JP2010199663A - Image processing apparatus and image processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enlarge and rotate original image information without a storage area for storing image information after enlargement. <P>SOLUTION: The image processing apparatus includes an inverse matrix generation means 21 for generating an inverse matrix of a matrix for coordinate conversion including components of enlargement and rotation when image information on xy coordinates is enlarged and rotated to be developed on xy coordinates of a storage means, a circumscribed rectangle acquisition means 22 for obtaining coordinates corresponding to a circumscribed rectangle on the xy coordinates of the storage means 4 with respect to image information after conversion when the original image information is enlarged and rotated, a coordinate extraction means 23 for extracting coordinates in an area of the image information after conversion inside the circumscribed rectangle obtained by the circumscribed rectangle acquisition means 22, and a duplication means 3 for obtaining coordinates corresponding to the original image information using the inverse matrix generated by the inverse matrix generation means 21 with respect to the coordinates extracted by the coordinate extraction means 23, acquiring pixel values of the obtained coordinates, and duplicating the acquired pixel values to the extracted coordinates of the storage means 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image processing apparatus and an image processing program.

  Conventionally, when performing processing to rotate image information (image data) at an arbitrary angle, the original image information is temporarily enlarged and then rotated to an arbitrary angle. This is because the resolution of the original image information is different from the resolution of the image information after the rotation process, and therefore the enlargement process of the original image information is performed to match the resolution before the rotation process is performed.

  Here, Patent Document 1 discloses a technique for drawing a plurality of lines in a straight line when rotating image information at an arbitrary angle.

JP-A-6-274610

  An object of the present invention is to provide a technique for processing without enlarging and rotating original image information without using a storage area for storing the enlarged image information.

  In the invention according to claim 1 of the present application, when the original image information on the xy coordinates is enlarged and rotated to be developed on the xy coordinates of the storage means, an inverse matrix that generates an inverse matrix of a matrix of coordinate transformation including the components of the enlargement and rotation. A matrix generation unit, a circumscribed rectangle obtaining unit for obtaining coordinates corresponding to a circumscribed rectangle on the xy coordinates of the storage unit in the converted image information when the original image information is enlarged and rotated, and the circumscribed rectangle obtaining unit A coordinate extraction means for extracting coordinates that fall within the area of the converted image information inside the circumscribed rectangle obtained, and an inverse matrix generated by the inverse matrix generation means for the coordinates extracted by the coordinate extraction means Copying means for obtaining coordinates corresponding to the original image information, obtaining a pixel value of the obtained coordinates, and copying the obtained pixel value to the extracted coordinates of the storage means; An image processing apparatus to obtain.

  The invention according to claim 2 of the present application is the image processing apparatus according to claim 1, wherein the inverse matrix generation unit generates an inverse matrix of the coordinate conversion matrix including the translation component of the original image information.

  In the invention according to claim 3 of the present application, as the translation component, the minimum or maximum value of each of the x-coordinate and y-coordinate of the original image information and the minimum of each of the x-coordinate and y-coordinate of the converted image information The image processing apparatus according to claim 2, wherein an x-direction component and a y-direction component necessary for making the value or the maximum value coincide with each other.

  In the invention according to claim 4 of the present application, when executing the image processing for expanding and rotating the original image information on the xy coordinates and expanding the original image information on the xy coordinates of the storage means, the inverse of the matrix of the coordinate conversion including the components of the expansion and rotation is performed. An inverse matrix generating step for generating a matrix, a circumscribed rectangle obtaining step for obtaining coordinates corresponding to a circumscribed rectangle on the xy coordinates of the storage means in the converted image information when the original image information is enlarged and rotated, and A coordinate extraction step for extracting coordinates within the area of the converted image information inside the circumscribed rectangle obtained in the circumscribed rectangle acquisition step, and the coordinates extracted by the coordinate extraction step are generated in the inverse matrix generation step. A coordinate corresponding to the original image information is obtained using the inverse matrix, a pixel value of the obtained coordinate is obtained, and the obtained pixel value is stored in the storage means. An image processing program for executing a duplication step of duplicating to the extracted coordinates into the computer.

  In the invention according to claim 1 of the present application, when the original image information is enlarged and rotated, the pixel value can be directly developed to the corresponding coordinates of the storage means without going through the area for storing the information after the enlargement.

