JPH09247439A - Image processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct desired marker processing in the marker processing of, e.g. a digital copying machine by accurately distinguishing a character signal with a low contrast and a marker signal or a marker and a character in the same color as a marker color in two color development. SOLUTION: A marker extract section 12 extracts a marker signal, a maximum value extract section 14 evaluates continuity of signals in a character image and detects a marker in an optimum way based on the evaluation data. Thus, a character signal with a low contrast and a marker signal in a copying machine of one color development or a marker color signal and a character signal in the same color as the color of the marker signal in a copying machine of two color development are discriminated accurately and then desired marker processing is conducted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and more particularly to an image processing apparatus for a digital copying machine.

[0002]

2. Description of the Related Art Conventionally, an image processing function by designating a marker pen is positioned as a general function of a digital copying machine and is often provided as standard equipment. In the one-color development digital copying machine, the marker signal is extracted only by the density information, and since the marker signal is read as the halftone signal, a high-contrast character signal and a marker signal can be distinguished. In the case of a low-contrast character or the like, as shown in (1), it is impossible to distinguish between the character signal and the marker signal, so that the erroneous detection of the marker occurs.

In the case of a two-color development digital copying machine, the marker is read as a color signal, but when there is a character of the same color as the marker color designated by the operator as shown in FIG. In this case, since the marker signal and the character signal cannot be distinguished, erroneous detection of the marker occurred.

[0004]

SUMMARY OF THE INVENTION The present invention solves the drawbacks of the prior art, makes it possible to accurately distinguish a marker signal from a character signal, and to perform the marker processing desired by the operator. The purpose is to provide a device.

[0005]

An image processing apparatus according to the present invention comprises input means for inputting a digital image signal, marker signal extracting means for extracting a marker signal from the digital image signal input to the input means, and inputting means. A maximum value extracting means for extracting a maximum value with respect to surrounding pixels of the digital image signal input to the means, a marker signal extracted by the marker signal extracting means, and a marker signal from the maximum value information extracted by the maximum value extracting means. It has extraction condition changing means for changing the extraction condition, and processing means for processing the digital image signal input to the input means by the marker signal obtained by the extraction condition changing means.

Further, the image processing apparatus of the present invention comprises input means for inputting digital image signals of at least two colors,
A marker signal extracting means for extracting a marker signal from the digital image signal input to the input means, a maximum value extracting means for extracting a maximum value with respect to surrounding pixels of the digital image signal input to the input means, and a marker signal extracting means. The extraction condition changing means for changing the extraction condition of the marker signal from the extracted marker signal and the information of the maximum value extracted by the maximum value extraction means, and the marker signal obtained by the extraction condition changing means are input to the input means. And a processing means for processing the digital image signal.

[0007]

1 is a block diagram of an embodiment of an image processing apparatus according to the present invention. The image processing apparatus of this embodiment mainly includes a digital image input unit 10 as an input unit, a marker extraction unit 12 as a marker signal extraction unit, a maximum value extraction unit 14 as a maximum value extraction unit,
Marker extraction condition changing unit 1 as extraction condition changing means
6 and a marker processing section 18 as a processing means.

The digital image input unit 10 receives a digital 8-bit image signal, for example, and sends the input image signal to the marker extraction unit 12, the local maximum value extraction unit 14, and the marker processing unit 18, respectively.

As shown in FIG. 2, the marker extraction unit 12 is composed of a high concentration side evaluation unit 20, a low concentration side evaluation unit 22, and a marker signal extraction unit 24. In the digital image signal input to the marker extraction unit 12, the high density portion and the low density portion are recognized as shown in FIG. 3, and the marker signal extraction unit 24 evaluates the continuity of the signal to obtain the marker signal. Is extracted. The extracted marker signal is sent to the marker extraction condition changing unit 16.

The maximum value extraction unit 14 is composed of the peripheral pixel reference unit 42 and the maximum value evaluation unit 43 shown in FIG. 4, and among the digital image signals input to the marker extraction unit 12, shown in FIG. As described above, when the pixel of interest has a local maximum value in any direction, the pixel is evaluated as the local maximum value.

The marker extraction condition changing unit 16 is composed of a maximum value continuity evaluating unit 62 and a marker recognition control unit 64 shown in FIG. 6, and the maximum value continuity evaluating unit 62 is
The continuity of maximum information obtained by the maximum value extraction unit 14 is evaluated. For example, the case where the maximum value continues for 10 pixels or more in any direction is evaluated as character information. The marker recognition control unit 64 does not perform extraction as a marker signal when the maximum value continuity from the maximum value continuity evaluation unit 62 is determined to be character information.

The marker processing section 18 responds to the digital image signal input from the digital image input section 10.
For example, erasing in the marker is performed.

The operation of the image processing apparatus of this embodiment will be briefly described below. First, in the digital image signal input to the digital image input unit 10, the marker extraction unit 12 detects the marker signal, and the maximum value extraction unit 14
Then, the maximum value of the digital image signal is extracted. further,
The marker extraction condition changing unit 16 evaluates the continuity of the extracted maximum value with respect to the surroundings. If the maximum value has continuity, it is not extracted as a marker signal, and the processed marker is processed as a marker.

FIG. 7 shows a block diagram of another embodiment of the image processing apparatus according to the present invention. In this embodiment, 2
This is an example of an image processing apparatus of a digital copier for color development, and mainly comprises a digital image input section 72, a marker extraction section 74, a maximum value extraction section 76, a marker extraction condition changing section 78, and a marker processing section 80. .

