JP2003060902A - Image processor, image processing method, image processing program and computer-readable recording medium with the program recorded - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processor that applies magnification processing to image data of an original and can output the image data, without deteriorating the productivity at a small magnification and without deteriorating the image quality at a high magnification. SOLUTION: A scanner 1 converts the image data of the original into vector data, when the set magnification is a prescribed magnification or over, converts the vector data again into vector data to obtain magnified image data, or magnifies the image data of the original through image interpolation to obtain magnified image data, when the magnification is smaller than the prescribed magnification.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing device. More specifically, it is an image processing apparatus capable of performing a scaling process on original image data and outputting the image data without lowering the productivity at a low scaling factor and the image quality at a high scaling factor.

[0002]

2. Description of the Related Art In recent years, the number of inkjet printers using roll paper has increased, and among them, there is also a large-format printing printer capable of printing up to A0 size. On the other hand, since the document size that can be read by an image reading device such as a scanner is up to about A3 size, when the image data read by the scanner or the like is transmitted to a large-format printing printer for printing, the document image data is Need to be expanded electrically or optically. For example, A with a scanner
To read 4 originals and print them in A0 size with a printer, it is necessary to enlarge them to 4 times (16 times in area), and such a high scaling factor is optically impossible, so image interpolation is exclusively performed. Image processing is being performed.

However, in the above example, the print image data is 150 even if the original image data is 600 dpi.
Since it is equivalent to dpi, the image roughness becomes conspicuous with a simple interpolation method such as the nearest neighbor method.
Even if an enlargement method such as a bilinear method or a bicubic method is used, there is a problem that an image is blurred in details.

On the other hand, there has been proposed a method in which original image data (raster data) is once converted into vector data, enlargement processing is performed, and the raster data is restored again after the processing. According to this method, the image does not become rough even if it is enlarged with a high scaling factor, but the processing content becomes more complicated than the image interpolation, so that the load on the CPU is large, and the processing time is rather long at a low scaling factor. Was becoming a problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art. The object of the present invention is to reduce the image quality at a high zoom ratio without lowering the productivity at a low zoom ratio. An object of the present invention is to provide an image processing apparatus that can perform scaling processing on original image data and output the image data without reducing the original image data.

[0006]

The above objects of the present invention can be achieved by the following means.

(A) When the set scaling ratio is equal to or larger than a predetermined scaling ratio, the first scaling process is performed by converting the original image data into vector data and reconverting it into raster data after scaling. First image data scaling means for obtaining scaled image data, and second scaling processing for scaling the original image data by image interpolation when the scaling ratio is less than the predetermined scaling ratio. And a second image data scaling means for obtaining the scaled image data of.

(B) further comprising a scaling processing time estimating means for estimating a scaling processing time required to perform the first scaling processing when the scaling ratio is equal to or larger than the predetermined scaling ratio. The image data scaling means No. 1 obtains the first scaled image data by performing the first scaling process when the scaling process time is less than a predetermined time. The image data scaling means further obtains the second scaled image data by performing the second scaling processing when the scaling processing time is equal to or longer than the predetermined time.
The image processing device according to (a).

(C) The image processing apparatus according to (a) or (b), further including a document reading unit for reading a document to obtain the document image data.

(D) The image processing apparatus according to any one of (a) to (c), further including scaling ratio setting means for receiving an input of the scaling ratio setting.

(E) In any one of (a) to (d), further comprising image data transmitting means for transmitting the first scaled image data or the second scaled image data to another device. The image processing device described.

(F) The image processing according to any one of (a) to (e), further including an image forming means for forming an image of the first scaled image data or the second scaled image data. apparatus.

(G) When the set scaling ratio is equal to or larger than a predetermined scaling ratio, the first scaling process is performed to convert the original image data into vector data and reconvert it into raster data after scaling. The step (1) of obtaining the scaled image data, and the second scale processing for scaling the original image data by image interpolation when the scale ratio is less than the predetermined scale ratio are used to perform a second scale processing.
And (2) obtaining variable-magnification image data in step (2).

(H) The method further comprises a step (3) of estimating a scaling process time required to perform the first scaling process when the scaling ratio is equal to or larger than the predetermined scaling ratio.
Is for performing the first scaling process to obtain the first scaled image data when the scaling process time is less than a predetermined time, and the step (2) further includes the scaling process. When the time is the predetermined time or more, the second scaling processing is performed to obtain the second scaled image data.
The image processing method according to (g).

