JPH0585935B2 - - Google Patents

Description

Detailed Description of the Invention [0001] [Field of Industrial Application] The present invention relates to an image conversion device that uses an image memory to realize geometric transformation of an image, such as rotation, enlargement, reduction, etc. [0002] [0002] Special effects can be brought to an image by implementing geometric deformation of the image, such as rotation, enlargement, reduction, etc. recent years,
An image conversion device that uses an image memory has been proposed as an image conversion device that realizes this geometric transformation of an image. [0003] Methods for realizing geometric deformation of an image using an image memory include methods based on write address control and methods based on read address control. Write address control is based on information about which point in the output image each sample point of the input image corresponds to, and the address is controlled when writing to the image memory. It was done as it was done. On the other hand, read address control is based on information about which sample point in the input image each point of the output image corresponds to, and performs address control when reading from the image memory. It was designed to be carried out in a realistic manner. [Problems to be Solved by the Invention] Conventionally, in the write address control, only one sample point of the image memory corresponds to one sample point of the input image, so for example, the enlarged part is output. There was a problem with the image being intermittent. Therefore, conventionally, this write address control has not been used except for simple reduction without interruption. On the other hand, with read address control, even when the image is enlarged, the same sample point in the image memory can be read out repeatedly, so there will be no interruption in the output image. However, with this read address control, information on which sample point in the input image each point of the output image corresponds to must be calculated by, for example, finding the inverse function of a predetermined conversion function.
It was difficult to deal with arbitrary geometric deformations. Therefore, conventionally, the type of geometrical deformation of an image that can be realized using read address control has been greatly limited. [0005] After all, it is often more intuitive to provide information (calculated using a predetermined transformation function) about which point in the output image each sample point of the input image corresponds to, and as described above. If it is possible to avoid intermittent output images, it would be more convenient to use write address control. In view of these points, the present invention is designed to prevent intermittent output images from occurring in the output image using write address control, and also to easily perform complex image conversion processing in real time. [Means for Solving the Problems] The image conversion device of the present invention is an image conversion device that transforms an input image based on a conversion function set as shown in FIG. 1, and forms an output image. forming means 2 for forming a plurality of output small regions corresponding to each sample point on the input image based on the difference value at each sample point of the conversion function of each sample point;
The converting means 3 outputs the image information signal of each sample point on the input image as the image information signal of each sample point in the corresponding output small area. [Operation] According to the present invention, the difference value at each sample point of the conversion function is used to obtain a plurality of small output regions corresponding to each sample point, so the partial differential equation is calculated in advance. There is no need to calculate it in advance, the time required for calculation is relatively short, and complex image conversion processing can be easily performed in real time. [Embodiment] An embodiment of the image conversion device according to the present invention will be described below with reference to the drawings. In Figure 2A, each sample point of the input image is indicated by a black circle “●”.
, and on the X ₁ X ₂ rectangular coordinates, for example, its X ₁ and
X is placed at a position where the _two components are integer values. In addition, in FIG. 2B, each sample point of the output image memory is indicated by a white circle "〇", and on the Y ₁ Y ₂ orthogonal coordinates,
