JPS63261958A - Method and device for reproducing set density area of picture signal - Google Patents

Abstract

PURPOSE:To reproduce a former set density and a former hue at a high precision even after the release of a set-up, and to facilitate the correcting operation of a set density area by detecting and storing the set data of a highlight and a shadow, and reading out the data as occasion demands. CONSTITUTION:A switching circuit 14 is switched to 0V by a switch signal (k) from a control part 11, and a constant-voltage generation circuit 10 and a voltage regulation circuit 12 are activated by chip select signals CS1, CS2. A gain is fixed by giving a shadow setting data D2 to the circuit 12, and the circuit 10 is given a highlight setting data D1, and a voltage signal, corresponding to it, is inputted to an operational amplifier 9. The blue light component of a highlight point is inputted to the amplifier 9 through a photo-multiplier tube 7 and a logarithmic amplification circuit 8. A difference signal (c) passes through the circuit 12 and is compared with 0V by a comparator 13, and the signal (e) is stored in a disk 18 through an A/D converter 15 and the control part 11. Similarly to this highlight point, a shadow point is set by switching the circuit 14 into -3V. A green and a red components are similarly processed. The data of the disk is read out as occasion demand.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for reproducing a set density range of an image signal used in the setup of a photoelectric scanning image recording device such as a so-called color scanner or monochrome scanner. .

(Prior art and its problems) In photoelectric scanning image recording devices such as color scanners and black-and-white scanners, each dial on the operation panel is adjusted before scanning to obtain the desired duplicate image for each original image. Setup work is performed to configure the As part of this setup work, there is density range setting work, and the purpose of this is to convert the density range of the original image into a predetermined density range on the reproduced image. The original image density range is set by operating the highlight setting dial and shadow setting dial according to the density.

FIG. 3 shows an example of a density range setting circuit A of a conventional color scanner. However, in Figure 3 they are blue and green.

Only the density range setting circuit A for the blue light component is shown among the red three-color light for sharpening and the one to three-color light for unsharpening, and the density range setting circuit for green light, red light, and others is shown for blue light. Since it has the same configuration as that of , its illustration is omitted.

This density range setting circuit A is equipped with a photomultiplier tube 1 for receiving blue light, and the light that has passed through or reflected from the color original is collected by a pickup lens and used in a dichroic mirror spectroscopy system to separate blue, green, and red light. After being separated into three colors and other colors, the blue light is guided to the photomultiplier tube 1.

Similarly, the green light, red light, and other lights separated by the spectroscopic system are configured to be guided to respective photomultiplier tubes. The density range setting circuit A sets the density range for blue light as follows. First, the blue light obtained by picking up the highlight points of the color original is guided to the photomultiplier tube 1, and the blue signal photoelectrically converted by the photomultiplier tube 1 is sent to the logarithmic amplifier circuit 2 for signal processing that will be performed later. Logarithmically compressed to facilitate. Next, the resistance value of the volume 3 is changed by operating the highlight setting dial for blue light, and the voltage value on the output side of the operational amplifier 4 is adjusted to Ov while looking at the display on the display panel (not shown). As a result, the voltage value on the output side of the operational amplifier 5 is adjusted to 5.times., and the setup of the highlight point for blue light is completed. Setting up highlight points for other lights is done in the same way as above, by operating the respective highlight setting dials. Next, move the pick-up position of the color original image from the highlight point to the shadow point, first operate the shadow setting dial to change the resistance value of volume 6, and turn on the operational amplifier 5 while watching the display on the display panel (not shown). Adjust the voltage value on the output side to 2■. This completes the setup of the shadow point for blue light. Setup operations for other lights are performed in the same manner as above by operating the respective shadow setting dials.

However, with the above setup method, each time a new color original image is set up, the setup of the previous color original image is canceled. If you need to rescan with a color scanner, you will have to go through the setup process again. At that time, if the reproduction of highlights and shadows in the previous color separation result was good, you would like to reproduce the density range setting work exactly as before, or if the reproduction of at least one of the highlights and shadows was poor. needs to modify the previous settings. However, because it is not possible to accurately match the pick-up position of the color original image to the original highlight and shadow points, the original set density range cannot be accurately reproduced. The problem was that it was difficult to reproduce or correct the problem.

A similar problem occurs when reproducing or modifying the set density range of a black and white scanner.

(Object of the Invention) This invention was made to solve the above-mentioned conventional problems, and it is possible to reproduce the original set concentration range with high accuracy even after the set-up is canceled, and it is possible to correct the set concentration range. An object of the present invention is to provide a method and apparatus for reproducing a set density range of an image signal, which can easily perform the following.