  In the invention according to claim 2 of the present application, in addition to the enlargement and rotation of the original image information, the pixel value is directly expanded to the corresponding coordinates of the storage means without going through the area for storing the information after the enlargement for the process including the parallel movement. Is possible.

  In the invention according to claim 3 of the present application, it is possible to perform enlargement and rotation processing in which the positions of the minimum value or the maximum value of the x-coordinate and y-coordinate of the original image information are matched.

  In the invention according to claim 4 of the present application, when enlarging and rotating the original image information, it is possible to directly expand the pixel value to the corresponding coordinates of the storage means without going through the area for storing the enlarged information.

It is a block diagram explaining the schematic structure of the image processing apparatus which concerns on this embodiment. It is a schematic diagram explaining the concept of the conventional expansion and rotation process. It is a schematic diagram explaining the concept of the process in the image processing apparatus which concerns on this embodiment. It is a flowchart explaining the image processing program which concerns on this embodiment. It is a schematic diagram explaining normal rotation and rotation with a parallel movement. It is a schematic diagram explaining calculation of a parallel displacement component. It is a schematic diagram which shows a parallel displacement component. It is a schematic diagram explaining a circumscribed rectangle and an edge list. It is a schematic diagram explaining the inverse transformation of the coordinate by an inverse matrix, and replication of a pixel value.

Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described. The description will be given in the following order.
1. 1. Configuration of image processing apparatus 2. Comparison with conventional processing 3. Image processing program Concrete example

<1. Configuration of Image Processing Device>
[Schematic configuration]
FIG. 1 is a block diagram illustrating a schematic configuration of an image processing apparatus according to the present embodiment. FIG. 1A is an overall configuration, and FIG. 1B is a detailed configuration of a rotating unit. As shown in FIG. 1 (a), the image processing apparatus according to the present embodiment expands and rotates original image information and expands it in the storage means 4. The input means 1, the rotation means 2, and the duplication means 3 are provided. I have.

  The input means 1 is a part for inputting original image information. The original image information is composed of, for example, a page description language, and is expanded into bitmap data on logical xy coordinates by the input unit 1. The rotation means 2 is a part that performs rotation processing including enlargement of original image information. The rotating means 2 will be described in detail later.

  The duplicating unit 3 performs a process of duplicating the pixel values of the coordinates of the corresponding original image information from the coordinates of the rotated image processed by the rotating unit 2. The storage unit 4 is a storage area in which the pixel values copied by the copying unit 3 are expanded as converted image information, and a page buffer is used, for example.

[Configuration of rotating means]
As shown in FIG. 1B, the rotation unit 2 includes an inverse matrix generation unit 21, a circumscribed rectangle acquisition unit 22, and a coordinate extraction unit 23. The inverse matrix generation unit 21 is a part that generates an inverse matrix of a matrix of coordinate transformation including an expansion and rotation component when expanding and rotating the original image information on the xy coordinates and expanding the original image information on the xy coordinates of the storage unit 4. .

  The circumscribed rectangle obtaining unit 22 is a part for obtaining coordinates corresponding to the circumscribed rectangle on the xy coordinates of the storage unit 4 in the converted image information when the original image information is enlarged and rotated. The coordinate extracting unit 23 is a part for extracting coordinates that are within the area of the converted image information inside the circumscribed rectangle obtained by the circumscribed rectangle obtaining unit 22.

<2. Comparison with conventional processing>
Here, the processing concept of the image processing apparatus according to the present embodiment will be described in comparison with the conventional processing concept.

[Conventional processing]
FIG. 2 is a schematic diagram for explaining the concept of conventional enlargement and rotation processing. In the conventional process, the enlargement matrix M1 is used for the enlargement process of the original image information, and the rotation matrix M2 is used for the arbitrary angle rotation process. That is, first, the original image information is enlarged by the enlargement matrix M1. Thereafter, the enlarged image is subjected to rotation processing at an arbitrary angle using the rotation matrix M2.

  When the resolution of the converted image information differs from the original image information, it is necessary to enlarge the original image information once. That is, if the original image information is directly enlarged and rotated using a matrix obtained by combining the enlargement matrix M1 and the rotation matrix M2, the pixel information of the converted image information will be missing. For this reason, it is necessary to enlarge the original image information once and generate values for all the enlarged pixels, and then perform a rotation process on all the pixels. Therefore, a storage area (buffer) for holding an enlarged image obtained by enlarging the original image information is required.