These are placed at positions corresponding to each sample point of the input image shown in FIG. 2A. Although only a few sample points of the input image and sample points of the output image memory are shown in FIGS. 2A and 2B, in reality, a large number of sample points exist. [0009] Here, from _{X 1}
The conversion formula to Y ₁ Y ₂ rectangular coordinates is [0010] [Equation 1] Y ₁ = ψ ¹ (X ₁ , X ₂ ) [0011] [Equation 2] Y ₂ = ψ ² (X ₁ , X ₂ ) [0012] and the sample point (x ₁ , x ₂ ) of the input image is located at the position (y ₁ , y ₂ ) (y ₁ = ψ ¹ ) on the Y ₁ Y ₂ rectangular coordinates as shown in FIG. 2B. (x ₁ , x ₂ ), y ₂ = ψ ² (x ₁ ,
x ₂ ). In this case, according to the conventional write address control method, the position near the position (y ₁ , y ₂ ) (y ₁ and y ₂ generally consist of an integer part and a decimal part, but for example, the value y with the decimal part truncated) Select only one sample point of the output image memory at the position specified by ' ₁ and _y'2 ), and assign one sample point of the input image ( _x1 ,
x ₂ ) image information. Therefore, when enlarging an image, for example, sample points where no image information is written are created in the output image memory between sample points where image information is written, resulting in gaps in the output image. In this example, the deviation at the sample point (x ₁ , x ₂ ) of the conversion equation is calculated on the Y ₁ Y ₂ orthogonal coordinates, corresponding to the unit area centered on the sample point (x ₁ , x ₂ ) of the output image. A predetermined area S ((y ₁ ,
y ₂ ) as the center, indicated by diagonal lines in _FIG .
x ₂ ), and the image information of the sample point (x ₁ , x ₂ ) of the input image is written into all sample points of the selected output image memory. On this Y ₁ Y _{2 orthogonal} coordinate _{, four} numerical _values a ₁₁ , a ₁₂ , a ₂₁ and a ₂₂ are used. and,
These four numbers a ₁₁ , a ₁₂ , a ₂₁ and a ₂₂ are the conversion formulas mentioned above, Y ₁ = ψ ¹ (X ₁ , X ₂ ), Y ₂ = ψ ² (X ₁ , X ₂ )
For each, sample points (x ₁ , x ₂ ) of the input image
It is determined using the partial differential value or difference value at . When using partial differential values, [0013] [Equation 3] a ₁₁ = ∂ψ ¹ (X ₁ , X ₂ )/∂X ₁ | (X ₁ , X ₂ ) = (x ₁ , x ₂ ) × 1/2 × α [0014] [Formula 4] a ₁₂ = ∂ψ ¹ (X ₁ , X ₂ )/∂X ₂ | (X ₁ , X ₂ ) = (x ₁ , x ₂ ) × 1/2 ×α [0015] [Math. 5] a ₂₁ = ∂ψ ² (X ₁ , X ₂ )/∂X ₁ | (X ₁ , X ₂ ) = (x ₁ , x ₂ )×1/2×α [0016 ] [Formula 6] a ₂₂ = ∂ψ ² (X ₁ , X ₂ )/∂X ₂ | (X ₁ , X ₂ ) = (x ₁ , x ₂ )×1/2×α [0017] , when using the difference value, [0018] [Formula 7] a ₁₁ = [ψ ¹ (x ₁ + 1, x ₂ ) − ψ ¹ (x ₁ , x ₂ )] × 1/2 × α [0019 ] [Formula 8] a ₁₂ = [ψ ¹ (x ₁ , x ₂ +1) − ψ ¹ (x ₁ , x ₂ )] ×1/2×α [0020] [Formula 9] a ₂₁ = [ψ ² ( x ₁ + 1, x ₂ ) − ψ ² (x ₁ , x ₂ )] × 1/2 × α [0021] [Math. 10] a ₂₂ = [ψ ² (x ₁ , x ₂ + 1) − ψ ² (x ₁ , x ₂ )]×1/2×α [0022] Here, α is a coefficient for area correction, and α>1. That is, Y ₁ Y ₂
When an interval occurs between the predetermined areas S defined on the orthogonal coordinates, this predetermined area is expanded to eliminate the interval between the predetermined areas S. In addition, the factors that cause the intermittence include the predetermined area S being a ₁₁ , a ₁₂ , a ₂₁ ,
There is an approximation using a ₂₂ , and calculation errors. [0023] At this time, on the Y ₁ Y ₂ orthogonal coordinates, a predetermined area as shown in FIG. 3B corresponds to a unit area centered on the sample point (x ₁ , x ₂ ) shown in the diagonal diagram in FIG. (Parallelogram area) S is determined. This parallelogram area S is located at the position (y ₁ , y ₂ ) corresponding to the sample point (x ₁ , x ₂ ) (y ₁ and y ₂ are integer parts i ₁
and i ₂ and fractional parts s ₁ and s ₂ . ) is defined by a vector whose Y ₁ component is a ₁₁ and whose Y ₂ component is a ₂₁ , and a vector whose Y ₁ component is a ₁₂ and whose Y ₂ component is a ₂₂ . [0024] In the end, the input image sample point (x ₁ ,
The sample points included within this parallelogram area S are selected as the sample points of the output image memory to be made to correspond to x ₂ ). Then, the image information at the sample point (x ₁ , x ₂ ) of the input image is written to the sample point of this selected output image memory,
