR, CG, C
B) is set, and the balance of each of RGB is adjusted (step S504).

CR = CR ₀ × 255 / (DR ₀ × (L / L ₀ )) CG = CG ₀ × 255 / (DG ₀ × (L / L ₀ )) CB = CB ₀ × 255 / (DB ₀ × (L / L ₀ )) For example, the above DR ₀ = 100, DG ₀ = 150, DB ₀ =
Substituting the values of 200, CR ₀ = 40, CG ₀ = 50, and CB ₀ = 60, CR = 40 × 255 / (100 × (100/60)) =
61.2 CG = 50 × 255 / (150 × (100/60)) =
51.0 CB = 60 × 255 / (200 × (100/60)) =
45.9.

Finally, each RGB after shading correction
Digital signal output value gain (AR ₀, AG₀, AB₀)
From the RGB digital signal output of the read base area
Value (DR₀, DG₀, DB₀) Is output at the maximum value (255)
So that the gain (AR, AG, AB) is
Set and adjust the gain to set the initial
The setting operation ends (step S505).

AR = AR ₀ × 255 / (DR ₀ × (L / L
₀ ) × (CR / GR ₀ ) AG = AG ₀ × 255 / (DG ₀ × (L / L ₀ ) × (CG
/ CG ₀ ) AB = AB ₀ × 255 / (DB ₀ × (L / L ₀ ) × (CB
/ CB ₀ ) By substituting the above values, AR = 1.0 × 255 / (100 × (100/60) ×
(61.2 / 40)) = 1.0 AG = 1.0 × 255 / (150 × (100/60) ×
(51.0 / 50)) = 1.0 AB = 1.0 × 255 / (200 × (100/60) ×
(45.9 / 60)) = 1.0 In this case, since the value of the base area of the film could be canceled based on the light intensity of the lamp and the aperture ratio of the CCD electronic shutter, the value of the analog amplifier gain was almost doubled. Can be suppressed.

In this embodiment, the RGB digital output signal of the base area is referred to when the base area of the film is read and each analog set value is determined, but is input to the A / D converter 110. The voltage value of the RGB signal may be set to a predetermined value. Further, when reading the base area of the film, the base film may be inserted into a predetermined position. May be read.

As described above, the base area of the film is read, the respective analog system setting values are initialized, and after the film on which the image information is recorded is inserted, the pre-scan for reading at a coarse resolution is performed to obtain the RGB digital image information. RG
The B signal output value is obtained. R thus obtained
A histogram is created for each of the RGB colors from the GB digital image information, and based on the maximum and minimum values of the histogram, white-black balance adjustment of image information and gamma adjustment based on Evans's theorem are performed. The main scan is performed using each analog system set value and gradation conversion curve set by the prescan, the image signal is read at a desired resolution, and various processes are performed, and then output to an external device via the I / F 114.

According to the second embodiment, before reading a film, the base area of the film is read (steps S403 and S501), and each R of the read base area is read.
The minimum value (DMIN) of the GB digital output signal values is determined (step S502), and the minimum value is the maximum value (255).
Is adjusted (step S503), and the read RGB digital signal output values (DR ₀ , DG ₀ , DB ₀ ) of the base area are output at the maximum value (255). The CCD electronic shutter aperture ratio (CR, CG, CB) and analog amplifier gain (A
R, AG, and AB) are adjusted to set the analog set values.
N can be improved, and furthermore, the precision of digital gradation conversion processing such as white / black balance and gamma adjustment can be improved, and an increase in gradation for a negative base can be expected.

(Third Embodiment) Hereinafter, a third embodiment of the present invention will be described.
An exposure control device for a film scanner according to the embodiment will be described. The third embodiment is basically the same as the first embodiment, except that the motor drive circuit 107 in FIG. 1 has a function of adjusting the moving speed of the film folder 102 by the sub-scanning motor 105. It differs in that it is prepared.

FIG. 6 is a flow chart showing an initial setting operation process of an analog set value in the exposure control device of the film scanner according to the third embodiment of the present invention.
In the present embodiment, the initial setting operation of the analog set value refers to an R value obtained by reading the base region of the film.
Based on the GB digital signal output value, a CCD electronic shutter aperture ratio (hereinafter, referred to as "opening ratio"), an analog amplifier gain (hereinafter, referred to as "gain"), which is an analog system setting value, and scanning (scanning), which is an image reading speed.
Speed is determined, and the aperture ratio is set to 0% to 10%.
When the gain is between 0.4 and 2.0 times, the scan speed is 1 ×, 1/2 ×, 1/3 ×,
It is variable at either 1/4 or 1/6 speed.

