JPH02277661A - Image processing method - Google Patents

Abstract

PURPOSE:To enlarge an image even with a large magnification ratio at high speeds by a method whereby an answer of the factorization of a set magnification factor is determined among the magnification factors, and an enlarging process corresponding to the magnification factor is read out from a memory means, so that an image data is subjected to the enlarging process. CONSTITUTION:A ROM 56 having a function as a memory means accommodates an enlargement table 56A which includes enlarging processes corresponding to a plurality of preliminarily-set different enlarging magnification factors, namely, bit pattern tables corresponding to the magnification ratios of twice, three times, five times and seven times. A CPU 51 reads out and executes the program for an enlarging process stored in a program memory 57 and determines an answer of the factorization of the set enlarging ratio (magnification factor). At the same time, the CPU 51 reads out from the ROM 56 and executes the enlarging process corresponding to the determined answer, thereby enlarging the image data.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image processing method that performs an enlargement process on image data according to a set magnification.

[Conventional technology]

Conventionally, workstations, computers, etc. that serve as image processing devices have generally been equipped with a function to perform enlargement/reduction processing on image data. There are several magnifications such as 2x, 4x, 6x, etc., and a routine for enlargement processing is provided corresponding to each magnification. When a predetermined enlargement magnification is set, such an image processing apparatus executes a corresponding enlargement processing routine to perform enlargement processing on image data.

For example, as shown in FIG. 12(a), when the image processing device performs a six-fold enlargement process on one line in the X direction of the image data corresponding to the alphanumeric character "F", b)
As shown in the figure, the 1-bit data of the 1st pixel is shifted 1 bit at a time and repeated until it becomes 6 bits to perform a 6x enlargement process, and the same enlargement process is applied to the 2nd and 3rd pixels.
This is also performed for each pixel, . . . . By performing such enlargement processing on all image data, the 12th
The image shown in Figure (a) will be enlarged six times.

[Problem to be solved by the invention]

By the way, in the above-mentioned conventional image processing device, the 1-bit data of each pixel is enlarged by shifting it 1 bit at a time until the number of bits corresponds to the desired magnification (for example, if the magnification is 6 times, the data becomes 6 bits). 1 bit at a time), and the processing speed of enlargement processing cannot necessarily be said to be high. In particular, there was a drawback that the higher the magnification, the lower the processing speed of the enlargement process.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image processing method that eliminates the above-mentioned drawbacks and can perform enlargement processing at high speed even at high magnification.

[Means to solve the problem]

The present invention provides a storage means for storing each enlargement processing procedure corresponding to a plurality of different enlargement factors set in advance, and a determining means for determining a solution of factorization of a predetermined enlargement factor from among the above-mentioned enlargement factors. and processing means for reading out from the storage means and executing an enlargement processing procedure corresponding to the enlargement magnification coefficient corresponding to the solution of the factorization determined by the determination means, and performing enlargement processing on the image data. It is.

[Effect]

In the present invention, for example, enlargement processing procedures corresponding to enlargement coefficients of 2 times, 3 times, 5 times, and 7 times are stored in the storage means.

For example, when a magnification factor (magnification factor) of 12 times is set, the determining means calculates the solution of the factorization of the magnification factor 12 from among the above-mentioned magnification factor factors (2, 3, 5, 7). In this case, a 3×2×2 combination is determined. The processing means reads from the storage means and executes an enlargement processing procedure corresponding to the enlargement magnification coefficient corresponding to the value of the solution of the determined 3X2X2 combination, and performs enlargement processing on the image data. During this enlargement process, the magnification coefficient is 12 (
When the enlargement magnification is 12 times), the processing means performs a 3 times enlargement process on the original image data, and then performs a 2 times enlargement process on the image data that has been subjected to the 3 times enlargement process. alms,
For image data that has been further enlarged by 2 times,
Performs double magnification processing. As a result, the original image data has finally been subjected to 12 times enlargement processing.