The digital image input unit 72 receives, for example, a digital 8-bit image signal and a 1-bit color signal corresponding to the image signal, and sends the input image signal to the marker extraction unit 74 and the marker processing unit 80, respectively.

The marker extraction unit 74, as shown in FIG. 8, includes a plurality of flip-flop circuits (FF) 8
2 and a first-in first-out memory circuit (FIFO) 84, and judges a color signal delayed by the FF and FIFO, and when all of the color signals are colors (marker colors), it is extracted as a marker signal, and the extracted marker The signal is sent to the maximum value extraction unit 76.

As shown in FIG. 4, the local maximum value extraction unit 76 is composed of a peripheral pixel reference unit 42 and a local maximum value evaluation unit 43, and among the digital image signals input to the marker extraction unit 74, As shown in FIG. 5, when the pixel of interest has a local maximum value in any direction, the pixel is evaluated as the local maximum value.

The marker extraction condition changing unit 78 is composed of a maximum value continuity evaluating unit 62 and a marker recognition control unit 64 shown in FIG. 6, and the maximum value continuity evaluating unit 62 is
The continuity of maximum information obtained by the maximum value extraction unit 14 is evaluated. For example, the case where the maximum value continues for 10 pixels or more in any direction is evaluated as character information. The marker recognition control unit 64 does not perform extraction as a marker signal when the maximum value continuity from the maximum value continuity evaluation unit 62 is determined to be character information.

The marker processing unit 80 responds to the digital image signal input from the digital image input unit 72 by
For example, erasing in the marker is performed.

The operation of the image processing apparatus of this embodiment will be briefly described. First, in the 8-bit digital image signal and the 1-bit color signal input to the digital image input unit 72, the marker extraction unit 74 detects the marker signal from the continuity of the color signal, and the maximum value extraction unit 76 detects the digital image signal. The maximum value is extracted, and further, the marker extraction condition changing unit 78 evaluates the continuity of the extracted maximum value with respect to the surroundings. If the maximum value has continuity, it is not extracted as a marker signal, and the Marker processing is performed on the marker.

In this embodiment, an example in which the image processing apparatus of the present invention is used in a digital copying machine is shown, but it is also possible to apply it to other apparatuses other than the digital copying machine such as a real-time image processing apparatus. Is.

[0022]

As is apparent from the above description, according to the image processing apparatus of the present invention, since the optimum marker detection is performed based on the continuity of the maximum value of the character image signal, a character having a low contrast is displayed. Marker processing can be performed on a mixed document without erroneous detection of markers.

Also in a two-color developing digital copying machine, since optimum marker detection is performed based on the continuity of maximum values of character image signals and the like, a color designated by the operator and the same color character are mixed. It is possible to perform marker processing on a document to be printed without erroneous marker detection.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an image processing apparatus of the present invention.

FIG. 2 is a configuration diagram of a marker extraction unit 12 of the embodiment of FIG.

FIG. 3 is a signal waveform diagram for explaining a marker extraction operation of the marker extraction unit 12 of the embodiment shown in FIG.

FIG. 4 is a configuration diagram of local maximum value extraction units 14 and 76 of the embodiments of FIGS. 1 and 7.

FIG. 5 is a diagram for explaining the operation of local maximum value extraction units 14 and 76 in the embodiments of FIGS. 1 and 7.

6 is a configuration diagram of marker extraction condition changing units 16 and 78 of the embodiments of FIGS. 1 and 7. FIG.

FIG. 7 is a configuration diagram showing another embodiment of the image processing apparatus of the present invention.

FIG. 8 is a configuration diagram of a marker extraction unit 74 of the embodiment of FIG.

FIG. 9 is a signal waveform diagram illustrating a marker detection operation of a conventional image processing apparatus.

FIG. 10 is a signal waveform diagram for explaining another example of the marker detection operation of the conventional image processing apparatus.

[Explanation of symbols]

 10, 72 Digital image input section 12, 74 Marker extraction section 14, 76 Maximum value extraction section 16, 78 Marker extraction condition changing section 18, 80 Marker processing section 20 High density side evaluation section 22 Low density side evaluation section 24 Marker signal extraction Part 42 Peripheral pixel reference part 44 Maximum value evaluation part 62 Maximum value continuity evaluation part 64 Marker recognition control part 82 Flip-flop circuit (FF) 84 First-in first-out memory circuit (FIFO)

Claims (2)

[Claims] 1. Input means for inputting a digital image signal, marker signal extracting means for extracting a marker signal from the digital image signal input to the input means, and the digital image signal input to the input means Local maximum value extraction means for extracting the local maximum values for the surrounding pixels, and extraction for changing the extraction condition of the marker signal from the marker signal extracted by the marker signal extraction means and the information of the maximum value extracted by the local maximum value extraction means. An image processing apparatus comprising: condition changing means and processing means for processing the digital image signal input to the input means by the marker signal obtained by the extraction condition changing means. 2. Input means for inputting digital image signals of at least two colors, marker signal extraction means for extracting a marker signal from the digital image signals input to the input means, and input to the input means. Maximum value extraction means for extracting the maximum value of the surrounding pixels of the digital image signal, marker signal extraction conditions by the marker signal extracted by the marker signal extraction means and the maximum value information extracted by the maximum value extraction means An image processing apparatus comprising: an extraction condition changing means for changing the above-mentioned condition; and a processing means for processing the digital image signal input to the input means by the marker signal obtained by the extraction condition changing means. .