In FIG. 6, after the power of the film scanner is turned on and the lamp 101 is turned on and the lamp light quantity is stabilized, for example, the aperture ratio is 50% for RGB, the gain is 1.0 times for RGB, and the scan speed is increased. An initial value of each analog system set value at the time of power-on is set such as 1 × speed (step S601). Subsequently, shading correction is performed without inserting the film into the film folder 102 (step S602).

The lamp 1 is subjected to shading correction processing performed before the initial setting operation of the analog system set value.
01, the lens 103, and the CCD 104 are corrected for positional unevenness, sensitivity variation for each pixel, and the like, and each analog system set value is, for example, an aperture ratio R: 40%, G: 5
0%, B: 60%, gain RGB are both 1.0 times, and the scan speed is corrected to 1/2 times speed. By this shading correction process, the digital signal output value of each of the RGB colors when the lamp 101 is turned on and the image data of the film is read in a state where the film is not inserted is approximately the maximum value (255 in this embodiment). Since the output is set to be output, the digital signal output value does not saturate even if the thin base region is read.

Next, the film is transferred to the film folder 102.
Then, the base area of the film is read based on the analog set values corrected by the shading correction processing (step S603). Subsequently, the scanning speed, the aperture ratio, and the gain are adjusted in this order so that the digital signal output values of each of the RGB colors are output at the maximum value (255) when the base area is read, and the respective values are set. (Steps S604 to S60
6) The image information of the film is read (step S6).
07), this process ends. According to the processing of FIG. 6, it is possible to set an analog set value in which the base region of the film is removed before reading the film on which the image information is recorded.

FIG. 7 shows steps S603 to S60 in FIG.
6 is a flowchart illustrating details of a change process of an analog set value in 6. Steps S701 and S70 in FIG.
Steps 2 to S704, S705, and S706 correspond to steps S603 to S606 in FIG. 6, respectively.

In step S701, a film is inserted into a predetermined position of the film
01 is turned on, and the base area is read using each analog set value after the shading correction described above. Next, the RGB digital signal output values (D
R ₀ , DG ₀ , DB ₀ ) (hereinafter, “DMIN”)
(Step S702). For example, DR
_{When 0} = 100, DG ₀ = 150 and DB ₀ = 200, D
MIN = 100.

Next, the obtained DMIN is compared with a preset threshold value X. When DMIN is equal to or less than the threshold value (YES in step S703), the scan speed S is changed from the scan speed S ₀ after the shading correction to 1 A step low speed is set (step S704). In this process,
For example, if X = 128, DMIN is equal to or less than X, and the scan speed S ₀ after shading correction is 1
Since the speed was 1/2 speed, S is changed to 1/4 speed. On the other hand, if the DMIN exceeds the threshold as a result of the comparison in step S703 (NO in step S703), the process proceeds to step S703.
Proceed to 705.

Next, the read RGB digital signal output values (DR ₀ , DG ₀ , DB ₀ ) of the base area are read to the maximum value (2
55), the aperture ratios (CR ₀ , CG ₀ , C ₀ ) of the RGB digital signal output values after shading correction are output.
B ₀ ) and the aperture ratio (CR, CG, C
B) is set, and the balance of each of RGB is adjusted (step S705).

CR = CR ₀ × 255 / (DR ₀ × (S ₀ / S)) CG = CG ₀ × 255 / (DG ₀ × (S ₀ / S)) CB = CB ₀ × 255 / (DB ₀ × (S ₀ / S)) The above DR ₀ = 100, DG ₀ = 150, DB ₀ = 200,
By substituting the respective values of CR ₀ = 40, CG ₀ = 50 and CB ₀ = 60, CR = 40 × 255 / (100 × ((1/2) / (1 /
4)) = 51.0 CG = 50 × 255 / (150 × ((1/2) / (1 /
4)) = 42.5 CB = 60 × 255 / (200 × ((1/2) / (1 /
4)) = 38.25.