(Means for Achieving the Object) The method for reproducing a set density range of an image signal, which is the first invention, includes highlight setting data that sets the voltage level of an image signal of a highlight part of an original image to a first predetermined level. Detecting and storing shadow setting data for setting the voltage level of the image signal of the shadow portion of the original image to a second predetermined level, and reading out the highlight setting data and shadow setting data as necessary. The set density range of the image signal is reproduced using the image signal.

Further, the second invention is a device for reproducing a set density range of an image signal, which is a device for realizing the above method, and adjusts the voltage level of an image signal of a highlight portion of an original image based on highlight setting data. The image forming apparatus includes a highlight setting means and a shadow setting means for adjusting the voltage level of the image signal of the shadow part of the original image based on shadow setting data. Furthermore, highlight setting data sets the voltage level of the image signal of the highlight part of the original picture to a first predetermined level, and shadow setting data sets the voltage level of the image signal of the shadow part of the original picture to a second predetermined level. A control section is provided to detect this, and the highlight setting data and shadow setting data detected by the control section are stored in the storage means. The highlight setting data and shadow setting data stored in the storage means are applied to the highlight setting means and the shadow setting means as necessary to reproduce the set density range of the image signal. .

(Embodiment) FIG. 1 shows a schematic configuration diagram of a set density range reproducing apparatus which is an embodiment of the present invention, and shows an example applied to a color scanner. As shown in the figure, a photomultiplier tube 7 for receiving blue light is connected to an operational amplifier 9 via a logarithmic amplifier circuit 8.
” terminal, and the “-” terminal of the operational amplifier 9 is connected to a constant voltage generating circuit 10 (for example, National Se
a+1 conductor rDAcO832J)
It is configured so that the output signal of is inputted. The constant voltage generation circuit 10 is activated by a chip select signal C81 output from the control section 11, and generates 256 different voltage levels based on, for example, 8-bit highlight setting data D1 read from the memory in the control section 11. It is configured to output a constant voltage signal for highlight setup having a level. This constant voltage generating circuit 10
and the operational amplifier 9 constitute a highlight setting means.

The output terminal of the operational amplifier 9 is connected to the input terminal of a voltage adjustment circuit 12 (for example, rDACO832J manufactured by National Semlconductor). The voltage adjustment circuit 12 is activated by a chip select signal C32 output from the control section 11, and adjusts the output signal C of the operational amplifier 9 based on, for example, 8-bit shadow setting data D2 read from the memory within the control section 11. 25
It is configured to create an output signal d with a voltage level amplified by six different gains. This voltage adjustment circuit 12 constitutes a shadow setting means.

The output signal d of the voltage adjustment circuit 12 is sent to the next stage color correction circuit (
(not shown) and one input terminal of the comparator 13. A common contact of a switching circuit 14 is connected to the other input terminal of the comparator 13, and the switching circuit 14 selects the OV side terminal and the -3V side terminal according to the switching signal k output from the control section 11. It is configured so that it can be switched and connected. The output terminal of the comparator 13 is connected to the control section 11 via the A/D converter 15. Connected to the control unit 11 are a keyboard 16 for inputting various command signals, and a display unit 17 composed of a CRT or the like, and a floppy disk or the like for storing highlight setting data and shadow setting data. A storage unit 18 consisting of is connected.

In FIG. 1, photomultiplier tube 7. Logarithmic amplifier circuit 8.
Operational amplifier 9. Constant voltage generation circuit 10. Voltage adjustment circuit 12
．． Comparator 13. The switching circuit 14 and the A/D converter 15 constitute a density range setting circuit 19 for blue light, and a density range setting circuit (not shown) for other lights having the same configuration is also configured in the control unit 11. It is connected to the.

The setup of highlight points and shadow points by this device is performed as follows. However, in this color scanner, it is assumed that the voltage level of the signal d input to the color correction circuit is adjusted so that the voltage level at the highlight point and Ov1 is 13cm at the shadow point.

First, the input light obtained by picking up the highlight points of the color original image is guided to the photomultiplier tube 7 of the blue light density range setting circuit 19 (as well as to other The light is guided to each photomultiplier tube of each concentration range setting circuit (not shown).Next, the keyboard 16
A highlight set-up command is given to the control section 11 from . Upon receiving the highlight set-up command, the control section 11 executes a highlight set-up operation for blue light and then other lights in accordance with a program stored in a memory within the control section 11. First, the highlight setup operation for blue light will be explained.

(2) First, the switching circuit 14 is switched to 0 (2) by the switching signal k.

(2) Activate constant voltage generation circuit 10 and voltage adjustment circuit 12 by chip select signals C81 and C82.

