JPH0374966A - Transmitter for original with photograph - Google Patents

Abstract

PURPOSE:To read and send a character area and a photograph area with excellent reproducibility by reading a data from a 1st storage means in the character area through the result of identification of a character photograph identification means, reading the data from a 2nd storage means in the photograph area and sending the readout data. CONSTITUTION:An original D with a photograph is read simultaneously in two modes, a binarizing mode and an intermediate tone mode and stored separately into storage means 27,28. Then a read signal of the character area is read from the 1st storage means 27 stored in the binarizing mode and the read signal in the photograph area is read from the 2nd storage means 28 stored in the intermediate mode with a signal from a means MPU identifying the character area and the photograph area and sent. Thus, a read signal with excellent reproducibility is sent from both the character section and the photograph section even from an original D with a photograph.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for successfully transmitting a document containing photographs.

Among the facsimile machines that are currently popular as indigo sitting document transmitting devices, there are some that are equipped with two reading modes: a binary mode and a halftone mode.

Here, the binarization mode is for reading a document image by converting it into black and white, and is suitable for reading a text document. On the other hand, in halftone mode, the density gradient from white to black is represented by the number of gradations such as 16 gradations and 32 gradations, and it is converted into a gradation signal according to the image density and read, making it suitable for reading photographic originals. ing.

However, manuscripts sent by facsimile machine include manuscripts with only text, manuscripts with only photographs, and manuscripts with text partially containing photographs (hereinafter referred to as manuscripts with photographs). There are three types. Among these, the first two can be clearly read by switching between the binary mode and the halftone mode on a facsimile machine equipped with the halftone mode mentioned above. No matter which mode is used, it is not possible to clearly read an image of an incoming original.

In other words, if the above document is read in binarization mode, the photographic area will be rendered black and the image imprinted therein will be unrecognizable; on the other hand, if it is read in halftone mode, the photographic area will be reproduced clearly. However, the text may appear thin, making it very difficult to read.

In view of these points, it is an object of the present invention to provide a useful transmitting device that can read and transmit both character areas and photographic areas with good reproducibility.

In order to achieve the above-mentioned object, the present invention provides character/photo identification means for identifying character areas and photographic areas on a document, and a second system for storing signals read by the document reading means in a binary mode. 1 storage means and a second storage means for storing the signals read by the document reading means in halftone mode, and according to the identification result of the character/photo identification means, in the character area, the signals from the first storage means are stored. On the other hand, in the photo area, data is read from the second storage means and transmitted over the line.

According to the present invention, a photographic original is simultaneously read in two modes, a binarization mode and a halftone mode, and stored in separate storage means. Then, the reading signal of the character area is read out from the first storage means stored in the binarization mode and transmitted by the signal from the means for identifying the character area and the photographic area, and the reading signal of the photographic area is transmitted in the halftone mode. The second memorized in
is read from the storage means and transmitted. Therefore, even if the document contains photographs, reading signals with good reproducibility will be transmitted for both the text and photographic portions.

Figure 1 is a side sectional view showing a facsimile machine to which the present invention is applied. It has a receiving section B that prints on paper. Transmitter A
The document sheet on the document table L is separated one by one by the pinch roller 2 and the separation bat 3, and is conveyed through the image reading area E to the paper ejection roller 4.5.
It is discharged to the outside. In the image reading area E, a line light source 6 is provided.
The surface of the original is scanned with light as the original is transported. The reflected light from the surface of the original is reflected by a mirror 7.8, enters an optical reading section 9 consisting of a lens 9b and a CCD image sensor 9a, and is sequentially photoelectrically converted.

On the other hand, the receiving section B prints on the recording paper P wound in a roll using the thermal head 11 while feeding it out using the platen roller 12. When the printing for one page is completed, the recording paper P is fed out using the platen roller 12.
3 and 13b are operated to cut and discharge to the outside. Incidentally, Sl, section 2, and section 3 are paper detection sensors.