Finally, each RGB after shading correction
Digital signal output value gain (AR ₀, AG₀, AB₀)
From the RGB digital signal output of the read base area
Value (DR₀, DG₀, DB₀) Is output at the maximum value (255)
The gain (AR, AG, AB) is calculated by the following equation
To adjust the gain and adjust the initial
The period setting operation ends (step S706).

AR = AR ₀ × 255 / (DR ₀ × (S ₀ /
S) × (CR / CR ₀ )) AG = AG ₀ × 255 / (DG ₀ × (S ₀ / S) × (CG
/ CG ₀ )) AB = AB ₀ × 255 / (DB ₀ × (S ₀ / S) × (CB
/ CB ₀ )) By substituting the above values, AR = 1.0 × 255 / (100 × ((1/2) / (1/4)) × (5
1.0 / 40)) = 1.0 AG = 1.0 × 255 / (150 × ((1/2) / (1/4)) × (4
2.5 / 50)) = 1.0 AB = 1.0 × 255 / (200 × ((1/2) / (1/4)) × (3
8.25 / 60)) = 1.0 In this case, since the value of the base area of the film could be canceled based on the scan speed and the aperture ratio of the CCD electronic shutter, the value of the analog amplifier gain could be suppressed to almost one time. it can.

In this embodiment, the adjustment of the scan speed is given the highest priority. However, the setting of the scan speed is not changed in step S704, and the process proceeds to step S70.
5, the load on the CCD electronic shutter may be increased. In reading the base area of the film and determining each analog system set value, the RGB digital output signal of the base area is referred to. However, the voltage value of the RGB signal input to the A / D converter 110 is determined by a predetermined value. May be set to a value.
Further, when reading the base area of the film, the base film may be inserted into a predetermined position. May be read.

In this manner, the base area of the film is read, and the initial values of the respective analog set values are set.
After the insertion of the film on which the image information is recorded, prescanning is performed at a coarse resolution to obtain RGB signal output values of RGB digital image information. From the RGB digital image information thus obtained, a histogram is created for each of the RGB colors, and the white and black balance of the image information is adjusted based on the maximum and minimum values of the histogram.
And gamma adjustment based on Evans' theorem. The main scan is performed using each analog system set value and gradation conversion curve set by the prescan, the image signal is read at a desired resolution, and various processes are performed, and then output to an external device via the I / F 114.

According to the third embodiment, before reading a film, the base region of the film is read (steps S603 and S701), and each R of the read base region is read.
The minimum value (DMIN) of the GB digital output signal values is obtained (step S702). When the minimum value is equal to or smaller than the threshold value X (YES in step S703), the scan speed (S) is changed to the scan speed after shading correction (S
₀ ), the speed is set lower by one step (step S704), and furthermore, the CCD electronic device outputs the RGB digital signal output values (DR ₀ , DG ₀ , DB ₀ ) of the read base area at the maximum value (255). Shutter aperture ratio (CR, CG, C
B) Since the analog system set values are set by adjusting the analog amplifier gains (AR, AG, AB), the analog amplifier gain can be suppressed to approximately one and the S / N can be improved. By improving the precision of digital gradation conversion processing such as white-black balance and gamma adjustment, it is possible to expect an increase in gradation for a negative base.

(Fourth Embodiment) Hereinafter, a fourth embodiment of the present invention will be described.
An exposure control device for a film scanner according to the embodiment will be described. The fourth embodiment has basically the same configuration as that of the first embodiment, except that the lamp driving circuit 108 in FIG. 1 has a light amount adjusting function for adjusting the light amount of the lamp 101. The difference is that one motor drive circuit 107 has a function of adjusting the moving speed of the film folder 102 by the sub-scanning motor 105.

FIG. 8 is a flowchart showing an initial setting operation process of an analog set value in the exposure control device of the film scanner according to the fourth embodiment of the present invention.
In the present embodiment, the initial setting operation of the analog set value refers to an R value obtained by reading the base region of the film.
Based on the GB digital signal output value, a lamp light amount (hereinafter, referred to as “light amount”), a CCD electronic shutter aperture ratio (hereinafter, “opening ratio”), an analog amplifier gain (hereinafter, “gain”), which are analog system set values, and It is to determine a scanning speed which is an image reading speed. The light amount is set between 50% and 100%, the aperture ratio is set between 0% and 100%, and the gain is set at 0.4 times. When the scan speed is 1 × speed, 1/2 × speed, 1 ×
The speed is variable at any one of / 3 times speed, 1/4 times speed, and 1/6 times speed.