(I) When the set scaling ratio is equal to or larger than a predetermined scaling ratio, the first scaling process is performed in which the original image data is converted into vector data and reconverted into raster data after scaling. The procedure (1) for obtaining the scaled image data and the second scaling process for scaling the original image data by image interpolation when the scaling ratio is less than the predetermined scaling ratio are performed.
An image processing program for causing an image processing apparatus to execute the procedure (2) of obtaining the scaled image data of 1.

(J) A computer-readable recording medium in which the image processing program described in (i) is recorded.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of an image processing system including an image processing apparatus according to the first embodiment of the present invention. The image processing system includes a scanner 1a as an image processing apparatus and printers 2a and 2b as image transmission destinations, which are communicably connected to each other via a communication network 3. The type and the number of devices connected to the communication network are not limited to the example shown in FIG.

FIG. 2 shows a scanner 1a according to this embodiment.
3 is a block diagram showing the configuration of FIG. In FIG. 2, the scanner 1a includes a CPU 11, a ROM 12, a RAM 13, a hard disk 14, an operation panel unit 15, an original reading unit 16,
Image interpolator 17, and network interface 1
8 are connected to each other via a bus 19 for exchanging signals.

The CPU 11 controls each of the above parts according to a program, vector conversion of document image data described later,
It performs scaling processing of vector data, raster conversion after scaling processing, and other various arithmetic processing. The ROM 12 stores various built-in programs and parameters. RAM13
Temporarily stores programs and data as a work area. The hard disk 14 is used to store various programs and parameters, or to temporarily store read original image data, image data after scaling processing, and the like.

The operation panel unit 15 includes a touch panel for displaying various information and setting input of various parameters, a start key for instructing the start of operation, and the like.

The document reading section 16 irradiates a document set at a predetermined reading position with light from a light source such as a fluorescent lamp, photoelectrically converts the reflected light into a light receiving element such as a CCD or CIS, and converts the electric signal from the electric signal. Image data (bitmap data) is generated. The document reading unit 16 may include an automatic document feeder (ADF), and in this case, a plurality of documents can be conveyed one by one to a predetermined reading position by the ADF and sequentially read.

The image interpolating unit 17 performs a scaling process on the original image data acquired as described later by image interpolation.

The network interface 18 is an interface for connecting to the network and communicating with other devices on the network, and standards such as Ethernet (registered trademark), token ring, and FDDI are used.

When the scanner 1a is connected to the communication network 3, the scanner 1a receives an original reading command from the operation panel unit 15 and a reading command from another device on the network, and reads image data obtained by reading the original. Has a function of transmitting a message to a device on a specified network.

The printers 2a and 3 are connected to the communication network 3, receive print jobs from other devices on the network, and print out print images (bitmap data). The printer 2a can print on A0 size paper, and the printer 2b can print on A3 size paper.

The communication network 3 is a telephone network, a mobile communication network, an ISDN, a public network such as a packet switching network, and an LA.
It includes computer networks such as N, WAN, and the Internet.

Next, the outline of the operation of the image processing apparatus according to this embodiment will be described. FIG. 3 is a flowchart showing a procedure of image processing of the scanner 1a in this embodiment. In FIG. 3, the scanner 1a waits until input of settings such as printing conditions is input (NO in S101). The user uses the operation panel unit 15 to output the destination printer, the number of prints, the paper size, the magnification, the density, and the layout (the function of arranging N pages of data into one page of output data (N
in 1) etc.) and the document reading conditions such as image size and resolution are input. It should be noted that setting of printing conditions and the like, and input of a document reading command to be described later may be performed from another device on the communication network 3. In this case, the scanner 1a uses the communication network 3 and the network interface 18 to print the printing conditions and the like. Receives the original reading command. Further, when there is an original reading command without setting the printing conditions and the like, the initial conditions stored in advance in the ROM 12 or the hard disk 14 are set as the printing conditions and the like.

When the scanner 1a receives the input of the setting of the printing condition and the like (YES in S101), it waits until a document reading command is issued (NO in S102).
The user sets a document on a document table at a predetermined position and presses the start key of the operation panel unit 15. When the scanner 1a receives the original reading command, the scanner 1a reads the original according to the setting conditions and acquires image data (S103). The obtained original image data is temporarily stored in the hard disk 14.

