JP2583515B2 - Image processing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an image processing technique for obtaining converted image data from original image data by complementation processing, such as enlargement, reduction, and rotation of an image. The present invention relates to a technique which is effective when applied to multi-value data such as color image data.

(Prior art)

Conventionally, for processing such as enlargement or reduction of binary image data (hereinafter also simply referred to as monochrome image data), the information processing journal Vol 26, No5 (published in September 1985)
Complementary processes such as the nearest neighbor method, the logical sum method, the nine-division method, and the distance inverse proportional method described on pages 920 to 925 are used. In the complementary processing for obtaining a converted image based on such an original image, the following processing is performed to obtain image data for a converted image to be drawn at predetermined destination coordinates in pixel units. It was done.

(1) A coordinate position of a transfer source corresponding to a predetermined coordinate position of a transfer destination is obtained to a decimal part based on an enlargement ratio or a reduction ratio. Here, the decimal part is a value indicating the ratio of the shift to the distance between a pair of pixels adjacent to each other when the transfer source coordinate position deviates from the pixel position.

(2) The image data around the transfer source coordinates obtained by the process (1) is acquired at a predetermined position predetermined by the mode of the complementing process.

(3) Using the image data of the transfer source obtained by the processing of (2) and the transfer source coordinates obtained by the processing of (1), a predetermined calculation predetermined in the complementary processing mode is performed. By doing so, image data to be sent to the transfer destination is generated. Here, the calculation may be a process of obtaining the brightness at the transfer source coordinates from predetermined surrounding original image data and generating image data according to the brightness.

[Problems to be solved by the invention]

However, the prior art is based on the assumption that monochrome image data is handled, and no consideration is given to handling multi-valued image data (hereinafter also simply referred to as color image data). There have been various problems in applying this method. That is, in the color image data, the operation when the predetermined operation is performed by the complementary processing method described in (3) becomes complicated according to the number of gradations of the color image data, and the amount of operation is large. It is difficult to realize with a relatively small system. Also,
When performing complementary processing in a relatively small-scale system, only the method that requires a relatively small amount of computation, such as the nearest neighbor method or the OR method, among various complementary processing methods may be used. Can not. Such a complementary method that requires a small amount of calculation has the advantage that high-speed calculation processing can be performed with a relatively small-scale system.
As described in the above-mentioned prior art document, there is a problem that the converted image is partially collapsed or missing from the original image, and the image quality is significantly deteriorated.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image processing apparatus capable of easily executing a supplementary process for obtaining high image quality on multi-tone image data such as color image data. Still another object of the present invention is to provide an image processing apparatus which can apply various complementary processing techniques for handling monochrome image data to a complementary processing for multi-tone image data such as color image data, using the method as it is. Is to provide.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[Means for solving the problem]

The outline of a representative invention among the inventions disclosed in the present application will be briefly described as follows.

That is, in an image processing apparatus that obtains converted image data from original image data by complementing processing, means for binarizing color image data as original image data in accordance with a predetermined rule, and a monochrome image based on the binarized data It includes means for performing a complementary processing operation substantially equivalent to processing on data, and means for generating color image data for forming a converted image based on the result of the complementary processing operation.

(Operation)

According to the above-described means, the monochrome image processing is performed by performing the complementary arithmetic processing for obtaining converted image data by enlarging, reducing, or rotating an original image composed of color image data based on the binarized data. Complementary processing for multi-tone image data such as color image data is achieved by using various complementary processing techniques for handling image data substantially as it is, thereby enabling original image data composed of color image data to be complemented. The present invention facilitates reduction of the calculation scale and high-speed calculation processing for obtaining a high-quality converted image without partial collapse or omission of the converted image.

〔Example〕

FIG. 1 is a functional block diagram showing a main part of an image processor which is an embodiment of an image processing apparatus according to the present invention.
FIG. 2 is a block diagram showing a hardware configuration for realizing each functional block shown in FIG. Although not particularly limited, the hardware configuration shown in FIG. 2 is generally configured by an arithmetic unit included in the image processor.