(2) Give predetermined shadow setting data D2 to the voltage adjustment circuit 12 to determine the gain of the voltage adjustment circuit 12; The shadow setting data D2 given at this time can be selected appropriately, but
Here, for the sake of convenience, it is assumed that shadow setting data D2 that sets the gain to "1" is provided.

(2) Give the first highlight setting data D1 to the constant voltage generation circuit 10. As a result, the highlight setting data D
1, the signal a with a voltage level corresponding to
−” terminal. On the other hand, operational amplifier 9
Since the blue light component of the highlight point is charged and converted by the photomultiplier tube 7 and then logarithmically compressed by the logarithmic amplifier circuit 8 is given to the "+" terminal of the signal a.
A signal C having a voltage level corresponding to the difference between the two is outputted from the operational amplifier 9. This signal C has a gain of “1”.
The signal d is inputted to one input terminal of the comparator 13 as a signal d having the same voltage level as the signal C, through the voltage adjustment circuit 12 set to . Since the other input terminal of the comparator 13 is given a potential of 0■ via the switching circuit 14, the comparator 13 outputs a signal e having the same voltage level as the signals c and d. is converted into a digital signal f by the A/D converter 15 and provided to the control section 11.

■In the I control section 11, based on the digital signal f,
For example, when the signal value is positive, the address of the memory in the control unit 11 is incremented, and when it is negative, it is decremented, and the next highlight setting data D1 is such that the value of the signal f approaches O. is read out and applied to the constant voltage generation circuit 10.

■ Repeat the operation in ■ above until the value of the digital signal f converges to 0, and thus set the value of the signal f to O.
In other words, highlight setting data D1 with the voltage level of signal C set to Ov is detected. This completes the highlight setup for blue light.

■Next, do the above ■~ for other circuits simultaneously or sequentially.
Perform setup using the same procedure as in ■.

In this way, when the highlight point setup work for the three-color light and others is completed, a highlight set-up completion indication is displayed on the display section 17, and the operator then selects the pick-up position of the color original from the highlight point. After moving to the shadow point, a shadow set-up command is given to the control S section 11 from the keyboard 16. The control unit 11 receives the shadow set-up command and executes the blue light component and other shadow set-up operations according to the program stored in the memory within the control unit 11. First, the shadow setup operation for blue light will be explained.

■First, the switching circuit 14 is set to -3VIQ by the switching signal k.
Switch to IJ.

(2) Activate the voltage adjustment circuit 12 by the chip select signal C82. The highlight setting data D1 detected in steps (1) to (2) above is held in the constant voltage generation circuit 10. At this time, since the shadow points of the color original image are picked up, the voltage level of the signal S is smaller than the voltage level of the signal a, and therefore the signal C has a negative voltage level corresponding to the difference between the signal a and the signal C. It will be output from the operational amplifier 9.

■The voltage adjustment circuit 12 receives the first shadow setting data D2.
give. As a result, the voltage level of the signal C is amplified by the gain specified by the shadow setting data D2,
This signal d is output as a signal d, and this signal d is output to the comparator 13.
is applied to one input terminal of . Since the other input terminal of the comparator 13 is given a potential of 13V via the switching circuit 14, the polarity of the signal e output from the comparator 13 is positive if the signal d is greater than 13V. , conversely, if it is small, it becomes negative. This signal e is A/D
It is converted into a digital signal f by the converter 15 and sent to the control unit 11.
given to.

Based on the signal f, the 0 control unit 11 increments the address of the memory in the control unit 11 when the signal value is positive, and decrements it when it is negative, thereby setting the value of the signal f to 0. The next shadow setting data D2 that can be approximated is read out and applied to the voltage adjustment circuit 12.

[Co., Ltd.] Repeat the above operation 0 until the value of the signal f converges to O, and in this way set the value of the signal f to O, in other words, create the shadow setting data D2 that sets the voltage level of the signal d to -3■. To detect. This completes the highlight setup for blue light.

0 Next, perform the above ■~ for other circuits simultaneously or sequentially.
Perform setup using the same procedure as @.

When setting up the shadow points for the three-color light and others is completed in this way, a shadow set-up completion message is displayed on the display section 17.The operator then operates the keyboard 16 to set up the detected three-color light and other shadow points. Highlight setting data and shadow setting data are stored in a floppy disk 18 in association with data specifying a color original picture.