〔Example〕

Embodiments of the image processing method according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of an image printing apparatus to which an image processing method according to the present invention is applied.

In the figure, the image printing device includes an image supply device 11,
It has a recording section 12, a power source 13 for driving these, and a panel 14 through which an operator inputs recording operation instructions.

The image supply device 11 includes a host interface (hereinafter referred to as host ■/F) connection terminal 1 that receives a signal for recording a predetermined image from a host computer (not shown).
5 and the L that connects with the local area network, etc.
An AN connection terminal 16 is provided.

The recording unit 12 is a device that records an image corresponding to an image signal on a recording paper 17, and receives an image signal 18 and an operation command 19 from the image supply device 11, and also receives a synchronization pulse for recording operation. 20 and a status signal 21 are output to the image supply device 11.

AC power is supplied to the power supply 13 via a power supply terminal 22 .

FIG. 2 shows a perspective view of essential parts of the recording section 12 shown in FIG. 1. In FIG. 2, a laser beam 32 emitted from a laser generator 31 passes through a polarizer 33, a laser beam modulator 34, and a polarizer 35, is reflected by a polygon mirror 36, passes through a lens 37, and then passes through a photosensitive drum. It reaches the outer peripheral surface of 38.

The image signal 18 (pit stream) from the image supply device 11 in FIG.
The plane of polarization of the laser beam passing through the modulator 34 is manually rotated in accordance with the image signal by, for example, an electro-optic effect.

By this so-called electric shutter action, the black and white binary image signal is converted into an optical on/off signal of a laser beam, and the outer peripheral surface of the photosensitive drum 38 is irradiated with the optical on/off signal. The polygon mirror 36 is rotated at a constant speed by a motor 40, and after reflecting the laser beam 32, it is scanned in the direction of arrow A (this direction is referred to as main scanning). That is,
The photosensitive drum 38 rotates in the direction of arrow B (this direction is referred to as sub-scanning) while the image signal for one line is converted into an optical bit string and is irradiated in a direction parallel to the rotation axis 41 of the photosensitive drum 38. . In this way, an electrostatic latent image corresponding to the image to be recorded is formed on the outer peripheral surface of the photosensitive drum 38.

This electrostatic latent image passes through the developing device 42 as the photosensitive drum 38 rotates in the direction of arrow C. Here, toner is deposited in accordance with the electrostatic latent image. When the recording paper 17 is fed in the direction of arrow C by a recording conveyance mechanism (not shown), the toner attached to the outer peripheral surface of the photosensitive drum 38 is transferred onto the recording paper 17 by the action of the transfer device 43 . Recording paper 17
The recording material is further sent in the direction of arrow C and subjected to processing such as fixing to obtain a recorded matter.

Note that the laser beam 32 is scanned in the direction of arrow A with a width that exceeds both ends of the photosensitive drum 38.

Therefore, the transfer timing of the image signal 18 is determined by detection pulses that detect the passage of the laser beam from the scan start sensor 44 and the scan end sensor 45.

The specific configuration of the image supply device 11 shown in FIG.
Shown in the figure.

In FIG. 3, the image supply device 11 includes a CPU bus 50
It is composed of a microprocessor/source (hereinafter referred to as CPU) 51 connected to the CPU, various interface devices (hereinafter referred to as I/F) 52 to 54, memories 55 to 60, and control blocks 61 to 62. There is.

The interface includes a host I/F52 and a panel I/F52.
F53 and the recording department! /F54.

The host I/F 52 is a circuit that receives code data input from a host computer (not shown) in accordance with, for example, the R3232C standard. The panel I/F 53 is a circuit that relays the manual instruction signal 53a from the panel 14 operated by the operator. The recording unit I/F 54 transmits and receives signals (image signal 18, operation command 19, synchronization pulse 20,
This is a circuit that relays the status signal 21).