Although the image processor of the present embodiment is not particularly limited, a drawing control function via a frame buffer memory FBM as a bitmap memory coupled to a frame buffer address bus FBABUS as a local bus and a frame buffer data bus FBDBUS, and This is a peripheral controller that supports the display control function.

In the present embodiment, of the drawing control functions of the image processor, focusing on complementation processing in the case of obtaining a converted image by enlarging, reducing, or rotating an original image composed of color image data as multi-gradation data. explain.

In the present embodiment, although not particularly limited, original image data is held in a predetermined area of the frame buffer memory FBM, and converted image data generated based on the original image data is also temporarily stored in a predetermined area of the frame buffer memory FBM.

As shown in FIG. 3, the transfer source area including the original image data has a start point (x ₁ , y ₁ ) and an end point (x ₁ + XS, y) in a logical address space in units of pixels. ₁ + Y
S), width XS, height YS. Further, as shown in FIG. 4, the transfer destination area for storing the converted image data has a start point (x ₂ , y ₂ ) and an end point (x ₂ + XD) in a logical address space in units of pixels. , y ₂ + YD), width XD, and height YD. The data for these definitions is not particularly limited, but is included in a command given from a processor (not shown).

In the complementing process, the pixel address of the transfer destination area is
Designation is made so that scanning is sequentially performed in the x (+) direction and the y (+) direction from the sequential start point (x ₂ , y ₂ ) to the end point (x ₂ + XD, y ₂ + YD). The scanning direction and order are not limited to the present embodiment. Coordinate points (xd, yd) shown in Fig. 4
Is one scanning point corresponding to a predetermined pixel. The coordinate position of the transfer source area corresponding to this scanning point (xd, yd) is the third
In the figure, it is indicated by a point (xs, ys). This point (xs,
ys) is scanning point from the start of the transfer destination area _{(x 2, y 2) (} xd,
yd) and the ratio of the size of the transfer source area to the transfer destination area, and the like. Therefore, the coordinate point (xs, ys) of the transfer source area does not always correspond to the position of the pixel. In that case, the scanning point (xd, yd)
The data to be transferred to is obtained by the complementing process.

The complementing process employed in the present embodiment is not particularly limited, but is based on the inverse distance proportional method. That is, in principle, as shown in FIG. 5, a coordinate point (xs, s) as a source coordinate corresponding to a scan point (xd, yd) as a destination coordinate.
ys) is, when located between the pixels indicated by ○ mark, the coordinate point (xs, indirectly based on the image information corresponding to ys) into four image information of the position P ₀ to P ₃ around it Is to be given to In that case, the coordinate point (xs, ys)
Is not particularly limited, but how much image information corresponding to each of the points P _{0 to} P ₃ is based on the reciprocal of the distance from the point (xs, ys) to the four points P _{0 to} P ₃ It is determined depending on whether it affects the coordinate point (xs, ys). At this time, information corresponding to the points P ₀ to P ₃ are coordinate points (xs, ys)
Impact against the original almost regardless the enlargement ratio or the reduction ratio of the converted image to the image, the coordinate point for the rectangular area defined by four points P ₀ to P ₃ (xs, ys) solely related to the position of I do.

Therefore, in the present embodiment, although not particularly limited, four points P ₀
To a rectangular area which is by connexion defined in P ₃ in matrix 16
Divide the coordinate point (xs, ys) into one of the divided areas
And process them. Therefore, the coordinate point (xs, ys) what Yotsute to either included in the divided regions, distinguished by the manner of surrounding four points P ₀ to P ₃ information coordinate point (xs, ys) 16 ways to influence the can do. As shown in FIG. 5, the coordinate point (xs, ys) is included in an integer coordinate point ([xs],
[Ys]), a decimal distance Δx corresponding to a distance (xs− [xs]) with respect to a distance between pixels adjacent in the x direction, and a decimal number corresponding to a distance (ys− [ys]) with respect to a distance between pixels adjacent in the y direction. And the distance Δy. The integer coordinate point ([xs], [ys]) is also referred to as a transfer source integer part hereinafter. Further, the decimal distances Δx and Δy are also referred to as transfer source coordinate decimal parts hereinafter. In this description, for convenience, regions divided into 16 in a matrix are considered, but each divided region can be considered to be equivalent to 16 lattice points.