In FIG. 8, after the power of the film scanner is turned on and the lamp 101 is turned on and the lamp light quantity is stabilized, for example, the light quantity is set to 50% and the aperture ratio is set to 5 for both RGB.
The initial value of each analog set value at power-on is set so that 0%, the scan speed is 1 ×, and the gain is 1.0 × for both RGB (step S801). Subsequently, shading correction is performed without inserting the film into the film folder 102 (step S802).

The lamp 1 is subjected to shading correction processing which is performed before the initial setting operation of the analog system set value.
01, the lens 103, and the CCD 104 are corrected for positional unevenness, sensitivity variation for each pixel, and the like, and each analog system set value is, for example, 60% light intensity and an aperture ratio R: 4.
0%, G: 50%, B: 60%, scan speed 1 /
The double speed and the gain RGB are both corrected to be 1.0 times. Further, by this shading correction processing, the digital signal output value of each of the RGB colors when the lamp 101 is turned on and the image data of the film is read in a state where the film is not inserted is approximately the maximum value (25 in this embodiment).
Since the setting is made so as to output in 5), no matter how thin the base area is read, the digital signal output value does not saturate.

Next, the film is transferred to the film folder 102.
Then, the base area of the film is read based on each analog set value corrected by the shading correction processing (step S803). Subsequently, adjustment is made in the order of light quantity, scan speed, aperture ratio, and gain so that the output signal value of each color of RGB is output at the maximum value (255) when the base area is read, and the respective values are set. (Steps S804 to S807),
The image information of the film is read (step S60).
7), end this processing. According to the processing of FIG. 8, it is possible to set the analog set value in which the base region of the film is removed before reading the film on which the image information is recorded.

FIG. 9 shows steps S803 to S80 in FIG.
7 is a flowchart illustrating details of a change process of an analog set value in FIG. 7. Steps S901 and S90 in FIG.
2 to S903, S904 to S906, S907, S90
8 corresponds to steps S803 to S807 in FIG.

In step S901, a film is inserted into a predetermined position of the film
01 is turned on, and the base area is read using each analog set value after the shading correction described above. Next, the RGB digital signal output values (D
R ₀ , DG ₀ , DB ₀ ) (hereinafter, “DMIN”)
Is obtained (step S902). For example, DR
_{When 0} = 100, DG ₀ = 150 and DB ₀ = 200, D
MIN = 100.

Next, the obtained DMIN is the maximum value (255).
The light amount (L) is calculated based on the light amount (L ₀ ) after the shading correction by the following formula, and the light amount is adjusted (step S903).

L = L ₀ × (255 / DMIN) Assuming that the light amount L ₀ after shading correction is 60%, L = 60 × (255/100) = 153.

Next, in step S904, the light amount L
By adjusting ₀ , it is determined whether the light amount L is 100% or more,
If the light amount L exceeds 100% due to the adjustment of the light amount L ₀ and DMIN does not reach 255 (step S
YES at 904), the light amount L is set to 100%, to set the scanning speed S from S ₀ after the shading correction to one step a low speed (step S905). In this process, the scan speed S ₀ after shading correction is 1
The scan speed S is changed to ４ × speed since the speed was ２ × speed. On the other hand, as a result of the determination in step S904,
If DMIN has reached the 255 by adjusting the amount of light (NO in step S904), without changing the scanning speed S, and S = S ₀ (step S906).

Next, the read RGB digital signal output values (DR ₀ , DG ₀ , DB ₀ ) of the base area are read to the maximum value (2
55), the aperture ratios (CR ₀ , CG ₀ , C ₀ ) of the RGB digital signal output values after shading correction are output.
B ₀ ) and the aperture ratio (CR, CG, C
B) is set, and the balance of each of RGB is adjusted (step S907).

CR = CR ₀ × 255 / (DR ₀ × (L / L
₀ ) × (S ₀ / S)) CG = CG ₀ × 255 / (DG ₀ × (L / L ₀ ) × (S ₀ /
S)) CB = CB ₀ × 255 / (DB ₀ × (L / L ₀ ) × (S ₀ /
S)) The above DR ₀ = 100, DG ₀ = 150, DB ₀ = 200,
By substituting the values of CR ₀ = 40, CG ₀ = 50, and CB ₀ = 60, CR = 40 × 255 / (100 × (100/60) × ((1/2) / (1
/4))=30.6≒31 CG = 50 × 255 / (150 × (100/60) × ((1/2) / (1
/4))=25.5≒26 CB = 60 × 255 / (200 × (100/60) × ((1/2) / (1
/4))=22.95≒23.

