JPH03258166A - Scanner system - Google Patents

Abstract

PURPOSE:To obtain a print use dot picture data at fast speed with high accuracy by generating simultaneously a transmittivity file for picture display for setup and a density file for generating a print use dot picture data through one scanning by means of a flat bed scanning scanner. CONSTITUTION:An original having magnification, angular trimming information in advance is scanned by a flat bed scanner 1 and two digital data, transmittivity data and density data are simultaneously outputted each time one line is read. Then the transmittivity of the original is converted into an electric signal by a CCD 11, A/D-converted by an A/D converter 12, from which the transmittivity data is obtained, and the other data is subject to logarithmic transformation by a logarithmic transformation circuit 13, A/D-converted by an A/D converter 14, from which the density data is obtained. The transmittivity data obtained by the scanner 1 is set in a frame memory 2 as a picture display file and the density data is set in the memory 2 as an original data file respectively simultaneously. Thus, the print use dot picture data is obtained at fast speed with high accuracy.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to image input using a flat scanning scanner that inputs image information of a document set on a document table by scanning a reading head section in a flat surface. In particular, the present invention relates to a scanner system that can efficiently obtain high-quality printing halftone image data without much effort.

(Prior Art) Conventionally, for example, a drum-type scanner with a rotating drum has been widely used as a human-powered device such as a layout scanner system that can efficiently output images by arranging a plurality of images onto a single film. ing. On the other hand, recently, due to their high quality, high definition, and cost, plane scanning scanners, such as flatbed scanners, are being used instead. This flatbed type scanner inputs image information of a color document set on a document table by performing flat scanning with a reading head. Recently, improvements in the performance of charge-coupled devices (hereinafter referred to as CCDs) have made it possible to obtain considerably high-quality images for printing using flatbed scanners equipped with CCDs.

By the way, when disassembling a document that already has magnification, angle, and trimming information using a flatbed scanner equipped with this type of CCD, the setup process involves identifying highlight points and shadow points on the document. It is necessary to set the percentage of the net to be inserted at that concentration. In this case, the following two methods are currently being used.

(1) A method of hitting the original with an fR meter, looking for highlight points and shadow points, and measuring their density.

(2) A method of performing a set-up scan (hereinafter referred to as pre-scan) to manually create a rough image, and then determining the positions and densities of highlight points and shadow points from that data.

(Problems to be Solved by the Invention) However, these conventional methods each have the following problems. In the former method, (a) there is a high possibility that the density determined with a densitometer will be different from the density obtained using a flatbed scanner; (b) if the document size is small, There is a problem in that it takes time and effort to find highlight points and shadow points.

In addition, in the latter method, (a) it takes a very long time because the document must be scanned twice, pre-scanning and main scanning, and (b) digital data with quantized transmittance is output.
In the case of a flatbed scanner equipped with a CD, linear transmittance data must be converted to density by a computer, and the calculation of converting transmittance to density is non-linear, making it difficult to obtain highly accurate density data. The problem is that it cannot be done.

In either method, in addition to the main scan, a pre-scan for setup must be performed or the document must be scanned with a densitometer, which is very time-consuming.

Therefore, in recent years, a method has been proposed in which the image data obtained from a flatbed scanner equipped with a CCD is converted into density values in the process of converting the image data obtained from a flatbed scanner to halftone image data for printing. It has been done. However, in the case of a scanner that outputs digital transmittance data, using this method, it takes time to convert it to density values using a computer, and since the conversion is nonlinear, the data accuracy is poor, making it difficult to use for high-quality printing. There is a problem that halftone image data cannot be obtained.

The present invention was developed to solve the above-mentioned problems, and provides a highly reliable scanner system that can extremely efficiently obtain high-quality printing halftone image data without much effort. The purpose is to provide.

(Means for Solving the Problems) In order to achieve the above object, the present invention uses a CCD that converts the transmittance of a document into an electrical signal, converts the electrical signal from the CCD into an analog/digital converter, and outputs transmittance data. At the same time, we are using a flat scanning scanner consisting of a conversion circuit that logarithmically converts electrical signals and analog/digital conversion to output density data, and transmittance data from the flat scanning scanner for image display and density data. a storage means for storing the file as a file for creating halftone image data for printing; an image display means; searching for highlight points and shadow points from the density data file in the storage means and displaying their density values on the image display means; an image processing means having a set-up function for setting conditions for what percentage of dots to be applied, and an image data creation function for creating halftone image data for printing from a density data file in a storage means based on the set-up conditions; It is configured with the following.

(Function) Therefore, in the scanner system of the present invention, a transmittance file for image display for setup and a density file for creating halftone image data for printing can be created in one scan by a plane scanning type scanner. are created at the same time, and then set-up work is performed to create halftone image data for printing from the density value file. As a result, the density data required for conversion to halftone image data for printing can be obtained quickly and with high accuracy using a plane scanning scanner, making it possible to create halftone image data for printing efficiently and with high accuracy. You can get quality products. Furthermore, since there is no need to perform pre-scanning or the like for setup, work can be carried out extremely efficiently.

(Example) The present invention performs setup after scanning image data for creating halftone image data for printing, and uses image processing means to create a file of density values already created on storage means under the setup conditions. This process efficiently creates high-quality printing halftone image data.

Hereinafter, an embodiment of the present invention based on the above concept will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an example of the configuration of a scanner system according to the present invention. The scanner system of this embodiment includes a flatbed type scanner 1 which is a plane scanning type scanner, a frame memory 2, a storage device 3, a computer 4 which is an image processing means, and a display for image display which is an image displaying means. It consists of 5.