Coordinate points in a rectangular area this is defined by four surrounding points P ₀ to P ₃ as (xs, ys) when the position of the is specified in one position from among 16 types, around four points P ₀ to information the coordinate point P ₃ (xs, ys) impact on will be different depending on information corresponding to the four surrounding points P ₀ to P _3. In this embodiment, an original image composed of color image data and a converted image are handled.
Information corresponding to the four surrounding points P ₀ to P _3, shall be given by the binary data of the original image. Therefore, the surrounding four points
P ₀ to the combination information corresponding to P ₃ is a sixteen.

In the present embodiment, although not particularly limited, four surrounding points P _{0 to} P ₀
Complementary table TABLE 16 types according to the combination of each of the binary information corresponding to P ₃ having been turned into a ROM (read only memory).

An example of the 16 complementary table TABLEs is shown in FIG. Figure 6 is an illustration conceptually as adaptable configuration complementary table around four points P ₀ to P _3. In FIG. 6, each of 16 complementary tables indicated by numbers 0 to 15
In TABLE, among surrounding four points P ₀ to P _3, ○ mark corresponds to a pixel of the source data is binarized becomes "0" as the color image data included in the transfer source area, facilities hatching The circles correspond to pixels that have been binarized from source data such as color image data included in the transfer source area and have become “1”. Then, in each complementary table, the surrounding 4
In each of the 16 divided matrix areas surrounded by points P _{0 to} P ₃ , the area including the number 0 means that the image information corresponding to the point P ₀ is affected, and the area including the number 1 is means being affected by the image information corresponding to the point P _1, a region containing a number 2 means that the affected image information corresponding to the point P _2, the area including the numbers 3 points
Which means that the influence of the image information corresponding to P _3.

In practice, the meaning of each such divided area is 2
Although defined by bit data and not particularly limited, the numeral 0 in each divided area is “0,0”, the numeral 1 is “0,1”, the numeral 2 is “1,0”, and the numeral 3 is “0,1”. 1,1 ". Accordingly, each complementary table conceptually having such a meaning is not particularly limited, but is composed of 32-bit data as shown in FIG. The sequence of each bit is not particularly limited, in response to the direction of the address scanning for the destination area, for example, as indicated by arrows in FIG. 7, in the order, from the point P ₀ to point P _3, i.e. from the divided region E ₀ are in accordance with the order of E _15. In this case, whether to correspond to either the divided regions E ₁₅ to correspond to upper 32 bits of data in the divided area E ₀ it can be determined appropriately.

Next, a configuration for obtaining converted image data from original image data composed of color image data using the complement table TABLE will be described mainly with reference to FIG.

In FIG. 1, DSCAN is a transfer destination coordinate generation unit that generates scanning coordinates (hereinafter also simply referred to as transfer destination coordinates) (xd, yd) in the transfer destination area as shown in FIG. The destination coordinates (x) generated by the destination coordinate generator DSCAN
d, yd) is stored in the transfer destination coordinate register CPD.

SSCAN is a source coordinate generation unit that generates source coordinates (xs, ys) corresponding to destination coordinates (xd, yd). As shown in FIG. 5, the source coordinate generation unit SSCAN converts the source coordinate (xs, ys) from the source coordinate integer part ([xs],
[Ys]) and the transfer source coordinate decimal part (Δx, Δy).
It should be noted that, although not particularly limited, the decimal part (Δx, Δ
y) can be converted into integer data for convenience. The transfer source coordinate integer part ([xs], [ys]) is stored in the transfer source coordinate integer part register CPS, and the transfer source coordinate decimal part (Δ
x, Δy) are stored in the transfer source coordinate decimal part register CPSF.

The source coordinate generation unit SSCAN stores the source coordinate integer part ([xs], [y
s]), the addresses of the pixels in the source area corresponding to the four points P _{0 to} P ₃ (see FIG. 5) around the source coordinates (xs, ys) are calculated and given to the data read unit FBRD. . The data read unit FBRD stores the transfer source color image data corresponding to the given address, that is, the area around the transfer source coordinates (xs, ys).
It reads the source color image data corresponding to the point P ₀ to P _3, and stores the source color image data register IMGREG.

