JPS6366681A - Method for extracting and processing memo information written by color pen - Google Patents

Abstract

PURPOSE:To separate memo information written by a color pen with high accuracy by forcibly opening and closing a shutter to obtain a state where the rising/falling characteristics of a electric signal obtained after photoelectric conversion are varied by colors in a document. CONSTITUTION:Reflected light sent from an original 2 where the memo information is written by a color pen is separated into three primary colors by a prism 4A. Each separated color light is transmitted through a shutter 5 which transmits and cuts repetitively each color light with a fixed frequency and the timing shifted for each color light. The light passed through the shutter 5 is condensed again by a prism 4B and a lens 3B and subjected to photoelectric conversion through a photodetecting sensor 6. Then the obtained electric signal is sampled synchronously with the open/close frequencies of the shutter 5. The variation value of the signal intensity is read at the rise and the fall of the electric signal and this variation value is binarized with the threshold value set previously. Then character information written in black is separated from the memo information written by a color pen.

Description

Detailed Description of the Invention (3.1 Field to which the Invention Pertains) The present invention relates to a method for extracting memo information written with a nine-color pen, and in particular, a method for extracting memo information written with a nine-color pen, in particular, a method for intentionally changing the state of change in a luminance signal depending on the color to be extracted. The present invention relates to an extraction processing method for separating and extracting memo information written in three documents with a colored pen.

(3, 2 Prior Art) In order to separate and extract memo information written in a document using a colored pen, the document is input into a computer as multivalued black and white information using an image input device such as Image League. Using the property that the signal strength (optical density) of the colored pen is between the signal strength of the paper and the signal strength of the characters written in black, as shown in Figure 6, two-stage By setting the thresholds (A, B) and binarizing the information of the 9-color pen using the two thresholds A and B, and taking the exclusive OR, one separation, as shown in Figure 7, is obtained. There are known methods of extraction. Also, the document is red (R).

There is a method of separating and extracting memo information written with a one-color pen using a color image scanner that can extract signal intensities (density information) of the three primary colors of green (G) and blue (B). In the former method, the signal strength (optical density) of areas painted solidly or traced multiple times with a 9-color pen falls within the range of the signal strength (optical density) of characters written in black in the document, and 6 It is difficult to set the threshold level of B shown in Figure 2.
In addition to memo information written with colored pens, the original text can also be extracted, and conversely, the signal strength (optical density) of memo information written with extremely light colored pens falls within the range of the optical density of the paper surface. Depending on the setting of threshold value A in Figure 6, the information may be extracted in a blurred state, so in order to accurately extract memo information written with colored pens, the selection of colored pens and the writing method must be strict. There was a need. On the other hand, in the latter method,
Because it uses data in the three primary colors of red, green, and blue as input information, it is suitable for separating black-and-white information from color information.

In order to extract a small amount of color information written in a black and white west side, the amount of information is three times that of black and white, and therefore the memory capacity and processing time are also increased compared to the above method.

This is not a simple input method, and color image scanners are much more expensive than black and white image scanners, making them unsuitable as simple input means.

(3.3 Purpose of invention) The purpose of the present invention is to capture the light reflected from the paper surface once.

The three primary colors of light are separated, and each color of light is passed through a shutter that repeats transmission and blocking at a fixed frequency and at different timings for each color of light.

The amount of change in signal strength at the rise and fall of the electrical signal obtained by focusing the light again and performing photoelectric conversion using the light receiving sensor is read. Traditionally, by performing separation and extraction using the generation of different signal patterns when operating.

To provide a method for solving the instability that occurs when the difference in color density of reflected light obtained from a document is separated by a method of extracting it as a level difference in signal intensity.

(3, 4 Configuration of the Invention) The present invention creates a state in which the rise and fall characteristics of the electrical signal obtained after photoelectric conversion differ depending on the color in the document by forcibly opening and closing the shutter.

The main feature is to separate memo information written with colored pens. Conventional technology uses only the intensity difference when extracting nine-color information as a black and white signal, or uses three-color information of red, green, and blue to read color information written with a colored pen with three times the amount of information compared to black and white. They were very different in that they were separated.

(Embodiments 3 and 5) Figure 1 shows an embodiment of the present invention, in which 1 is a white light source, 2 is a white light source, and 2 is a white light source.
is the original, 3 is the lens group, and 4 is the prism.