[Processing according to this embodiment]
FIG. 3 is a schematic diagram illustrating the concept of processing in the image processing apparatus according to the present embodiment. In the present embodiment, an inverse matrix M3 of a matrix for enlarging and rotating the original image information is generated, and the coordinates of the original image information are obtained from the coordinates of the converted image information using the inverse matrix M3. Then, the pixel value at the coordinates of the obtained original image information is set as the pixel value at the corresponding coordinates of the converted image information. As a result, the pixel values after direct enlargement and rotation are developed in the storage means without holding the enlarged image.

<3. Image processing program>
FIG. 4 is a flowchart for explaining the image processing program according to the present embodiment. The image processing program according to the present embodiment includes steps executed by a computer. The computer includes a calculation unit that executes the image processing program according to the present embodiment, a storage unit that stores programs and various data, and an input / output unit. In addition to an electronic computer such as a personal computer, the computer may be incorporated in an electronic device capable of handling image information such as a printing apparatus, a copying apparatus, a video recording / reproducing apparatus, and a portable terminal. Further, the information processing program of the present embodiment is recorded on a recording medium such as a CD-ROM or distributed via a network.

  Here, in the description along the flowchart shown in FIG. 4, reference numerals not shown in the figure refer to FIG. 1. First, original image information is input by the input means 1 (step S101). Since the original image information is composed of, for example, a page description language, it is expanded on xy coordinates.

  Next, an inverse matrix is generated by the inverse matrix generation means 21 of the rotation means 2 (step S102). In the present embodiment, when the original image information is enlarged and rotated and developed on the xy coordinates of the storage unit 4, an inverse matrix of a matrix of coordinate transformation including the magnification and rotation components is generated.

  Next, the circumscribed rectangle coordinates are acquired by the circumscribed rectangle acquiring unit 22 of the rotating unit 2 (step S103). The circumscribed rectangle is a circumscribed rectangle on the xy coordinates of the storage unit 4 in the converted image information when the original image information is enlarged and rotated. For example, the corner coordinates of the circumscribed rectangle of the converted image information are acquired from the coordinates after conversion when the corner coordinates of the original image information are enlarged and rotated.

  Next, with respect to the acquired circumscribed rectangle, in the region (coordinates) inside the circumscribed rectangle, the coordinates corresponding to the region of the converted image information are extracted (step S104). This determination is made by the coordinate extraction means 23 of the rotation means 2. A flag is set for the coordinates within the circumscribed rectangle and within the converted image information area.

  Next, using the inverse matrix generated previously for the flagged coordinates (the circumscribed rectangle on the xy coordinates of the storage means 4 and in the converted image information area), the original image corresponding to the coordinates is used. The coordinates in the information are acquired (step S105). Then, the pixel value at the coordinates of the acquired original image information is duplicated (step S106). The processing in steps S105 to S106 is performed by the duplicating unit 3.

  The processing from step S105 to step S106 is performed for all the coordinates for which the flag has been set (step S107). When there is no next coordinate with the flag set (when inverse transformation and duplication have been completed for all the coordinates with the flag set), a process of expanding the copied pixel value to the storage means 4 is performed (step S109). This process is performed by the duplicating means 3. Note that the duplicating unit 3 may acquire the inverse transformation of the coordinates and the pixel value for each of the coordinates for which the flag has been set, and may develop the same into the storage unit 4 as it is.

<4. Specific example>
Next, a specific example of image processing in the image processing apparatus and the image processing program according to the present embodiment will be described.

[Translation component]
First, the calculation of the translation component accompanying the rotation process of the original image information will be described. FIG. 5 is a schematic diagram for explaining normal rotation and rotation with parallel movement. The example shown in FIG. 5A shows the state of normal rotation processing. Here, the original image information S is rotated around the origin O of the xy coordinates, and becomes converted image information S ′.

  On the other hand, the example shown in FIG. 5B shows the state of the rotation process with parallel movement. In this rotation process, the original image information S is rotated and translated in each of the xy directions, whereby the converted image information S ′ is arranged in the first quadrant of the xy axis.

  That is, as shown in FIG. 5A, when the original image information S is simply rotated using a rotation matrix, for example, the original image information S in the first quadrant is converted into the second quadrant or the second quadrant by the rotation angle. It moves to the 3rd quadrant and the 4th quadrant. Thus, after rotation, the images are rotated in the first quadrant by being translated in the x and y directions. As a result, rotation is performed within the circumscribed rectangle B-box with the xy axes as part of the sides.