MAPALU is the source color image data register IMGR
The source color image data corresponding to the four points P ₀ to P ₃ stored in the EG is binarization unit for binarizing. This binarization unit MA
PALU performs a binarization process based on comparing the source color image data each corresponding to four points P ₀ to P ₃ and the reference data of the reference color register MAPCL, binary data MP
_0, to generate the _{MP 1, MP 2, MP 3} . In this case, the operation mode for binarization is specified by the binarization mode setting register MAP.

Here, the binarization mode is not particularly limited, but can be set to any one of eight patterns by 3-bit control data. Operation modes of the eight is the source color image transfer to the original color image data [Pi] corresponding to the data register IMGREG stored in the said four-point P ₀ to P _3, the reference is set to a reference color register MAPCL color The magnitude relationship with the data [MAPCL] is as follows.

Condition for setting binary data to “1” [MAPCL] = [Pi] [MAPCL] ≦ [Pi] [MAPCL] <[Pi] Always “1” regardless of the magnitude relationship [MAPCL] ≠ [Pi] [MAPCL] ≧ [Pi] [MAPCL]> [Pi] Always “0” irrespective of the magnitude relation MAPREG converts the data MP ₀ , MP ₁ , MP ₂ , MP ₃ binarized by the binarization unit MAPALU. This is a binary data register to be stored. The 4-bit binarized data MP ₀ , MP ₁ , MP ₂ , MP ₃ stored in the binarized data register MAPREG selects one from the 16 types of complementary tables shown in FIG. And an address signal to be supplied to the complement table TABLE. For example, when MP ₀ = 0, MP ₁ = 1, MP ₂ = 0, and MP ₃ = 0, the No. 2 complementary table in FIG. 6 is selected.

The transfer source color image register IMGREG, reference color register MAPCL, binarization mode setting register MAP, binarization unit
The MAPALU and the binarized data register MAPREG constitute a gradation reduction processing unit MAPUNIT as an example of gradation reduction processing means for reducing the gradation of multi-gradation data forming the original image.

The data of one complementary table selected as described above, that is, 32-bit data as shown in FIG. 8, is supplied to the barrel shifter SHIFT. Barrel shifter SHF
IT is based on the shift amount determined by the source coordinate decimal part (Δx, Δy) stored in the source coordinate decimal part register CPSF as shown in FIG. 7 and FIG. The 2-bit data included in the divided area to which the transfer source coordinates (xs, ys) belong is cut out. For example, as shown in FIG. 7, the transfer source coordinates (xs, ys) correspond to the divided area E ₅
, The complement table forming the bit string as shown in FIG. 8 is shifted 10 bits to the left, and “0, 0” of the eleventh and twelfth bits in the original array are directly read. . Alternatively, control data corresponding thereto is output.

The complement table TABLE and the barrel shifter SHIFT
Constitutes a complementary processing unit IUNIT as an example of a complementary processing unit that performs a complementary process based on data whose gradation has been reduced by the gradation reduction processing unit.

The 2-bit data cut out by the barrel shifter SHIFT or the corresponding control data is supplied to the transfer destination color generation unit COLGEN. The 2-bit cutout data or control data corresponding thereto supplied to the transfer destination color generation unit COLGEN is control data for specifying a color to be written to the transfer destination or calculating a color. For example, when the 2-bit cutout data is used as a selection signal for selecting the corresponding transfer source color image data from the transfer source color image data register IMGREG, the cutout data may be included in the transfer destination color generation unit COLGEN. One transfer source color image data corresponding to the 2-bit cutout data is selected by a multiplexer (not shown). For example the if the 2-bit cut data as described is "0,0" is the source color image data of the pixel of point P ₀ corresponding thereto is selected.

The output of the barrel shifter SHIFT can also be used for starting a predetermined microprogram in a microprogram control means (not shown). That is, it can be used to start a microprogram for selecting predetermined data stored in the transfer source color image data register IMGREG. In that case, barrel shifter SHIF
The output of T need not be directly supplied to the destination color generation unit COLGEN. Further, the transfer destination color generation section COLGEN performs not only the selection processing of the predetermined color image data in the transfer source color image data register IMGREG, but also the reference color register MAPC for the selected predetermined transfer source color image data.
It is also possible to perform other operations such as a color operation with the L reference color data and modify it.