Image conversion processing is performed at the sample point (x ₁ , x ₂ ) of the input image. By performing such processing over all sample points of the input image, image conversion processing is performed for the entire input image. [0025] FIG. 1 is a block diagram showing the entire image conversion device that performs such processing. In the figure, 1 indicates an input image memory, for example RAM
The sample points of the input image (x ₁ , x ₂ )
The image information of is written to the sample point (x ₁ , x ₂ ) of this input image memory 1. Also, this figure 1
, 2 is a processing device, 3 is an address generator,
4 is an output image memory. [0026] The processing device 2 has the conversion formulas Y ₁ = ψ ¹ (x ₁ , x ₂ ), Y ₂ = ψ ² (x ₁ ,
x ₂ ) information is input in advance, and image memories 1 and 4 are
Address control, arithmetic processing, etc. are performed for the data. Further, the processing device 2 sequentially specifies sample points of the input image to be subjected to image conversion processing. [0027] When the sample point (x ₁ , x ₂ ) of the input image is specified, the processing device 2 immediately uses the conversion formula to calculate the sample point (x _{1 , x 2 ) of the output image corresponding to this sample point (x 1} , x ₂ ). Position (y ₁ , y ₂ ) (y ₁ = ψ ¹ (x ₁ , x ₂ ), y ²
= ψ ² (x ₁ , x ₂ )) is calculated, and the above number 3,
Numerical values a ₁₁ , a 12 , a ₂₁ and a ₂₂ are calculated according to equations 4, 5 and 6, or 7, 8, ₉ and 10. In this case, the memory in which these operations are written according to the conversion formula, e.g.
A ROM is prepared in advance, and in this processing device 2, y ₁ , y ₂ , a ₁₁ , a ₁₂ , a ₂₁ and a ₂₂
It is also possible to read the value of . This processing device 2
The position (y ₁ , y ₂ ) and numerical value of the output image calculated by
Information on a ₁₁ , a ₁₂ , a ₂₁ and a ₂₂ is supplied to the address generator 3. [0028] The address generator 3 is configured as shown in FIG. 4, for example. In the figure, 30 indicates an arithmetic circuit, and its input terminals 30a, 30b, 30
Information on the numerical values a ₁₁ , a ₁₂ , a ₂₁ and a ₂₂ is supplied to c and 30d. In this arithmetic circuit 30, the numerical value
Based on the information of a ₁₁ , a ₁₂ , a ₂₁ and a ₂₂ , various numerical values w ₁ , w ₂ , l ₁ , l ₂ , p are used to actually determine the parallelogram area S as shown in FIG. 3B, for example. ₁ and p ₂ are calculated. Among the numerical values that determine the parallelogram area S calculated by this arithmetic circuit 30, w ₁ , l ₁
and p ₁ are supplied to the sample point calculation circuit 31A,
w ₂ , l ₂ and p ₂ are supplied to the sample point calculation circuit 31B. In addition, in this FIG. 4, 32 indicates an integer/decimal part separation circuit, and its terminals 32a and 32b have numerical values y ₁ (=i ₁ (integer part) + s ₁ (decimal part) and y ₂ ( = i ₂ (integer part) + s ₂ (decimal part)) The decimal parts s ₁ and s ₂ separated by this separation circuit 32 are supplied to the sample point calculation circuit 31A and , is supplied to the sample point calculation circuit 31B. In the sample point calculation circuit 31A, based on the information of the supplied numerical values w ₁ , l ₁ , p ₁ , s ₁ and s ₂ ,
As shown in FIG. 5, a parallelogram area S _A is defined on the Y ₁ Y ₂ orthogonal coordinates. In the same figure, white circle "〇"
is a sample point of the output image memory 4. The center of this area S _A is located at a position (s ₁ , s ₂ ) spaced apart by s 1 in the Y ₁ direction and s ₂ in _the Y ₂ direction from the reference sample point (0, 0). As a result, the sample point calculation circuit 31A calculates sample points included in this area _SA . Further, in the sample point calculation circuit 31B, the supplied numerical values w ₂ ,
With the information of l ₂ , p ₂ , s ₁ and s ₂ , as shown in Figure 5,
An area S _B is defined on the Y ₁ Y ₂ orthogonal coordinates. this territory
In the case of S _B , the center is also placed at (s ₁ , s ₂ ). As a result, this sample point calculation circuit 3
1B, sample points included in this area S _B are calculated. Information on the sample points calculated by these sample point calculation circuits 31A and 31B is supplied to a common sample point calculation circuit 33. This calculation circuit 33 calculates common sample points included in the areas S _A and S _B , that is, sample points that should be included in the parallelogram area S in FIG. 3B. In this case, as is clear from the explanation so far, the calculated sample point is the reference sample point (0,