Finally, each RGB after shading correction
Digital signal output value gain (AR ₀, AG₀, AB₀)
From the RGB digital signal output of the read base area
Value (DR₀, DG₀, DB₀) Is output at the maximum value (255)
The gain (AR, AG, AB) is calculated by the following equation
To adjust the gain and adjust the initial
The period setting operation ends (step S908).

AR = AR ₀ × 255 / (DR ₀ × (L / L ₀ ) × (S ₀ / S) × (CR / CR ₀ )) AG = AG ₀ × 255 / (DG ₀ × (L / L ₀ ) × (S ₀ / S) × (CG / CG ₀ )) AB = AB ₀ × 255 / (DB ₀ × (L / L ₀ ) × (S ₀ / S) × (CB / CB ₀ )) AR = 1.0 × 255 / (100 × (100/60) × ((1/2) / (1/4)) × (31/40)) = 0.987 ≒ 1.0 AG = 1.0 × 255 / (150 × (100/60) × ((1/2) / (1/4)) × (26/50)) = 0.981 ≒ 1.0 AB = 1.0 × 255 / ( 200 x (100/60) x ((1/2) / (1/4)) x (23/60)) = 0.998 / 1.0 In this case, the lamp light amount, scan speed, and C
Since the value in the base region of the film could be canceled based on the aperture ratio of the CD electronic shutter, the value of the analog amplifier gain can be suppressed to almost one time.

In the present embodiment, step S30
Even if the lamp light amount L exceeds 100% in step 4, the scan speed is not changed in step S905 in order to give top priority to the scan speed, and the load on the CCD electronic shutter in step S907 is increased. Good. In reading the base region of the film and determining each analog set value, the RGB digital output signal of the base region was referred to.
The voltage value of the RGB signal input to 10 may be set to a predetermined value. Further, when reading the base area of the film, the base film may be inserted into a predetermined position. May be read.

In this way, the base area of the film is read, and the initial values of the analog set values are set.
After the insertion of the film on which the image information is recorded, prescanning is performed at a coarse resolution to obtain RGB signal output values of RGB digital image information. From the RGB digital image information thus obtained, a histogram is created for each of the RGB colors, and the white and black balance of the image information is adjusted based on the maximum and minimum values of the histogram.
And gamma adjustment based on Evans' theorem. The main scan is performed using each analog system set value and gradation conversion curve set by the prescan, the image signal is read at a desired resolution, and various processes are performed, and then output to an external device via the I / F 114.

According to the fourth embodiment, before reading a film, the base area of the film is read (steps S803, S901), and each R of the read base area is read.
The minimum value (DMIN) of the GB digital output signal values is obtained (step S902), and the minimum value is the maximum value (255).
In adjusting the lamp light intensity (L) to be output (step S903), the light amount L is 100% by adjusting the amount of light L ₀
It exceeds the, if DMIN does not reach the 255 set (YES at step S904), the scan speed S from S ₀ after the shading correction to one step a low speed (step S905), further, RGB base region read The CCD electronic shutter aperture ratio (CR, CG, CB) and analog amplifier gain (AR, AG, AB) are set so that the digital signal output values (DR ₀ , DG ₀ , DB ₀ ) are output at the maximum value (255). Since the analog system set value is set by adjusting, the analog amplifier gain can be suppressed to approximately 1 to improve the S / N, and further, the digital gradation conversion processing such as white / black balance and gamma adjustment can be performed. The accuracy can be improved, and an increase in the gradation for the negative base can be expected.

[0079]

As described in detail above, according to the apparatus of the first aspect and the method of the sixth aspect, the scanning speed is determined based on the output value obtained by reading the base area of the film before reading the image information. , Light intensity, and aperture ratio
Since the exposure control is performed with the amplification factor suppressed to approximately 1 by adjusting the two, it is possible to prevent the deterioration of S / N,
The accuracy of gradation conversion processing such as white-black balance adjustment and gamma adjustment can be improved.

According to the apparatus according to the second aspect and the method according to the seventh aspect, the aperture ratio is preferentially adjusted.
The effects of the above-described apparatus and the method of the fifth aspect can be reliably achieved.