  FIG. 6 is a schematic diagram for explaining the translation component calculation. In the example shown in FIG. 6A, the original image information S made up of a rectangle is arranged in the first quadrant of the xy axis. Corners other than the origin O of the original image information S are defined as coordinates (1), coordinates (2), and coordinates (3), respectively.

  When the original image information S is rotated by a simple rotation matrix M2, the original image information S is rotated around the origin O of the xy axis, and post-conversion image information S 'as shown in FIG. 6B is obtained. At this time, the coordinates (1 ′), coordinates (2 ′), and coordinates (3 ′) after the rotation of the coordinates (1), coordinates (2), and coordinates (3), which are corners of the original image information S, are used. ).

  In order to calculate the translation component, attention is paid to the coordinates of the minimum values in the x and y directions among the coordinates of the converted image information S ′. In the example shown in FIG. 6B, attention is paid to the coordinate (1 ') having the minimum value in the x direction and the coordinate (2') having the minimum value in the y direction.

  Then, the absolute value of the x coordinate of the coordinate (1 ') is the translation component in the x direction, and the absolute value for the y-seat of the coordinate (2') is the translation component of the y direction. FIG. 7 is a schematic diagram showing a parallel movement component. As shown in FIG. 7A, when the original image information S is rotationally moved by the rotation matrix M2, it becomes converted image information S ′ as shown in FIG. 7B. The absolute value g of the x coordinate of the coordinate (1 ′) of the converted image information S ′ corresponding to the coordinate (1) of the original image information S becomes a translation component in the x direction, and the coordinate (2) of the original image information S The absolute value h of the y coordinate of the coordinate (2 ′) of the post-conversion image information S ′ corresponding to is the translation component in the y direction.

[Matrix of enlargement / rotation / translation]
As described above, after calculating the translation components g and h, an expansion and rotation matrix including the translation components is obtained. That is, a 2 × 2 matrix that is a composite matrix of the expanded matrix M1 and the rotation matrix M2 shown in FIG. A 3 × 3 matrix obtained by adding the translational components g and h to the 2 × 2 matrix is defined as Equation 2. Here, x and y are coordinates on the xy axis of the original image information, and x ′ and y ′ are coordinates on the xy axis of the converted image information. In the present embodiment, only a, b, c, d, g, and h are extracted from the components of the 3 × 3 matrix shown in Equation 2, and a 3 × 2 matrix as shown in Equation 3 is defined. This 3 × 2 matrix represents each component of enlargement, rotation, and translation of the original image information.

  Thereafter, a 3 × 2 inverse matrix for the 3 × 2 matrix of a, b, c, d, g, and h is generated by the inverse matrix generation means 21 shown in FIG.

[Get circumscribed rectangle and edge list]
Next, the circumscribed rectangle in the converted image information is acquired by the circumscribed rectangle acquiring unit 22 shown in FIG. The circumscribed rectangle uses a 3 × 2 matrix that expands, rotates, and translates the original image information, obtains the converted coordinates of the corners of the original image information, and follows the x-axis that passes through the coordinates of the uppermost and lowermost edges. A line surrounded by a line and a line along the y-axis passing through the leftmost and rightmost coordinates is obtained.
FIG. 8 is a schematic diagram for explaining a circumscribed rectangle and an edge list. As shown in the right diagram of FIG. 8, the circumscribed rectangle B-box of the converted image information S ′ that has been enlarged, rotated, and translated is acquired.

  Next, in the area inside the circumscribed rectangle B-box, coordinates that are within the area of the converted image information S ′ are obtained, and an edge list is constructed. The edge list is an information string that stores start coordinates and end coordinates for each line along the x-axis direction for the circumscribed rectangle B-box.

  As shown in FIG. 8, since the edge list has elements for each line along the x-axis direction of the circumscribed rectangle B-box, the edge list corresponds to the height (size in the y-axis direction) of the circumscribed rectangle B-box. It will have a corresponding number of elements. Each element is provided from the y coordinate y_0 to y_max of the circumscribed rectangle B-box.

  The value of each element is the x coordinate of the point that intersects the outer shape of the post-conversion image information S ′ for one line in the x-axis direction corresponding to the y-axis value. For example, the elements of the edge list corresponding to y_n are points SXn and EXn that intersect one line along the x-axis direction at the position of the y coordinate y_n and the outer shape of the converted image information S ′. That is, in one line along the x-axis direction on the y-axis y_n, it can be seen that the x-coordinates SXn to EXn are within the circumscribed rectangle B-box and within the region of the converted image information S ′. The edge list is generated by the coordinate extraction means 23 shown in FIG.