The memory includes a random access number memory (hereinafter referred to as RA).
55, a read-only memory (hereinafter referred to as ROM) 56, a program memory 57, a character pattern memory 58, a work memory 59, and a bitmap memory 60.

The RAM 55 stores various data for the operation of the CPU 51 and code data input from the host I/F 52.

The ROM 56, which has the function of a storage means, stores the expansion table 5.
6A, and this magnification table 56A stores magnification processing procedures corresponding to a plurality of different preset magnification coefficients, that is, magnifications corresponding to 2x, 3x, 5x, and 7x. Bit pattern tables are included, and each of these tables stores enlarged data of [8 bits x value of magnification coefficient]. For example, when it is 2 times,
Enlarged data of 8 bits x 2 to 16 bits is stored, or in the case of 3 times, enlarged data of 8 bits x 3 to 24 bits.

The program memory 57 stores a program for the operation of the CPU 51 and a program (enlargement processing program) based on a flowchart showing a processing procedure to be described later.

The character pattern memory 58 stores character patterns composed of a so-called dot matrix.

The enlarged image data is developed in the work memory 59.

The bitmap memory 60 is a circuit that stores, for example, one page of an image to be recorded on the recording paper 17 in the recording section 12 in a bitmap format.

As a control block, a bitmap controller 61
, a programmable timer counter (hereinafter referred to as PTC) 62, and a bitmap controller 61,
It controls the address timing and addresses to the bitmap memory, and controls the transfer of image data formed in the bitmap memory 60 to the recording unit I/F 54. The PTC 62 is a circuit that measures time and generates timing.

The CPU 51 has the function of a determining means and the function of a processing means, and reads out and executes the enlargement processing program stored in the program memory 57, and determines the factor of the set enlargement magnification (magnification coefficient). A solution for the decomposition is determined, and an enlargement processing procedure corresponding to the determined solution is executed to perform enlargement processing on the image data.

Further, among the components shown in FIG. 3, each component other than the bitmap controller 61 is connected to the CPU bus 50.

Next, the enlargement processing operation of the image printing apparatus will be explained based on the flowcharts of FIGS. 4 and 5.

As shown in FIG. 6, the process of enlarging an image in the X direction and the Y direction will be described. First, the process of enlarging the image in the X direction will be explained.

As shown in FIG. 4, the CPU 51 first calculates the coefficient mSn based on the received magnification factor (magnification factor).
The enlargement magnification is defined as -a (eg, a-12) (step 100), and Free-0, n-1 (step 1o1).

Then, the CPU 51 determines that the defined enlargement magnification a is "2".
If it is not a-2, it is determined whether the enlargement magnification a is "3" or not (step 103). If it is not a-3, then the enlargement magnification a is is "5" or not (Step 104)
, a-5, it is further determined whether the enlargement magnification a is "7" (step 105).

Here, in each of steps 102 to 105, the CPU 51 sets a coefficient m-2 when the magnification magnification a is a-2, and sets a coefficient m-2 when the magnification magnification a-3. 3 and step 107), in the case of a-5, the coefficient ITI m is 5 and step 108), a-7
In this case, the coefficient is set to m-7 (step 109). When the coefficient m is defined in this way, the CPU 51 ends the preprocessing. In this case, for the original image data,
Enlargement processing corresponding to the defined value of the coefficient m will be performed.

Next, in step 105, if the enlargement magnification is not a-7, that is, if it does not correspond to each of the above enlargement magnifications a, the CPU 51
a − a / 2 (step 110), then n
= n
12), here, if n>64, return to the above step 102 and execute the steps from this step onwards, and conversely, if n>
64, define Free=1 (step 11
3) Finish the preprocessing.

For example, when the magnification is 12 times, this magnification is a-
12 does not correspond to each enlargement magnification a in steps 102 to 105 described above, so a-a/2-12/2-6
, n=nx2-1x2-2, am++5, n-2
is redefined as However, the redefined n(-2)
is smaller than 64, the steps from step 102 onward are repeated, and the enlargement factor a and coefficient n are redefined again.