According to the apparatus according to the third aspect and the method according to the eighth aspect, the light amount is preferentially adjusted in addition to the aperture ratio, so that the effects of the apparatus according to the first aspect and the method according to the fifth aspect are reduced. It can be played more reliably.

According to the apparatus according to the fourth aspect and the method according to the ninth aspect, the scanning speed is preferentially adjusted in addition to the aperture ratio and the light amount.
The effects of the described method can be achieved more reliably.

According to the apparatus of the fifth aspect and the method of the tenth aspect, the output value obtained by reading the image information is RGB.
Since the exposure control is performed with the amplification factor suppressed to approximately one by using the voltage value of the signal, the effects of the device according to the first aspect and the method according to the fifth aspect can be more reliably achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an exposure control device of a film scanner according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an initial setting operation process of an analog set value in the exposure control device of the film scanner of FIG. 1;

FIG. 3 is a flowchart illustrating details of a process of changing an analog set value in steps S203 to S205 of FIG. 2;

FIG. 4 is a flowchart illustrating an initial setting operation process of an analog set value in an exposure control device of a film scanner according to a second embodiment of the present invention.

FIG. 5 is a flowchart showing details of a process of changing an analog set value in steps S403 to S406 of FIG. 4;

FIG. 6 is a flowchart showing an analog setting value initial setting operation process in an exposure control device of a film scanner according to a third embodiment of the present invention.

FIG. 7 is a flowchart showing details of a process of changing an analog set value in steps S603 to S606 of FIG. 6;

FIG. 8 is a flowchart illustrating an initial setting operation process of an analog set value in an exposure control device of a film scanner according to a fourth embodiment of the present invention.

FIG. 9 is a flowchart showing details of a process for changing an analog set value in steps S803 to S807 in FIG. 8;

[Explanation of symbols]

 101 Lamp 102 Film Folder 103 Lens 104 CCD Line Sensor (CCD) 109 Analog Image Processing Circuit 110 A / D Converter 111 Image Processing Unit

Continued on the front page F term (reference) 2H110 AA01 AA21 AB06 CB33 CB44 CB72 CD05 5C051 AA01 BA03 DA03 DB22 DB28 DC04 DC05 DC07 DE30 5C062 AB03 AB17 AB32 AB40 AC12 AC27 5C072 AA01 BA08 CA02 DA12 DA18 FB12 NA01 NA05 QA06 VA03

Claims (10)

[Claims] A scanning means for scanning a film on which image information is recorded; an illuminating means for illuminating the film; reading the image information at an arbitrary aperture ratio; amplifying the read image information; Exposure control means for performing control, wherein the exposure control means, the scanning speed of the scanning means based on the output value read the base area of the film, the light amount of the illumination means An exposure control device for controlling the exposure while controlling the amplification factor to approximately one by adjusting at least one of the aperture ratios. 2. An exposure control apparatus for a film scanner according to claim 1, wherein said exposure control means adjusts the aperture ratio preferentially. 3. An exposure control device for a film scanner according to claim 2, wherein said exposure control means adjusts the light amount preferentially. 4. An exposure control device for a film scanner according to claim 2, wherein said exposure control means adjusts said scanning speed preferentially. 5. The exposure control device according to claim 1, wherein the output value comprises a voltage value of an RGB signal. 6. A scanning step of scanning a film on which image information is recorded, an illumination step of illuminating the film, reading the image information at an arbitrary aperture ratio, amplifying the read image information, and exposing the image information. An exposure control method for an exposure control device of a film scanner, comprising: an exposure control step of performing control, wherein the exposure control step includes: a scanning speed of the scanning step based on an output value obtained by reading a base area of the film; An exposure control method for a film scanner, wherein the exposure control is performed by controlling at least one of the amount of light in the process and the aperture ratio so as to suppress the amplification factor to approximately one. 7. The exposure control method for a film scanner according to claim 6, wherein the exposure control step adjusts the aperture ratio preferentially. 8. The exposure control method for a film scanner according to claim 7, wherein said exposure control step adjusts the light amount preferentially. 9. The exposure control method for a film scanner according to claim 7, wherein in the exposure control step, the scanning speed is preferentially adjusted. 10. The film scanner exposure control method according to claim 6, wherein the output value comprises a voltage value of an RGB signal.