0). [0031] Information on this common sample point is supplied to the address generation circuit 34. This address generation circuit 34 is supplied with information on integer parts i _{1 and i 2 of} y ₁ and y ₂ separated by the separation circuit 32 . This address generation circuit 34 can identify the reference sample point (0, 0) as (i ₁ , i ₂ ) by being supplied with the information of i 1 and i 2 , and at the same time, the common sample point mentioned above can be specified as (i ₁ , i ₂ ). , is specified on the output image memory 4. Based on this, the address generation circuit 34 generates an address signal ADo that specifies a common sample point on the output image memory 4, that is, a sample point that can be included in the parallelogram area S. , taken out to the output terminal 35. Address signal generated by address generator 3
AD ₀ is supplied via the processing device 2 to the output image memory 4 along with the control signal Sco. [0032] Further, the processing device 2 supplies the input image memory 1 with an address signal ADi and a control signal Sci that designate the sample point (x ₁ , x ₂ ).
Then, the image information _ID of the sample points (x ₁ , x ₂ ) of the input image written in the sample points (x ₁ , x _{2 )} is read out, and is stored in the output image memory 4 via the processing device 2 as described above. In this way, according to the image conversion device shown in FIG. 1, the sample point of the input image is specified by the processing device 2. , the above-mentioned processing is performed on each of them, and the image conversion processing is also performed on the entire input image.As described above, according to the image conversion device of this example, since it is based on write address control, arbitrary It is relatively easy to geometrically transform the sample points of the input image into a predetermined area (an area corresponding to the rate of change in the image) defined on the output image memory according to the sample points and the transformation formula. ), and compared to the conventional method where one sample point of the input image simply corresponds to one sample point of the output image memory, changes in the image are Even when a large proportion of the image is enlarged, for example, or when a transformation function other than linear transformation is given, sample points with no image information will not be created in the output image memory, resulting in gaps in the output image. There is no fear. Also, according to this example, the difference value at each sample point of the conversion function is used to find multiple output small regions corresponding to each sample point, so the partial differential is calculated in advance. There is no need to calculate a formula in advance, the time required for calculation is relatively short, and complex image conversion processing can be easily performed in real time.Next, while referring to FIG. Let us explain another embodiment of the image conversion device according to the invention. In this embodiment, each sample point (indicated by a black circle "●") of the input image is arranged as shown in FIG. 6A.
_A predetermined area _{S 0} is defined on _the X ₁ According to the area S ₀ , a predetermined area S is determined on the Y ₁ Y ₂ orthogonal coordinates where each sample point (indicated by a white circle "O") of the output image memory is arranged as shown in FIG. 6B. This predetermined area S is located at the position (y _{1 , x 2 ) corresponding to the sample point (x 1 ,} x ₂ ) of the input image.
_y2 ). Thereafter, each of the sample points of the output image memory included in the predetermined area S is selectively associated with the sample points of the input image included in the predetermined area _S0 . The conversion formula is [0034] [Math. 11] Y ₁ = ψ ¹ (X ₁ , X ₂ ) [0035] [Math. 12] Y ₂ = ψ ² (X ₁ , X ₂ ) [0036], and X ₁ When the predetermined area _S0 on the _X2 orthogonal coordinates is defined as an m×n rectangle as shown in FIG. 7A, the predetermined area S defined on _{the Y1Y2} orthogonal coordinates is as shown in FIG. 7B. position (y ₁ , y ₂ )
(parallelogram area defined by four numbers a _{11 ,} a ₁₂ , a ₂₁ and a ₂₂ centered on y 1 = ψ ₁ (x ₁ , x ₂ ), y ₂ = ψ ² (x 1 ^, x ₂ ) The four numerical values a ₁₁ , a ₁₂ , a ₂₁ and a ₂₂ are the sample points (x ₁ , x ₂ ) of the input image for each of the conversion formulas shown in equations 11 and 12 above.