Then, if the scaling factor is set to a value other than the equal size which is the initial condition in the procedure for receiving the setting input of the printing conditions (S101) (YES in S104), the scaling factor set for the original image data is set. Magnification processing according to is performed. That is, the scaling factor set in step S101 is R
If the magnification is equal to or larger than the predetermined magnification stored in the OM 12 or the hard disk 14 (YES in S105), the original image data that is raster data is converted into vector data (raster-data).
Vector conversion) (S106), the obtained original image data of the vector data is subjected to the scaling processing (S107), and the original image data of the vector data after the scaling processing is reconverted into raster data (vector-raster conversion). Then, the scaled image data is created (S108). On the other hand, step S101
If the scaling ratio set in step S4 is less than the predetermined scaling ratio (NO in S105), scaling processing by image interpolation is performed on the original image data to create scaled image data (S1).
09). The obtained scaled image data is stored in the hard disk 14
Temporarily store in.

As shown in FIG. 4, original image data (see FIG.
When the enlargement / reduction processing of (a)) is performed by a method based on image interpolation (bicubic method) (FIGS. 4B and 4C) and when it is converted to vector data (FIG. 4).
Comparing (d) and (e) with each other, there is no great difference between the two at low magnifications up to about 2 (Fig. 4 (b)).
And (d)), at higher magnifications, the vector conversion method causes no change, whereas the image interpolation method makes image roughness and blurring noticeable (FIGS. 4C and 4E). )). Therefore, as the predetermined scaling factor, a scaling factor (for example, a scaling factor of 2 times, but not limited to this) is set as a limit at which image roughness or blurring becomes noticeable in the scaling process by image interpolation. By this, when image data is output to a large format printer such as the printer 2a, the original image data is converted into vector data and scaled in a high enlargement / magnification area, so that image roughness or blurring occurs. Therefore, the enlarged image data can be output without degrading the image quality. On the other hand, in the case of outputting image data to a normal-size printing printer such as the printer 2b, in the low enlargement / reduction area, the image roughness or Since deterioration of image quality such as blurring is not noticeable, processing time can be shortened by performing scaling processing by simple image interpolation instead of complicated processing such as scaling processing by the above vector conversion, thus improving productivity. It is possible to output the scaled image data without reducing

Well-known methods can be used as the raster-vector conversion and vector-raster conversion methods executed in the procedure (S106 to S108) of the scaling processing by the vector conversion described above. Further, as the image interpolation method used in the scaling processing procedure (S109) described above, a well-known method such as a bilinear method or a bicubic method can be adopted. In the scaling processing procedure by vector conversion (S106 to S108), when the original image data includes an image area (for example, a photograph area) that cannot be converted into vector data, only the area is raster-vectored. The raster data is left as it is without conversion, and the area is subjected to scaling processing by image interpolation.

Then, the procedure of the above-mentioned scaling processing (S106-).
Image processing such as CMYK conversion, moiré removal in the photographic image area, contrast adjustment, and saturation adjustment is performed on the scaled image data obtained in S108 or S109 (S11).
0), temporarily store the obtained output image data in the hard disk 14. Then, the output image data, together with the necessary printing conditions, is sent as a print job to the designated printer via the network interface 18 and the communication network 3 (S111). PD print job
When transmitting to the printer by L, step S110
The image data obtained in the above is converted into PDL and transmitted to the printer.

On the other hand, when the scaling factor is set to the same condition as the initial condition in step S101 (NO in S104),
Only the image processing of step S110 is performed on the original image data without performing the scaling processing, and the obtained output image data is transmitted to the designated printer together with the necessary printing conditions (S110 and S111).

FIG. 5 is a flow chart showing the procedure of image processing of the scanner 1b according to the second embodiment of the present invention. The scanner 1b of the present embodiment has the same configuration as the scanner 1a according to the first embodiment, and like the scanner 1a, the printer 2a via the communication network 3.
And the printer 2b so that they can communicate with each other.

The image processing procedure of the scanner 1b according to the present embodiment is different from the image processing procedure of the scanner 1a according to the first embodiment, firstly, the procedure for receiving a setting input such as printing conditions (S201). If the scaling ratio set in step S4 is greater than or equal to the predetermined scaling factor (YES in S205), the processing time required for the scaling process by vector conversion (S208 to S210) is estimated. That is, the time required for the raster-vector conversion of the original image data, the scaling processing of the vector data, and the vector-raster conversion after the scaling processing is estimated, and the scaling processing time is calculated by summing these (S206). When the estimated scaling processing time is less than the predetermined time (YES in S207), the scaling processing by vector conversion (S208 to S210) is performed, and when the estimated scaling processing time is the predetermined time or more (S207). N
O), the scaling processing by image interpolation (S211) is performed. Depending on the original image data, the scaling process by vector conversion may take a long time.In such a case, it is more realistic to use the scaling process by image interpolation even if the set scaling factor is equal to or higher than a predetermined scaling factor. Therefore, when the set magnification is equal to or higher than the predetermined magnification, the scaling processing time by vector conversion is estimated in advance so that the relationship between the image quality and the processing speed can be adjusted more specifically.