5 is a shutter, 6 is a light receiving sensor, 7 is an A/D conversion circuit,
8 is a calculation circuit. Figure 2 shows an example of the operation of the shutter shown in Figure 1 and an example of the signal taken out.
, 10.11 shows an example of the operation of each red, green, and blue shafter.
2 shows the states of each signal of the paper surface (white), memo information written with a red pen, and black text information obtained after photoelectric conversion by the light receiving sensor. The target document here refers to a printed or copied document in which memo information is written with a colored pen.

Here, assuming that the memo information written on the document is red, we will describe the process of separating and extracting text information (black) and red memo information from one page (white screen). The light reflected from the original is separated into colors by a prism (4-A), and here a shutter (5) is provided for light corresponding to red, green, and blue to allow each color light to pass through.

In order to separate the red color information that is blocked from the black and white information, the shutter is opened and closed according to the red, green, and blue shutter opening/closing pattern shown in 9.10.11 in FIG. The light passing through this shutter is passed through a prism (4-B),
The lens (3-B) collects the light again and sends it to the light receiving sensor (
6) receives the light and performs photoelectric conversion. The electrical signal thus obtained is sampled by an A/D conversion circuit (7) in accordance with the opening/closing frequency of the shutter and converted into a digital signal. As shown in FIG. 2, in the signal (12) shown on the paper (white), if all the shutters are open, the signal strength is ■1, and when the red shutter is closed, the signal strength is ■. □, when all shutters are closed, the signal strength is O, which is equal to the black state. In addition, the signal strength of the memo information written with the red color pen is because only the red light output is obtained when all shutters are open.

The value is Vllll, and since no light other than red is reflected when the red shutter is closed, the value is 0, which is the same as when all shutters are closed. On the other hand, for text information written in black, the reflected light is 0 even if all the shutters are open, and the intensity of the output signal is not affected by the opening and closing of the shutters.

In this way, the rise and fall characteristics differ depending on the shutter state and whether the paper, black text, or memo information is written in red pen. Also, the signal (1
2) is a signal whose signal strength changes in a specific pattern for each color to be read as the shutter opens and closes, and is obtained sequentially along the main scanning direction of the document, so all The signal strength when the shutter is open is X@n-t + when only the red shutter is closed is X ff*-1 + when all shutters are closed is X3n
(=O). (Here, n=1.2, 3.
...') By sequentially inputting the signals digitized at the shutter sampling frequency in the A/D conversion circuit (7) to the calculation circuit (8), color separation can be performed in the following steps. . The above signals are sequentially taken in in calculation cycle B (8). X3n- as the th signal and X3□
Take the difference with the 7th signal.

Amount of decrease in signal strength ΔV1 when operating the red shutter
seek. Namely.

ΔV 1 =V (Xsll-z) V (X3,
1-1) is obtained. Next, a difference Δv2 is found between the X5a-1st signal, which is the signal output when the red shutter is operated, and the X3nth signal, which is the signal output when all shutters are closed. That is, AV2-V (Xs
−−+) V (Xs−) is obtained. In this way, when scanning the paper (white) part, O<Δv1<ΔV2, and in the memo information part written in red.

ΔVl>0. Δv2=0. Furthermore, the text information written in black is ΔV1 = Δv2
=0.

In this way, it is possible to separate color information by utilizing the fact that the relationship between ΔV1 and Δv2 changes depending on whether the two pages (white), memo information written in red pen, or text information written in black. . The most simple separation procedure is to separate color information according to the flow shown in FIG. As a first step, Δ■1>0 is determined and the information is separated into 8 pages (white) and red memo information or text information written in black. next.

By determining Δv2>0, it is determined whether the memo information is paper (white) or red. The actual problem is that when the density difference is small between the red memo information and the white information on the paper or between the black text information, the threshold for separating red from white and red from black from the obtained signal is Setting the value was difficult, but as in the present invention, a shutter is used to forcibly remove a specific color component, and the pattern of output reduction due to the shutter differs depending on the color. This method has the advantage of being easier than the threshold setting method.

Here, for the shutter that blocks and transmits the color light separated by one color, a shutter that is electrically capable of repeating blocking and transmitting operations at high speed, such as a liquid crystal shutter, is used, for example.

In this way, the seven documents are illuminated with white light, and the reflected light is once separated into colors and then focused again to perform photoelectric conversion, so the signals obtained are black and white density information.

Furthermore, this signal is periodically interrupted by a shutter located between the two-color separation filter and the light receiving sensor.