[Inverse transformation and pixel value replication by inverse matrix]
FIG. 9 is a schematic diagram for explaining the inverse transformation of coordinates by the inverse matrix and the duplication of pixel values. The inverse transformation of coordinates and the duplication of pixel values by this inverse matrix are performed by the duplicating means 3 shown in FIG. First, as shown in the right diagram of FIG. 9, the edge list (FIG. 8) previously obtained for the circumscribed rectangle B-box is sequentially referred to, and the coordinates of one element are inversely transformed from the start coordinate to the end coordinate by an inverse matrix. The coordinates corresponding to the original image information shown in the left diagram of FIG. 9 are obtained.

  Since the edge list is provided as an element for each y-coordinate, the y-coordinate is fixed, and each x-coordinate from the start coordinate to the end coordinate of the edge list is inversely transformed by an inverse matrix. As a result, the coordinates of the original image information S corresponding to the coordinates in the region of the converted image information S ′ are obtained.

  When the corresponding coordinates of the original image information S are obtained, the pixel value at the coordinates is obtained. This is copied in association with the coordinates before inverse transformation, that is, the coordinates of the transformed image information S ′. For example, in the edge list corresponding to y_n in the post-conversion image information S ′, if the coordinate value of the coordinates between the start coordinates SXn to EXn is (SXna, y_n), this coordinate is represented by a 3 × 2 inverse matrix. Reverse conversion by Thereby, the coordinates (xna, yna) of the original image information S are obtained. Then, the pixel value of the coordinates (xna, yna) is duplicated and associated with the coordinates (SXna, y_n) of the converted image information S ′.

  This process is performed from all start coordinates to end coordinates of the edge list. Then, the copied pixel value is developed in the storage unit 4.

  DESCRIPTION OF SYMBOLS 1 ... Input means, 2 ... Rotation means, 3 ... Duplication means, 4 ... Memory | storage means, 21 ... Inverse matrix production | generation means, 22 ... circumscribed rectangle acquisition means, 23 ... Coordinate extraction means

Claims (4)

an inverse matrix generation means for generating an inverse matrix of a matrix of coordinate transformation including the magnification and rotation components when expanding and rotating the original image information on the xy coordinates and expanding the original image information on the xy coordinates of the storage means;
Circumscribed rectangle obtaining means for obtaining coordinates corresponding to circumscribed rectangles on the xy coordinates of the storage means in the converted image information when the original image information is enlarged and rotated;
Coordinate extraction means for extracting coordinates that are within the area of the converted image information inside the circumscribed rectangle obtained by the circumscribed rectangle obtaining means;
With respect to the coordinates extracted by the coordinate extraction means, the coordinates corresponding to the original image information are obtained using the inverse matrix generated by the inverse matrix generation means, the pixel value of the obtained coordinates is obtained, and the obtained An image processing apparatus comprising: a duplicating unit that duplicates a pixel value to the extracted coordinates of the storage unit. The image processing apparatus according to claim 1, wherein the inverse matrix generation unit generates an inverse matrix of the coordinate conversion matrix including a translation component of the original image information. The translation component is used to match the minimum or maximum value of each of the x and y coordinates of the original image information with the minimum or maximum value of each of the x and y coordinates of the converted image information. The image processing apparatus according to claim 2, wherein the image processing apparatus includes an x-direction component and a y-direction component necessary for the image processing. an inverse matrix generation step for generating an inverse matrix of a matrix of coordinate transformation including the magnification and rotation components when executing image processing for expanding and rotating the original image information on the xy coordinates and expanding the original image information on the xy coordinates of the storage unit; ,
A circumscribed rectangle obtaining step for obtaining coordinates corresponding to circumscribed rectangles on the xy coordinates of the storage means in the converted image information when the original image information is enlarged and rotated;
A coordinate extraction step of extracting coordinates that are within the area of the converted image information inside the circumscribed rectangle obtained in the circumscribed rectangle obtaining step;
For the coordinates extracted in the coordinate extraction step, the coordinates corresponding to the original image information are obtained using the inverse matrix generated in the inverse matrix generation step, the pixel value of the obtained coordinates is obtained, and the obtained An image processing program that causes a computer to execute a duplication step of duplicating a pixel value to the extracted coordinates of the storage unit.

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