Here, as shown in a detailed block diagram in FIG. 2, the flatbed scanner 1 includes a CCD 11 and an analog/digital conversion circuit (hereinafter referred to as an A/D conversion circuit).
12, a logarithm (log) conversion circuit 13, and an A/D conversion circuit 14. The CCD 11 converts the transmittance of a document, which has magnification, angle, and trimming information in advance, into an electrical signal. The A/D conversion circuit 12 performs A/D conversion on the electrical signal from the CCD II and outputs transmittance data. Further, the logarithmic conversion circuit 13 performs logarithmic conversion of the electrical signal from the CCDI 1. The A/D conversion circuit 14 performs A/D conversion on the output signal from the logarithmic conversion circuit 13 and outputs density data.

On the other hand, the frame memory 2 stores transmittance data output from the flatbed scanner 1 in a file format for image display. In addition, storage device 3
The density data output from the flatbed scanner 1 is stored as a file for creating halftone image data for printing. Furthermore, the computer 4 has a set-up function that searches for highlight points and shadow points from the density data file in the storage device 3, displays their positions and density values on the display 5, and sets conditions for adding 4n1% dots. , and an image data creation function for creating printing halftone image data from the density data file in the storage device 3 based on the set-up conditions.

Next, the operation of the scanner system configured as described above will be explained using the flow diagram shown in FIG.

In Figure 1, a document with magnification, angle, and trimming information is scanned by a flatbed scanner 1, and each time one line is read, two digital data, transmittance data and density data, are output simultaneously. Ru. That is, the transmittance of the original is converted into an electric signal by the CCD 11, one is A/D converted by the A/D conversion circuit 12 to obtain transmittance data, and the other is logarithmically converted by the logarithmic conversion circuit 13. (If transmittance is T, concentration -1og+o
(obtained as l/T), and further A/D converted by the A/D conversion circuit 14 to obtain density data.

On the other hand, the transmittance data thus obtained by the flatbed scanner 1 is stored in the frame memory 2 for image display, and the density data is stored in the storage device as original data for creating halftone image data for printing. 3, files are created for each. Next, the computer 4 searches for highlight points and shadow points from the density data file in the storage device 3, and determines their positions.
The density value is displayed on the display 5, and conditions such as setting up the percentage of mesh to be inserted are performed. Further, when a certain point on the image on the display 5 is hit, the density value at that position is read out from the density data file and displayed. Next, when the setup is completed in this way, the density data for creating printing halftone image data that has already been created on the storage device 3 is processed based on the setting conditions, and the density data for printing halftone image data is processed. Image data is created.

As described above, the scanner system of this embodiment uses CCD II and CCD1 that convert the transmittance of the document into electrical signals.
A/D conversion circuit 12 converts the electrical signal from the CCD II into a logarithm and outputs transmittance data, a logarithmic conversion circuit 13 converts the electrical signal from the CCDII into a logarithm, and converts the output signal from the logarithmic conversion circuit 13 into A/D. A/D converts and outputs density data
Flatbed scanner consisting of D conversion circuit 14]
, a frame memory 2 that stores transmittance data from the flatbed scanner 1 as a file for image display, a storage device 3 that stores density data as a file for creating halftone image data for printing, and a display. 5, a set-up function that searches for highlight points and shadow points from the density data file in the storage device 3, displays their density values on the display 5, and sets conditions for what percentage of dots are added; The computer 4 has an image data creation function for creating halftone dot image data for printing from the density data file in the storage device 3 based on the above.

Therefore, the flatbed scanner 1 performs only the main scan on a document that has the magnification, angle, and trimming information without prescanning it.
Thereafter, the computer 4 can perform setup and conversion into halftone dot image data for printing, making it possible to perform the work much more efficiently than in the past.

In addition, the density data necessary to create halftone image data for printing can be obtained quickly and with high precision using the analog circuitry within the flatbed scanner 1, resulting in efficient creation of halftone image data for printing. This makes it possible to obtain high-quality products. Furthermore, since there is no need to perform pre-scanning or the like for setup, it is possible to work extremely efficiently.

In the above embodiment, a case has been described in which a file of transmittance data outputted from the flatbed scanner 1 is created on the frame memory 2, but the present invention is not limited to this. You may also create one.

(Effects of the Invention) As described above, according to the present invention, it is possible to provide a highly reliable scanner system that can extremely efficiently obtain high-quality printing halftone image data without much effort.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a scanner system according to the present invention, and FIG. 2 is a block diagram showing an example of the internal circuit configuration of a flatbed type scanner in the same embodiment.
FIG. 3 is a flow diagram for explaining the operation in the same embodiment. 1...Flatbed type scanner 2...Frame memory, 3...Storage device, 4...Computer, 5
...Display, 11...CCD, 12...A
/D conversion circuit, 13...logarithm (log) conversion circuit, 1
4...A/D conversion circuit.

Claims (1)

[Claims] A CCD that converts the transmittance of a document into an electrical signal, the CCD
a flat scanning scanner comprising a conversion circuit that converts an electric signal from analog to digital to output transmittance data, and at the same time logarithmically converts the electric signal and converts it from analog to digital to output density data; a storage means for storing transmittance data from the scanning scanner as a file for image display and density data for creating halftone image data for printing; an image display means; A setup function that searches for light points and shadow points, displays their density values on the image display means, and sets conditions for determining what percentage of mesh is to be added; 1. A scanner system comprising: an image processing means having an image data creation function for creating halftone image data for printing;