It is determined using the partial differential value or difference value at . When using partial differential values, [0037] [Equation 13] a ₁₁ = ∂ψ ¹ (X ₁ , X ₂ )/∂X ₁ | (X ₁ , X ₂ ) = (x ₁ , x ₂ ) ×m/2×α [Math. 14] a ₁₂ = ∂ψ ¹ (X ₁ , X ₂ )/∂X ₂ | (X ₁ , X ₂ ) = (x ₁ , x ₂ )×n/2 ×α [0039] [Math. 15] a ₂₁ = ∂ψ ² (X ₁ , X ₂ )/∂X ₁ | (X ₁ , X ₂ ) = (x ₁ , x ₂ )×m/2×α [0040 _{] [} Math. 16] a ₂₂ = ψ ² (X ₁ , X ₂ ) _/ X ₂ | ₍ X 1 , When using the value, [0042] [Equation 17] a ₁₁ = [ψ ¹ (x ₁ + m, x ₂ ) − ψ ¹ (x ₁ , x ₂ )] × 1/2 × α [0043] Equation 18] a ₁₂ = [ψ ¹ (x ₁ , x ₂ + n) − ψ ¹ (x ₁ , x ₂ )] × 1/2 × α [0044] [Equation 19] a ₂₁ = [ψ ² (x ₁ +m, x ₂ ) − ψ ² (x ₁ , x ₂ )] × 1/2 × α [0045] [Formula 20] a ₂₂ = [ψ ² (x ₁ , x ₂ +n) − ψ ² (x ₁ , x ₂ )]×1/2×α [0046] Here, α is a coefficient for correcting the size of the parallelogram area, and α>1. In other words, if there is an interval between the parallelogram areas S defined on the Y ₁ Y ₂ orthogonal coordinates depending on the predetermined area S ₀ defined on the X ₁ X ₂ orthogonal coordinates, this parallelogram area S This is to eliminate gaps between the parallelogram areas S by enlarging the area. Note that the cause of the intermittence is that the predetermined area S
is approximated using a ₁₁ , a ₁₂ , a ₂₁ , and a ₂₂ , and there are calculation errors. In this way, a parallelogram area S is defined on the Y ₁ Y ₂ orthogonal coordinates corresponding to the predetermined area S ₀ defined on the X ₁ X ₂ orthogonal coordinates, and the input image contained within the predetermined area S _{0 is} As corresponding to the sample points of
Among the sample points in the output image memory, those included within the parallelogram area S are selected. However, each of the sample points of the output image memory included in this parallelogram area S has a predetermined area.
It is unknown which sample point of the input image included in S ₀ corresponds to. Therefore, next, sample points of the input image included in the predetermined area S ₀ corresponding to each of the sample points of the output image memory included in the parallelogram area S are determined. That is, it is determined which sample point in the output image memory each sample point of the input image included in the predetermined area S ₀ should correspond to. Now, the point (y ₁₀ , y ₂₀ ) in the parallelogram area S corresponding to the point (x ₁₀ , x ₂₀ ) in the predetermined area S ₀ is [0047] [Equation 21] ■■■ Tortoise shell [0002] ■■■ [0048] can be obtained by first-order approximation. In this equation, a' ₁₁ = 2/m a ₁₁ , a' ₁₂ = 2/n a ₁₂ a' ₂₁ = 2/m a ₂₁ , a' ₂₂ = 2/n a ₂₂ . In this example, from this, each of the sample points of the output image memory included in the parallelogram area S corresponds to which sample point among the sample points of the input image included in the predetermined area _S0 . The inverse function of the first-order approximation formula shown in Equation 21 above is used to determine. The inverse function of this first-order approximation formula is expressed as: [0049] [Equation 22] ■■■ Turtle Shell [0003] ■■■ [0050] With this number 22, ■■■ Turtle Shell [0004] ■■■ is the inverse matrix. Here, among the sample points of the output image memory included in the parallelogram area S , the sample point (y ₁₁ ,
y ₂₁ ), the point (x ₁₁ , x ₂₁ ), [0051] [ _Math . For example, a sample point (x' ₁₁ , x' ₂₁ ) within a predetermined area S ₀ close to the point (x ₁₁ , x ₂₁ ) is determined as a sample point of the input image to be associated with the point (x ₁₁ , y ₂₁ ). Note that for other sample points of the output image memory included in the parallelogram area S , sample points of the input image included in the corresponding predetermined area _S0 are determined in the same manner. In this way, the sample points of the output image memory that correspond to the sample points of the input image included within the predetermined area S ₀ defined on the input image are determined. In this case, the sample points of the output image memory that correspond to the sample points of the input image are the sample points of the output image memory that correspond to the sample points of the input image, that is, the sample points of the output image memory that correspond to the sample points of the input image, in other words, This is approximately the same as the sample point of the output image memory included in the predetermined area S defined on the output image memory. Eventually, the image information at the sample point of the corresponding input image is written to the sample point of this output image memory, and the predetermined area S ₀