FIG. 2 is a block diagram of a transmitter incorporated in the facsimile machine. , in the figure, 20 is an oscillation circuit, and a reference clock from this oscillation circuit 20 is given to a timing control circuit 21.

This timing control circuit 21 outputs a control signal to the COD image sensor drive circuit 22 in accordance with the timing of charge transfer of the CCD image sensor 9a.

As a result, the drive circuit 22 outputs a transfer pulse to the CCD image sensor 9a. 23 is an amplifier circuit that amplifies the analog image signal read out from the CCD image sensor 9a by the transfer pulse. The output amplified by the amplifier circuit 23 is input to the analog processing circuit 24 . The analog processing circuit 24 consists of a sample hold circuit, an integrator, and a peak hold circuit. The sample and hold circuit functions to sample and hold at a sample rate that matches the timing of the transfer pulse, remove the transfer pulse superimposed on the image signal, and extract a continuous image signal. The image signal is output from the output line l. The integrator functions to remove high-frequency noise contained in the image signal sent from the amplifier circuit 23, and the output of this integrator is peak-held in the peak-hold circuit to generate the image signal for one line of the original. Create a white level signal inside. This white level signal is output from the output 'alt.

The analog image signal processed by the analog processing circuit 24 is supplied to a binarization processing circuit 25 and a halftone processing circuit 26 through an output line l.

The binarization processing circuit 25 consists of one voltage dividing resistor R and one comparator C. The voltage dividing resistor R2 has one end n1 connected to the terminal t to which the black level reference voltage Vo is applied, and the other end nt connected to the white level output 11alg.
A voltage dividing terminal n is connected to a comparison terminal of a comparator C.

Voltage dividing terminal n, is the white and black threshold level (threshold)
It is convenient to use a variable terminal as shown in the figure to adjust the threshold level as appropriate. An image signal is applied to the other input terminal of the comparator C through an output line l. When the image signal is higher than the threshold level given by the voltage dividing terminal, the comparator C output is H.
When the level is reversed, it becomes L level. The output of the comparator C is converted into a parallel signal by a serial barrel 1m unit S/P in units of 8 bits, for example, and is stored in the line memory 27 as a first storage means.

The intermediate processing circuit 26 includes a voltage dividing resistor R2, comparators C, %C, whose number is one less than the number of gradations, a multiplexer MPX, and a serial barrel converter S/P. The voltage dividing resistor R2 has both ends connected to the voltage dividing resistor R of the binarization processing circuit 25.
2, it is connected to the black level reference voltage V1 application terminal t and the white level output line 12, and is connected to the 15 voltage dividing terminals m.

~mls are connected to comparison terminals of comparators C1 to CIS. The voltage dividing terminal mlxmls divides the voltage between the white level and the black level according to the resistance value at that position.

The comparators C and -C+s compare the divided voltages of the divided voltage terminals mlxmls with the image signal applied to the other input terminal as reference human power. Assuming that the white level has the lowest voltage and the black level has the highest voltage as an image signal, when the image signal gradually increases from the white level to the black level, the output of each comparator 01 to CI5 will be as shown in the table in Figure 3. Change. In other words, it can be seen that the output combination patterns of all the comparators C1 to cps change by 16ijl while the image signal changes to the white level. Thus, the image signal is sent to the comparator C,-
C1, it is expressed with 16 gradations.

The outputs of all comparators C3 to CIS are sent to multiplexer MP
By switching X, each pixel is read out once, converted into a parallel signal through a serial/parallel converter S/P, and stored in the line memory 28 as a second storage means. Here, the order in which the comparator outputs are read out by the multiplexer MPX is controlled by the microprocessor MPU in a predetermined order so that halftone expression can be achieved by an area modulation method such as a dither method or a density pattern method. Therefore, the second storage means 28 stores each pixel as a signal expressed using the area step method.

29 is a counter that takes in the comparator output of the binarization processing circuit 25 line by line and counts the number of changes from "O" to "1". The ever-changing count value of this counter is input manually to a multiplexer unit MPU, which determines whether the reading position of the document is in a character area or a photo area.