In this way, the destination color generation unit COLGEN generates color image data having the same gradation as the source color image data according to the result of the complementing process based on the binarized data.

The transfer destination color generation unit COLGEN, transfer source color image data register IMGREG, and the like are provided with a multi-gradation for generating converted image data having the same gradation as the original image data based on the information obtained by the complement processing means. The multi-gradation generation unit COLUNIT is configured as an example of the generation unit.

The color image data generated by the destination color generation unit COLGEN is supplied to a data write unit FBWT. The data write unit FBWT transfers the color image data supplied thereto to the transfer destination area on the frame buffer memory FBM in accordance with the address given by the transfer destination coordinates (xd, yd) stored in the transfer destination coordinate register CPD. Write.

Next, the correspondence between each functional block shown in FIG. 1 and FIG. 2 will be described.

The destination coordinate generator DSCAN, the source coordinate generator SSCA
N and the multi-tone generation unit COLUNIT are configured by an arithmetic unit ALU and a temporary register group TDR. The data write unit FBWT and the data read unit FBRD are configured by a memory address register MAR, a read data buffer register RDBR, a write data buffer register WDBR, a barrel shifter SHIFTER, and a temporary register group TDR. The destination coordinate register CPD, source coordinate integer part register CPS, source coordinate decimal part register CPSF, source color image data register IMGREG, binary mode setting register MAP, and 2
Valued data register MAPREG is a temporary register group TDR
Included in. The binarizing unit MAPALU of FIG. 1 corresponds to the comparator COMP of FIG. 2, and the barrel shifter SHIF of FIG.
T corresponds to the barrel shifter SHIFTER in FIG. Further, in FIG. 2, the supply of the address signal to the complementary table TABLE is performed via the address register TAR, and the reading of the data from the complementary table TABLE is performed via the data buffer TDBUF. Figure 2 shows the temporary latch TLA
T, a shift amount control register SFTN is provided. The shift amount control register SFTN stores control data formed based on the transfer source coordinate decimal part.

In FIG. 2, the arithmetic unit ALU includes a destination coordinate generating unit DSCAN, a source coordinate generating unit SSCAN, and a multi-gradation generating unit.
COLUNIT is configured to share each, but may be separately provided. Further, the hardware configuration shown in FIG. 2 is not particularly limited, but its operation is controlled by a microprogram.

Next, an example of the complementary processing operation in the present embodiment will be described based on the flowcharts shown in FIGS. 9 (A) and 9 (B).

In obtaining the converted image data by enlarging or reducing the original image data, the transfer of the transfer destination area (xd, y
First, a scan start point (x ₂ , y ₂ ) is set at the transfer destination coordinates (xd, yd) (steps S1 and S2). Next, corresponding transfer source coordinates (xs, ys) are generated (steps S3, S4). It is determined whether or not the source coordinates (xs, ys) generated in this way include a decimal part, that is, whether or not the source coordinates (xs, ys) do not match the pixels of the source area. This is performed (step S5). For example, step
The transfer source coordinates (xs, ys) immediately after S1 and S2 often coincide with the start point (x ₁ , y ₁ ) in the transfer source area. In such a case, when the source coordinates (xs, ys) coincide with the pixels of the source area, the binarization processing and the complementing processing are substantially non-operation, and the source coordinates (xs, ys) are set. ys) is read out from the source area and transferred to the destination coordinates (xd, y) via the destination color generation unit COLGEN.
A process for writing to the transfer destination area corresponding to d) is executed (step S6).

On the other hand, if the transfer source coordinates (xs, ys) do not match the pixels in the transfer source area, the transfer is performed based on the transfer source integer part ([xs], [ys]) generated in steps S3 and S4. original coordinates (xs, ys) reads the color image data corresponding to the four surrounding points P ₀ to P ₃ from the source region of the source color image data register IMGREG (step S7). Color image data read out is converted into a binary unit MAPALU to Yotsute binary data MP ₀ to MP ₃ (step S8). The binarized data MP ₀ to MP ₃ is the address data for accessing the complementary table TABLE (step S9), 16
One complementary table is selected from the types (step S10). Note that the formula shown in step S9 is different from the format of the actual address data, and is a formula for obtaining a number corresponding to the number of the complementary table shown in FIG.