The image conversion process at step ends. Note that the predetermined areas S ₀ as described above are sequentially taken on the input image, and image conversion processing is performed on the entire input image. [0053] FIG. 8 is a block diagram showing the entire image conversion device that performs such processing. This figure 8
In the figure, parts corresponding to those in FIG. 1 are denoted by the same reference numerals. The processing device 2 contains information on the conversion formulas Y ₁ = ψ ¹ (X _{1 ,} X ₂ ) and Y _{2 =} ψ ² ( _{X 1} , Information on numerical values m and n that determine the size of the predetermined area S ₀ defined above is input in advance, and address control and arithmetic processing for the image memories 1 and 4 are performed. Further, the processing device 2 sequentially specifies sample points of the input image that should be the center of a predetermined area S ₀ sequentially taken on the X ₁ X ₂ orthogonal coordinates. When a sample point (x _{1 ,} x ₂ ) of an input image is specified, this processing device 2 uses _a conversion formula to convert (Y ₁ Y ₂ orthogonal coordinates) position (y ₁ , y ₂ ) (y ₁ = ψ ¹
(x ₁ , x ₂ ), y ₂ =ψ ² (x ₁ , x ₂ )) are calculated, and the above-mentioned numbers 13, 14, 15, and 16 or 17, 18, 19, and According to 20
The numbers a ₁₁ , a ₁₂ , a ₂₁ and a ₂₂ are calculated. The information on the position (y ₁ , y ₂ ) on the output image and the numerical values a ₁₁ , a ₁₂ , a ₂₁ and a ₂₂ calculated by the processing device 2 is supplied to the address generator 3 . This address generator 3 is constructed as shown in FIG. In this address generator 3, based on the information of numerical values a ₁₁ , a ₁₂ , a ₂₁ and a ₂₂ ,
Various values w ₁ , w ₂ , l ₁ , l ₂ , p ₁ and p ₂ are calculated to determine the parallelogram area S as shown in FIG. Then, from these values, areas S _A and S _B are determined on the output image (on Y ₁ Y ₂ orthogonal coordinates) as shown in FIG. 10, and the common sample points included in these areas S _A and S _B are That is, sample points to be included in the parallelogram area S in FIG. 7B are calculated. After these sample points are identified as sample points (y ₁₁ , y ₂₁ ) on the output image memory 4, the address generator 3 specifies the sample points (y 11 , y ₂₁ ) on the output image memory 4. An address signal ADo specifying y ₂₁ ) is generated. and,
This address signal ADo is supplied to the output image memory 4 via the processing device 2 along with the control signal Sco , and is also supplied to the address generator 5. [0054] The address generator 5 is configured as shown in FIG. 9, for example. In the figure, 50 indicates an inverse matrix calculation circuit, and its terminals 50a, 50b, 50c
and 50d, the processing device 2 inputs the numerical values a ₁₁ , a ₁₂ ,
Information on a ₂₁ and a ₂₂ is provided. Then, in this arithmetic circuit 50, ■■■ Turtle Shell [0006] ■■■ is calculated. Information on the numerical values b ₁₁ , b ₁₂ , b ₂₁ and b ₂₂ is supplied to the address generation circuit 51 . The above-mentioned address signal ADo (having information on the sample points (y ₁₁ , y ₂₁ ) in the parallelogram area S ) is supplied to the terminal 51a of the address generation circuit 51, and the terminals 51b, 51c, 51d and Information on numerical values x ₁ , x ₂ , y ₁ and y ₂ is supplied from the processing device 2 to 51e. This address generation circuit 5
1, the sample point (x ₁₁ , x ₂₁ ) of the input image corresponding to the sample point (y ₁₁ , y ₂₁ ) in the parallelogram area S is calculated according to the above-mentioned equation 23, and is sent to the output terminal 51 f. is the input image sample point (x ₁₁ ,
An address signal ADi designating a sample point of the input image memory 1 in which image information corresponding to x ₂₁ ) is written is taken out. [0055] This address signal ADi obtained by the address generator 5 is passed through the processing device 2 to the control signal Sci.
It is also supplied to the input image memory 1. When the address signal ADi is supplied to the input image memory 1, the image information _ID of the sample point of the input image is read from the sample point of the input image memory 1, and the output image is outputted via the processing device 2. memory 4