This discrimination method divides one line of a read signal into a plurality of parts, calculates the density of the original image from a change in the count value of a counter for each divided part, and determines whether a text area is a photographic area. In the case of character areas, the line density in the main scanning line direction is low;
It is known that the line density is high in photographic areas, so
The above method makes it possible to reliably identify characters and photographs. The text/photo identification result is stored in the multiplexer unit MPU by expressing the boundary line between the text and the photo with the corresponding address signal of the image signal stored in the line memories 27 and 28, and is stored in the multiplexer unit MPU. Control switching. Therefore, the multiplexer 30 outputs the reading signal for the text area read from the first storage means 27 and the reading signal for the photo area read from the second storage means 28. (not shown).

Next, the operation of reading and transmitting a photo-containing original in the apparatus configured as described above will be explained. FIG. 4 is a diagram showing a manuscript with photographs, where D is a character area and D2 is a photograph area. Now, when the P position of this document is read in the main scanning direction, the analog processing circuit 24 outputs an analog image signal for one line shown in FIG. 5(A). This image signal is binarized by the 24M conversion processing circuit 25 and outputs a signal as shown in FIG. 5 (CB). However, this signal is the reference voltage Vs of comparator C.
The waveform is shown when is set to exactly the middle value between the black level and the white level. This binarized output is stored in the line memory 27 and inputted to the counter 29, where character areas and photo areas are identified from changes in line density. Note that the photographic area in Figure 5 (B) is shown with a wide pulse waveform for convenience, but in reality, this pulse waveform itself oscillates between the white level and the black level at extremely short intervals, as if modulated by a high-frequency signal. .

On the other hand, the analog image signal in FIG.
6 is also input, and here the gradation is expressed using 16 gradations.

Therefore, the halftone processing circuit 26 obtains a waveform as shown in FIG. However, the actual halftone output differs from such a waveform, and is a signal expressed by the area gradation method for each pixel. This signal is stored in line memory 28.

The signals stored in the two line memories 27 and 28 are switched and read out by a multiplexer 30. That is, the portion corresponding to the character area is read from the line memory 27,
The portion corresponding to the photo area is read out from the line memory 28 and transmitted.

Therefore, on the receiving side, text areas can be reproduced clearly in black and white using binary signals, and photographic areas can be reproduced with gradation using halftone signals.

Therefore, both text areas and photo areas can be reproduced in an optimal state.

FIG. 6 is a flowchart explaining the above operation.

In addition, although 16 gradations are shown as intermediate tones in the example,
Of course, the present invention can be implemented with other numbers of gradations such as 32 gradations.

As explained above, according to the present invention, it is possible to read and send a document containing a photo by automatically switching the text area to the binary mode and the photo area to the halftone mode. Both can be sent as optimal images, and the receiving side can reproduce a clear image that is close to the original image.

4,

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a facsimile element to which the present invention is applied;
FIG. 2 is a block diagram showing an embodiment of the present invention, FIG. 3 is a diagram showing the gradation expression operation of the halftone processing circuit, FIG. 4 is a diagram showing an original with a photo, and FIG. 5 is an original with a photo. FIG. 6 is a flowchart showing the operation. FIG. 1 9...Reading unit, 24...Analog processing circuit, 25
... Binarization processing circuit, 26 ... Halftone processing circuit, 2
7... first storage means, 28... second storage means,
29... Counter, MPU... Micro processor sensor unit (character/photo identification means), 30... Multiplexer

Claims (1)

[Claims] (1) Text and photo identification means for identifying character areas and photographic areas on a manuscript; first storage means for storing signals read by the manuscript reading means in a binarization mode; and signals read by the manuscript reading means. and a second storage means for storing in a halftone mode, and according to the identification result of the text/photo identification means, the text area is read from the first storage means, while the photo area is read from the second storage means. A device for transmitting manuscripts containing photographs, which is characterized in that it transmits over a line.