That is, a - a / 2-6 / 2 = 3, n-n
X2-2X2-4, which is redefined as a-3 and n-4. Since this redefined n(-4) is smaller than 64, the above step 102 and subsequent steps are repeated, but in this case, the redefined 3w3 is
Since it corresponds to the expansion magnification a(-3) of 03, the coefficient m-3
The definition of is determined, and the definition of coefficient n-4 at this time is also determined. Therefore, coefficient m-3 and coefficient n-4 are obtained.

Note that if the magnification factor is a prime number other than the magnification factor 2.3.5.7 in the steps 102 to 1.5, for example, the magnification factor 11, then the steps 102 to 1
Since it does not correspond to each magnification of 05, the calculation of nmnX1 is performed until n>64 is satisfied, and when n>64 is satisfied, it is defined as Free-1 and the preprocessing ends.

In this case, for the original image data, the defined coefficient m
An enlargement process corresponding to the value of and an enlargement process corresponding to the value of the coefficient n are performed.

In this embodiment, the combination of the coefficient m and the coefficient n of the predetermined magnification factor (magnification coefficient) is as shown in FIG. In FIG. 7, the m column and the n column each show the coefficient value, and the other parts are the predetermined magnification values (
The value of the magnification coefficient to be set is shown. for example,
It can be seen that the magnification coefficient 12 is a combination of the coefficient m-3 and the coefficient n-114, and the magnification coefficient 40 is the combination of the coefficient m-5
, a combination of coefficients n-8.

Next, the enlargement processing operation performed based on the result of the above-mentioned preprocessing will be explained using the flowchart of FIG.

First, the CPU 51 checks whether Free is set to "1" (step 200), and if it is not set, the value of the coefficient m is "2", "3", or "5".
, "7", which value is defined (step 201); if it is 2, it will be enlarged by 2 times (step 202); if it is 3, it will be enlarged by 3 times (step 203). , 5, a 5x enlargement process (step 20
4) and 7, a 7x enlargement process (step 205) is performed, respectively.

For example, when the expansion magnification is 12 times (the magnification coefficient is 12), it is defined as a coefficient m-3 and a coefficient n-4, so the image data is first subjected to a 3 times expansion process. .

This three-fold enlarged image data is expanded into the work memory 59.

CP subjected to the enlargement process corresponding to the coefficient m in this way
U51 then judges whether the coefficient is n-1 (step 206), and if it is not the coefficient n-1, the step 2 is performed as described above.
Step 2
07), then divide the value of the coefficient n by 2, i.e. n −
The calculation of n/2 is performed (step 208), and then the process returns to step 206 and the steps from this step onward are executed. If n-1 is obtained in step 206 at that time, the enlargement process is terminated.

During the above-described enlargement process, the CPU 51 obtains offsets for each magnification as shown below.

That is, 2 times the offset - data (8 bits) x 23 times the offset - data (8 bits) x 35 times the offset - data (8 bits) x 57 times the offset - data (8 bits) x 7, and the CPU 51 , as shown in Figure 8,
The enlarged data stored at the address counted by the offset obtained as described above from the head of the corresponding bit pattern table of the enlarged table 56A is retrieved. Note that the table width of each bit pattern table is 16 bits for 2x, 24 bits for 3x, 40 bits for 5x, and 56 bits for 7x.

For example, when the size is 2 times, 16 bits of enlarged data are taken out, and when it is 3 times, 24 bits of enlarged data are taken out, and these read enlarged data are developed in the work memory 59.

That is, when the magnification is 12 times, the coefficient is m-3, so as shown in FIG.
The image data 81 that has been subjected to double enlargement processing is then subjected to double enlargement processing. By performing the 3x enlargement process in this way, n −
Since n/2 = 4/2-2, the image data 82 that has been enlarged twice is once again enlarged by 2.
Expansion processing is performed, which results in n = n / 2
-2/1-1, so the enlargement process for the image data ends.