is supplied and written to the sample point (y ₁₁ , y ₂₁ ) specified by address ADo . From this address ADo , calculate the sample point (x ₁ , x ₂₁ ) of the input image, read the image information of the sample point (x ₁₁ , x ₂₁ ) of the input image from input image memory 1, and store it in the output image memory. The process of writing to the sample points (y ₁₁ , y ₂₁ ) of No. 4 is repeated as many times as the number of sample points (y ₁₁ , y ₂₁ ) included in the parallelogram area S. In this way, sample points (x ₁ ,
An image conversion process is performed on a predetermined area S centered on x ₂ ). [0056] In this way, according to the image conversion device shown in FIG. 8, the processing device 2 sequentially determines the predetermined regions _S0 on the input image, and performs the above-described processing corresponding to each of the predetermined regions S0. Therefore, image conversion processing is performed over the entire input image. [0057] As described above, according to this embodiment, the same effects as those of the above embodiment are achieved, and it is not necessary to define a predetermined area on the output image for each sample point of the input image. This is convenient because the amount of processing can be reduced accordingly. According to the above embodiment, the image information obtained from the input image is once written to the input image memory, but the image information may be directly supplied from the input image to the output image memory. . [0058] According to the present invention, arbitrary geometric deformation is relatively easy because it is based on write address control. Moreover, the sample points of the input image can be converted into samples of the output image memory included in a predetermined area (area according to the conversion ratio of the image) determined on the output image memory according to the sample points and the conversion formula. Compared to the conventional method that simply corresponds one sample point of the input image to one sample point of the output image memory, it can be used even when the rate of change in the image is large, for example when enlarging the image. , even when a transformation function other than linear transformation is given, there will be no sample points with no image information in the output image memory, and there is no fear of intermittency in the input image. Furthermore, according to the present invention, a plurality of small output regions corresponding to each sample point are obtained using the difference value at each sample point of the conversion function.
There is no need to calculate the partial differential equation in advance,
The time required for calculation is relatively short, and complex image conversion processing can be easily performed in real time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an image conversion device of the present invention.

FIG. 2 is a diagram for explaining one embodiment of the present invention.

FIG. 3 is a diagram illustrating an embodiment of the present invention.

FIG. 4 is a block diagram showing a specific example of the configuration of an address generator.

FIG. 5 is a diagram for explaining one embodiment of the present invention.

FIG. 6 is a diagram for explaining another embodiment of the present invention.

FIG. 7 is a diagram for explaining another embodiment of the present invention.

FIG. 8 is a block diagram showing another embodiment of the present invention.

FIG. 9 is a block diagram showing a specific example of the configuration of an address generator.

FIG. 10 is a diagram illustrating another embodiment of the present invention.

[Explanation of symbols]

1 Image memory for input 2 Processing equipment 3,5 Address generator 4 Image memory for output

Claims (1)

[Claims] Claim 1. An image conversion device configured to convert an input image based on a set conversion function to form an output image, wherein a plurality of input small pixels each centered on each sample point are provided on the input image. a region forming means for defining a region and forming a plurality of output small regions corresponding to the plurality of input small regions based on a difference value at each sample point of a conversion function of each sample point; and a sample on the input image. An image conversion device comprising: conversion means for outputting an image information signal of a point as an image information signal of each sample point in a corresponding output small area.