In the above embodiment, the method of scaling the image data is automatically switched between the vector conversion method and the image interpolation method by using the predetermined scaling rate as a threshold. When setting the printing conditions, etc., two modes, speed priority and image quality priority, can be set. When the speed priority mode is set, the scaling processing by image interpolation is performed even if the magnification is a predetermined magnification or more, and the image quality priority mode is set. When is set, the scaling process may be performed by vector conversion even if the scaling factor is less than the predetermined scaling factor.

In each of the above embodiments, the image processing apparatus according to the present invention has been described by taking the scanner as an example, but the present invention is not limited to this. For example, an image processing apparatus such as a personal computer may be used to execute the procedure of scaling processing (S104 to S111 or S204 to S213) in each of the above-described embodiments, and may be configured as an image processing system combined with a scanner and a printer. It may be configured as a multi-function peripheral device (MFP) having a printing function such as a digital copying machine by forming an image of output image data after the double processing.

The image processing apparatus and the image processing method according to the present invention may be implemented by a dedicated hardware circuit for executing each of the above procedures, or by a CPU executing a predetermined program describing each of the above procedures. Can be realized. When the present invention is realized by the latter, the predetermined program for operating the image processing apparatus may be provided by a computer-readable recording medium such as a floppy (registered trademark) disk or a CD-ROM,
It may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is usually transferred to and stored in a ROM, a hard disk, or the like. Further, this program may be provided as, for example, independent application software, or may be incorporated into the software of the image processing apparatus as one function.

The embodiments of the present invention described above include the inventions as shown in the following supplementary notes 1-10 in addition to the inventions as set forth in claims 1-10 of the claims.

[Supplementary Note 1] The image processing method according to claim 7 or 8, further comprising a step (4) of reading a document to obtain the document image data.

[Supplementary Note 2] The method according to claim 7 or 8, further comprising a step (5) of receiving an input of the setting of the scaling factor.
Alternatively, the image processing method according to attachment 1.

[Supplementary Note 3] The method according to Claim 7 or 8 or Supplementary Note 1 or 2, further comprising a step (6) of transmitting the first scaled image data or the second scaled image data to another device. Image processing method.

[Supplementary Note 4] The method according to Claim 7 or 8 or Supplementary Note 1 further comprising a step (7) of forming an image of the first scaled image data or the second scaled image data.
The image processing method according to any one of 1 to 3.

[Supplementary Note 5] The image processing apparatus is further caused to execute the procedure (3) of estimating the scaling processing time required to perform the first scaling processing when the scaling ratio is equal to or larger than the predetermined scaling ratio. The procedure (1) is to obtain the first scaled image data by performing the first scaling process when the scaling process time is less than a predetermined time. 10. The image processing according to claim 9, wherein) further obtains the second scaled image data by performing the second scaling process when the scaling process time is equal to or longer than the predetermined time. program.

[Supplementary Note 6] The image processing program according to Claim 9 or Supplementary Note 5, further causing the image processing apparatus to execute the procedure (4) of reading a document and obtaining the document image data.

[Supplementary Note 7] The image processing program according to Claim 9 or Supplementary Note 5 or 6, further causing the image processing apparatus to execute the step (5) of accepting the input of the setting of the scaling factor.

[Supplementary Note 8] The image processing apparatus is caused to further execute the step (6) of transmitting the first scaled image data or the second scaled image data to another device. The image processing program according to any one of appendices 5 to 7.

[Supplementary Note 9] The procedure (7) of forming an image of the first scaled image data or the second scaled image data is further executed by the image processing apparatus. 8. The image processing program according to any one of 8.

[Supplementary Note 10] A computer-readable recording medium recording the image processing program according to Supplementary Notes 5 to 9.

[0051]

As described above, according to the image processing apparatus of the present invention, the method of scaling processing of image data is automatically performed by the vector conversion and the image interpolation by using a predetermined scaling factor as a threshold. Since switching is performed, in the high enlargement / reduction area, enlarged image data can be output without image roughness and blurring due to the enlargement / reduction processing by vector conversion. In the area, by performing the scaling process by the simple image interpolation, it is possible to shorten the processing time and output the scaled image data without lowering the productivity.