Finally, the original image data 80 becomes image data 83 that has been subjected to 12 times enlargement processing.

In addition, in the case of Free-1 in step 200, the image data is subjected to Free enlargement processing and step 2 is performed.
09), then the enlargement process ends. This free enlargement process draws lines on the work memory 59 using a ruled line routine that arbitrarily enlarges 1 bit, similar to the conventional enlargement method. As shown in FIG. 10, this line is drawn using the number of bits counted from the left end of the source data (original image data) on the work memory 59 x the scale value (the value of the magnification coefficient)
Starting from position S.

In the above embodiments, the process of enlarging the image in the X direction has been described. Next, as shown in FIG. 11(a), the process of enlarging the image in the Y direction will be described. This Y-direction enlargement process can be performed by repeatedly copying the X-direction data by the magnification, as shown in FIG. 11(b). FIG. 11(a) shows a state in which the image has been enlarged twice in the Y direction.

In this example, is 1 in both the X direction and Y direction with respect to the image.
It is possible to enlarge by an integer multiple of ~128 times.

In the above embodiment, the enlargement process is performed in units of 8 bits, but the invention is not limited to this, and the enlargement process may be performed in units of multiple bits, for example, 16 bits at a time.

According to the above embodiment, when enlarging an image in the X direction, the enlarged data obtained by enlarging the image data in 8-bit increments is read out with reference to the enlarging table.
Since the enlargement process is performed, the enlargement process can be performed quickly.

〔Effect of the invention〕

As explained above, according to the present invention, an enlargement processing procedure corresponding to an enlargement coefficient corresponding to a factorization solution of a predetermined enlargement coefficient determined from a plurality of different enlargement coefficients set in advance is performed. , the image data is read out from the storage means and executed and enlarged, so even in the case of enlargement processing with a high magnification (high magnification coefficient), the enlargement that corresponds to the solution of the factorization of the magnification coefficient By executing the enlargement processing procedure corresponding to the magnification coefficient, there is an advantage that the enlargement processing can be performed at high speed.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an image printing device to which the image processing method according to the present invention is applied, FIG. 2 is a perspective view of a main part showing a recording section of the image printing device, and FIG. A block diagram showing an image supply device of a printing device, FIGS. 4 and 5 are flowcharts showing enlargement processing operations, FIG. 6 is an explanatory diagram for explaining the direction of enlargement processing for an image, and FIG. 7 shows a predetermined magnification. A combination list showing combinations of coefficients m and n for coefficients, FIG. 8 is an explanatory diagram for explaining extraction of enlarged data from the enlargement table, and FIG. 9 is for explaining the process of enlarging an image in the X direction. FIG. 10 is an explanatory diagram for explaining the free enlargement process in the X direction for an image. FIG. 11 is an explanatory diagram for explaining the process for enlarging the image in the Y direction. FIG. 3 is an explanatory diagram for explaining an enlargement processing operation. 11... Image supply device, 12... Recording section, 13...
・Power supply, 14... Panel, 51... CPU, 55.
...RAM. 56...ROM, 56A...enlargement table, 57.
...Program memory, 58...Character pattern memory, 59...Work memory, 60...Bitmap memory, 61...Bitmap controller. Fig. 2 Fig. Fig. Drawing input unit (source screen) 〆1-kunu71lr-lower image datater Fig. 10 (b) Fig. 11 Fig. 12

Claims (1)

[Scope of Claims] An image processing method that performs enlargement processing on image data according to a set magnification factor, comprising: a storage means for storing enlargement processing procedures corresponding to a plurality of different preset enlargement factor coefficients; a determining means for determining a solution to the factorization of the set magnification coefficient from among the respective magnification coefficients; and an enlargement processing procedure corresponding to the magnification coefficient corresponding to the solution to the factorization determined by the determination means. 1. An image processing method comprising processing means for reading data from a storage means and performing enlargement processing on image data.