By the way, when I created the Y version, 9M version, 0 version, and BK version by scanning with the above-mentioned highlight and shadow setup state, and when I printed using these versions, I noticed that the printed matter had a color cast, If you need to make color corrections and need to rescan with a color scanner, you can do the following:
Modify the set density range for colored light. First, data specifying a color original image and a data read command are given to the control section 11 from the keyboard 16 . As a result, the highlight setting data and shadow setting data for the three color lights and others of the color original image to be corrected are read out from the floppy disk 18, and the constant voltage generation circuit 10 and the voltage adjustment circuit of the three color light and other density range setting circuits are read out. 12, and the original set density range is accurately reproduced as the set density range of each density range setting circuit. Therefore, the operator inputs a necessary setting density range correction command from the keyboard 16 based on the state of color cast, etc. of the printed matter, and corrects only the required highlight setting data or shadow setting data to prevent color cast, etc. from occurring. It becomes possible to easily correct the concentration to the set concentration range.

FIG. 2 shows a schematic diagram of a set density range reproducing apparatus according to another embodiment of the present invention. However, in this embodiment, it is assumed that the voltage level of the signal d input to the color correction circuit is adjusted so that it becomes 5■ at the highlight point and 2■ at the shadow point. In this device, a highlight setting means is composed of a volume 20, a pulse motor 21 for driving the volume operation knob, a rotary encoder 22 for detecting the volume operation position, and an operational amplifier 23.
, a pulse motor 25 for driving a volume control knob, and a rotary encoder 26 for detecting a volume control position.
The operational amplifier 27 constitutes a shadow setting means. The other configurations are the same as those of the above embodiment. To set up a highlight point using this device, with the switching circuit 14 switched to the 5V side, adjust the volume 20 using the pulse motor 21 so that the voltage level of the signal C becomes OV, and then adjust the volume 20 at that time. The adjusted position is detected by the rotary encoder 22 and stored in the floppy disk 18 as highlight setting data. To set up the shadow point, switch the switching circuit 14 to the 2V side while keeping the volume 20 at the highlight set-up position, and adjust the volume 20 so that the voltage level of the signal d becomes 2V.
4 is adjusted by the pulse motor 25, the adjusted position of the volume 24 at that time is detected by the rotary encoder 26, and the shadow setting data is stored on the floppy disk 18.
to be memorized. With this device, the volume 20, 24 can be operated based on the highlight setting data and shadow setting data stored in the floppy disk 18 to accurately reproduce the original set density range, so that the printed matter may not have color cast. When this occurs, the set-up can be reproduced and the set-up can be easily corrected to a set density range in which color cast or the like does not occur. Even if the original image has a color shift, if you perform highlight setting and shadow setting at the highlight points and shadow points on the original image, the hue setting can be reproduced and the same or better effect can be obtained.

In the above embodiment, a case has been described in which the set density range for the color signals of three color lights and others in a color scanner is reproduced and corrected, but this invention reproduces and corrects the set density range of the density signal in a monochrome scanner. It is also applicable in the same way.

(Effects of the Invention) As described above, according to the method and apparatus for reproducing a set density range of an image signal of the present invention, highlight setting data and shadow setting data are detected and stored, and these data are read out as necessary. Since the set density range is reproduced using the settings, even after the setup is canceled, the original set density range and hue can be reproduced with high accuracy, making it easy to correct the set density range. can get.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a set density range reproducing device according to an embodiment of the present invention, FIG. 2 is a schematic diagram of a set density range reproducing device of another embodiment, and FIG. 3 is a conventional density range setting diagram. A schematic diagram of the circuit is shown. 9.23.27... Operational amplifier, 10... Constant voltage generation circuit, 11... Control unit, 12... Voltage adjustment circuit, 18... Floppy disk, 20.24... Volume, 21 .25...Pulse motor,

Claims (2)

[Claims] (1) Detect and store highlight setting data that sets the voltage level of the image signal in the highlight part of the original picture to a first predetermined level, and set the voltage level of the image signal in the shadow part of the original picture to a second predetermined level. A method for reproducing a set density range of an image signal, which detects and stores shadow setting data to be set to a level, and reads out the highlight setting data and shadow setting data as necessary to reproduce the set density range of the image signal. (2) Highlight setting means for adjusting the voltage level of the image signal in the highlight part of the original picture based on highlight setting data; and shadow setting means for adjusting the voltage level of the image signal in the shadow part of the original picture based on the shadow setting data. and highlight setting data that sets the voltage level of the image signal in the highlight portion of the original image to a first predetermined level, and shadow setting data that sets the voltage level of the image signal in the shadow portion of the original image to a second predetermined level. and a storage means for storing the highlight setting data and shadow setting data detected by the control section, and storing the highlight setting data and shadow setting data stored in the storage means. A device for reproducing a set density range of an image signal, characterized in that the set density range of an image signal is reproduced by applying the data to the highlight setting means and the shadow setting means as necessary.