Further, according to the image processing apparatus of the present invention, when the set magnification is equal to or larger than the predetermined magnification, the scaling processing time by the vector conversion is estimated in advance, so that the scaling processing by the vector conversion takes a long time. In such a case, the relationship between the image quality and the processing speed can be adjusted more specifically by adopting the scaling processing by image interpolation even if the set magnification is equal to or higher than the predetermined magnification.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of an image processing system including an image processing apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a scanner 1a in FIG.

FIG. 3 is a flowchart showing a procedure of image processing of the scanner 1a in FIG.

FIG. 4 is a diagram showing a comparison between original image data subjected to scaling processing by a method based on image interpolation and that subjected to scaling processing based on a method based on vector conversion.

FIG. 5 is a scanner 1 according to a second embodiment of the present invention.
It is a flowchart which shows the procedure of the image processing of b.

[Explanation of symbols]

1a, 1b ... Scanner, 11 ... CPU, 12 ... ROM, 13 ... RAM, 14 ... Hard disk, 15 ... Operation panel section, 16 ... Image reading unit, 17 ... Image interpolation unit, 18 ... Network interface, 19 ... bus, 2a, 2b ... Printer, 3 ... Communication network.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G06T 3/40 B41J 3/12 GF term (reference) 2C062 AA24 AA52 2C087 AA18 AC07 BA02 BA03 BB10 BD06 BD24 5B021 AA01 BB01 BB02 LB07 5B057 AA11 BA02 BA26 CD05 CD06 CH01 CH18 5C076 AA21 BA05 BB25 BB40 CB01

Claims (10)

[Claims] 1. When the set scaling ratio is equal to or greater than a predetermined scaling ratio, the first scaling process is performed to convert the original image data into vector data and reconvert it into raster data after scaling.
First image data scaling means for obtaining the scaled image data, and second scaling processing for scaling the original image data by image interpolation when the scaling ratio is less than the predetermined scaling ratio. An image processing device, comprising: a second image data scaling unit that obtains two scaled image data. 2. A scaling processing time estimating means for estimating a scaling processing time required to perform the first scaling processing when the scaling ratio is equal to or larger than the predetermined scaling ratio. Image data scaling means is for obtaining the first scaled image data by performing the first scaling process when the scaling process time is less than a predetermined time. 3. The data scaling means further obtains the second scaled image data by performing the second scaling process when the scaling process time is equal to or longer than the predetermined time. Image processing device. 3. The image processing apparatus according to claim 1, further comprising a document reading unit that reads a document to obtain the document image data. 4. The scaling factor setting means for accepting an input of the scaling factor setting.
The image processing device according to item. 5. The image according to any one of claims 1 to 4, further comprising image data transmitting means for transmitting the first scaled image data or the second scaled image data to another device. Processing equipment. 6. The image processing apparatus according to claim 1, further comprising an image forming unit that forms an image of the first scaled image data or the second scaled image data. 7. When the set scaling ratio is equal to or larger than a predetermined scaling ratio, the first scaling process is performed to convert the original image data into vector data and reconvert it into raster data after scaling.
Step (1) of obtaining the scaled image data of step (1), and performing a second scaling process of scaling the original image data by image interpolation when the scale factor is less than the predetermined scale factor. An image processing method comprising: (2) obtaining image data. 8. The method further comprises a step (3) of estimating a scaling process time required to perform the first scaling process when the scaling ratio is equal to or larger than the predetermined scaling ratio. A step of performing the first scaling processing to obtain the first scaled image data when the scaling processing time is less than a predetermined time, and the step (2) further includes the scaling processing time. Is greater than or equal to the predetermined time, the second scaling process is performed to perform the second
The image processing method according to claim 7, wherein the scaled image data is obtained. 9. When the set scaling ratio is equal to or greater than a predetermined scaling ratio, the first scaling process is performed to convert the original image data into vector data and reconvert it into raster data after scaling.
(1) for obtaining the scaled image data of No. 2 and a second scaling process for performing a second scaling process for scaling the original image data by image interpolation when the scaling ratio is less than the predetermined scaling factor. An image processing program for causing an image processing apparatus to execute the procedure (2) of obtaining image data. 10. A computer-readable recording medium in which the image processing program according to claim 9 is recorded.