When one supplementary table is selected, steps S3 and
Based on the source coordinate decimal parts Δx, Δy generated in S4,
The corresponding bit on the complement table is the barrel shifter SHIFT
The operation for multi-gradation equivalent to the original image is specified to the transfer destination color generation unit COLGEN (step S1).
1). Accordingly, the destination color generation unit COLGEN generates color image data having the same gradation as the source color image data according to the result of the complementing process based on the binarized data (step S12).

The color image data generated by the transfer destination color generation unit COLGEN is written to the transfer destination area on the frame buffer memory FBM according to the address given by the transfer destination coordinates (xd, yd) (step S13).

When the color image data is written to one predetermined transfer destination coordinate (xd, yd) by step S6 or S13, if the data transfer element remains next, in other words,
Destination coordinates (xd, yd) scanning end point of _{(x 2 + XD, y 2} + YD)
Is determined, and the next operation is determined. That, xd whether the determination is carried out to match the x ₂ + XD (step S14), and if they do not match, proceed one main scanning in the lateral direction by adding 1 to the previous value xd ( Step S1
5) Return to step S3. If the determination results in step S14 match, it is determined whether yd matches y ₂ + YD (step S16). If the discrimination result in step S16 does not match, 1 is added to the previous value yd, and the vertical sub-scan is advanced by one (step S17), and step S2 is performed.
Return to If the determination result in step S17 is a match, the scanning of the transfer destination coordinates (xd, yd) ends at (x ₂ + XD, y ₂ +
YD) has been reached, and a series of drawing operations ends.

According to the above embodiment, the following operation and effect can be obtained.

(1) By providing means for binarizing multi-valued color image data, the original image data constituted by the color image data is temporarily converted to binary monochrome image data and complemented. As a result, it is possible to apply the supplementary processing for monochrome image data, which is simple and requires a small amount of computation, to original image data composed of color image data.

(2) By providing means for restoring multi-gradation data such as color image data using the result of the complementing process for the monochrome image data, it is possible to perform the complementing process with the monochrome image data and It is possible to enlarge or reduce the original image data without reducing the number.

(3) Multi-gradation data which is simple in processing and requires a small amount of computation by having a binarizing means and means for restoring or generating multi-gradation data such as color image data by the above-mentioned respective effects Complementary processing can be realized.

(4) In particular, high-speed arithmetic processing can be achieved by having a complementary table necessary for the complementary processing in advance.

(5) The contents of the complement table are converted image data based on the inter-pixel position in the original image data storage area obtained corresponding to the predetermined pixel storing the converted image data and a predetermined number of pixel positions around the pixel. When the multi-grayscale data is a set of data that can be relatively determined, the generation of the multi-grayscale data based on the binarization result can be performed extremely efficiently.

Although the invention made by the present inventors has been specifically described based on the embodiments, it is needless to say that the present invention is not limited to the above embodiments and can be variously modified without departing from the gist thereof. No.

For example, the data pattern of the complement table described in the embodiment can be variously changed according to the type of the complement process. In addition, RAM has been added to facilitate those changes.
(Random access memory) and can be stored in rewritable storage means.

In the above embodiment, the number of divisions of each complementary table is 16 because the decimal part is 1/4 unit of the pixel-to-pixel distance. However, this can be changed according to the unit of the decimal part. Further, in the above-described embodiment, the number of the types of the complementing tables is set to 16, but this is because the complementing process is performed by focusing on four points around the transfer destination coordinates that do not match the pixels. The type of the complement table also increases or decreases. Therefore, the number of surrounding attention or reference points in the complementing process is not limited to the four points in the above embodiment, but can be changed as appropriate.

Further, the complementing process is not limited to the format using the complementing table. However, in that case, the processing speed is reduced.

In the above-described embodiment, the means for reducing the gradation
Although the binarization has been described as an example, quaternization, octalization, and the like can be adopted as long as the gradation of the original image data is reduced.