Since it converts repeatedly transmitted light into an electrical signal, it is possible to obtain color information for eight colors by changing only the timing of the shutter opening and closing frequency while keeping it constant for each color light. It is.

In this case, the opening/closing operation 1 of the shaft as shown in FIG.
3.14.15 to obtain 16 output signals for each color. Sampling signal X5h-t* of output signal 16
X311-1+ X2. Since l means the intensity of red, green, and blue, respectively, perform A/D conversion and store the results in red, green, and blue memories sequentially to obtain color natural image information with shading. You can also do that. Also, A
If the threshold for binarization is set in advance during /D conversion, white, black, and red can be obtained by processing according to the flow shown in Figure 5.

It is also possible to easily separate the colors into eight colors: green, blue, yellow, cyan, and magenta. Conventionally, even when using a colored pen, it is difficult to see a clear difference in signal strength (optical density) between black and white, such as a single character written in black and red written in dark colors, or white and paper written in light red, etc. By repeating forcibly transmitting and blocking light using a shutter provided for each color light, it is possible to create a signal pattern corresponding to the color, and thereby the color information in a document can be determined from the characteristics of the signal. Therefore, by opening and closing the shutters provided for the three primary colors of light, noise and other components that are likely to be included in the output when two documents are irradiated can be removed, allowing for more stable separation.

(3, 6 Effects of the Invention) As explained above, according to the present invention, the color light after color separation is operated by operating the detectors provided for each color at a certain frequency to block and transmit the light, and then re-inspect these lights. When colored light is focused and photoelectrically converted by a light-receiving sensor, the characteristics of the change in signal output are different depending on the character part (black), the part written with a colored pen (for example, red), and the paper surface (white). This method is much more accurate than the conventional method of separating signals based on signal strength alone. In addition, the input section can be configured with a light source, a color separation filter such as a prism, a light shutter, a light receiving sensor, and some lens systems.Moreover, since the signal extracted is a black and white luminance signal, the light source and light receiving sensor input black and white images. What is used in the device can be used as is. Accordingly, the present invention provides a three-color light source of red, green, and blue as seen in conventional color image input devices, and a means for switching between the three-color light sources, as well as red and green light sources.

Since there is no need for a means for receiving color-separated light using light-receiving sensors corresponding to the three colors of blue, there are also advantages in that the structure can be simple and miniaturization can be achieved. Further, the shutter used in the present invention only needs to be capable of transmitting and blocking light at high speed, and does not need to have transmission or absorption characteristics for a specific color. Also for red, green, and blue colored light.

By independently setting the opening and closing cycles of the shutters, it is also possible to separate the color information of eight colors from the change characteristics of the signal for one color while also extracting it while handling black and white density information.

[Brief explanation of drawings]

FIG. 1 shows one embodiment of the present invention, and FIG. 2 shows an example of a signal obtained when the system shown in FIG. 1 is operated. Figure 3 shows the process carried out in the calculation circuit to separate white, red and black, and Figure 4 shows an example of shutter operation and output signals to separate color information into eight colors. Figure 5 shows the process of separating the signal obtained by the shutter operation example shown in Figure 4 into eight color information, Figure 6 shows the conventional method of extracting memo information, and Figure 7 An extraction logic explanatory diagram is shown. 1. A manuscript with memo information written using a white light source and a 29-color pen; 3. lens group, 40-color separation filter prism), 5. Shafter, 6. Light receiving sensor? , A/D conversion circuit, 8. Calculation circuit, 9.10.11.13.14,15
．． Shutter operation pattern, 12.16. Output signal of the light receiving sensor. Patent Applicant Nippon Telegraph and Telephone Corporation Patent Attorney Mori 1) Hiroshi V, 1 Fig. 2 Fig. 5n-z 2 No. 6121 White Black + Fig. 7

Claims (1)

[Claims] In a document input device that inputs character information by scanning a document, in order to separate and extract memo information written in the document with a colored pen, the document is illuminated with a white light source and the reflected light is filtered using a spectral filter. The light is separated into the three primary colors of red, green, and blue, and passed through a shutter that operates at a constant opening/closing frequency and with different opening/closing timing for each color of light. Each color of light is then focused again and sent to a light receiving sensor. The focused light is photoelectrically converted, the resulting electrical signal is sampled in synchronization with the shutter opening/closing frequency, and the amount of change in signal intensity at the rise and fall of the signal is read.
This color pen is characterized by converting the amount of change into a binary value using a preset threshold, and separating and extracting text information written in black and memo information written with a colored pen. How to extract written memo information.