In the above embodiment, enlargement and reduction are described as examples. However, the complementary processing technique applied to the enlargement and reduction can be similarly applied to the figure rotation algorithm.

In the above description, the case where the invention made by the present inventor is mainly applied to a processor dedicated to image processing, which is the field of use, has been described. However, the present invention is not limited to this, and it is possible to enlarge, reduce, rotate The present invention can be widely applied to various data processing apparatuses having a drawing processing function such as the above. The present invention can be applied to at least a condition for obtaining converted image data from original image data via a complementing process.

〔The invention's effect〕

The effects obtained by the representative inventions among the inventions disclosed in the present application will be briefly described as follows.

That is, by providing a means for binarizing multi-valued color image data, the complementing process for monochrome image data, which is simple and requires a small amount of computation, is performed for the original image data composed of color image data. It can be applied, and has means for restoring multi-tone data such as color image data using the result of the complementing process on the monochrome image data. Enlargement and reduction of the original image can be performed without reducing the number of tones of the image.
The monochrome complementing process requires a smaller amount of calculation and is simpler than the direct complementing process for color image data, so that the amount of hardware required for the system configuration can be reduced.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing a main part of an image processor which is an embodiment of an image processing apparatus according to the present invention. FIG. 2 is a hardware configuration for realizing each functional block shown in FIG. FIG. 3 is an explanatory diagram for defining a source area, etc. FIG. 4 is an explanatory diagram for defining a destination area, etc. FIG. FIG. 6 is an explanatory diagram showing the correspondence relationship with the preceding coordinates, FIG. 6 is an explanatory diagram showing a conceptual example format of a supplementary table, and FIG. 7 is a detailed conceptual format of one supplementary table included in FIG. FIG. 8 is an explanatory view showing a data pattern of a practical complement table corresponding to FIG. 7, and FIGS. 9 (A) and 9 (B) are flowcharts for explaining an enlargement / reduction operation. MAPUNIT: gradation reduction processing unit, IUNIT: complement processing unit, CO
LUNIT: Multi-tone generator, DSCAN: Transfer destination coordinate generator,
CPD: destination coordinate register, SSCAN: source coordinate generator, CPS: source coordinate integer register, CPSF: source coordinate decimal part register, FBM: frame buffer memory, IMGREG: source color Image register, MAPALU ……
Binarization section, MAPCL ... reference color register, MAP ... binary mode setting register, MAPREG ... binary data register
TABLE …… Complementary table, SHIFT …… Barrel shifter, COLG
EN: destination color generation unit, xd, yd: destination coordinates, xs, ys
… Transfer source coordinates, [xs], “ys”… Transfer source coordinate integer part,
Δx, Δy... Decimal part of transfer source coordinates.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Akihiro Katsura 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd.Hitachi Research Laboratory (72) Inventor Shigeru Matsuo 4026 Kuji-machi, Hitachi City, Ibaraki Prefecture Hitachi Research, Ltd. In-house (72) Inventor Masakatsu Yokoyama 3-2-1 Sachimachi, Hitachi City, Ibaraki Prefecture Inside Hitachi Engineering Co., Ltd.

Claims (4)

(57) [Claims] 1. An image processing apparatus for obtaining converted image data from original image data through a complementing process, comprising: a tone reduction processing means for reducing the tone of multi-tone data constituting the original image data; Complementary processing means for performing complementation processing based on data whose gradation has been reduced by the reduction processing means, and conversion image data having the same gradation as the original image data based on information obtained by the complementary processing means. An image processing apparatus comprising: 2. A method according to claim 1, wherein said gradation reduction processing means compares the multi-gradation original image data with reference gradation data and binarizes the original image data based on a result of the comparison. The image processing device according to claim 1. 3. The image processing apparatus according to claim 1, wherein said complement processing means includes a plurality of complement tables in which the contents of the complement processing are patterned. 4. The conversion table according to claim 1, wherein said complementary table is based on a pixel-to-pixel position and a predetermined number of pixel positions around the pixel in an original image data storage area obtained corresponding to a predetermined pixel storing the converted image data. 4. The image processing apparatus according to claim 3, wherein the data for relatively determining the multi-gradation data is included in a pattern.