JP2010205143A - Image processing apparatus, inclination correction method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing apparatus, capable of suppressing even the increase in a required memory capacity, without causing marked deterioration in access efficiency to a DRAM, even if the skew angle becomes large, and to provide an inclination correction method and a program. <P>SOLUTION: The correction rotation angle of image data is acquired, a first address control system for performing address control of a storing part so as to read partial data of the predetermined number of blocks in an input buffer and a second address control system for performing address control of the storing part so as to occasionally read the partial data of a block in the input buffer are switched, according to the acquired correction rotation angle; rotation processing of the partial data written in the input buffer is performed; and address control of the storing part is performed so as to write the rotated partial data in an output buffer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, a tilt correction method, and a program.

  In a conventional image processing apparatus, an original area in an image read by an image reading apparatus such as a scanner is recognized, and tilt correction (deskew) and original area extraction (cropping) are performed efficiently.

  For example, in the technique described in Patent Document 1, an image is divided into a plurality of regions so that at least part of adjacent regions overlap each other, the divided regions are read out, a rotation process is performed, and parallel movement is performed based on the amount of movement. Techniques for performing are disclosed.

  Further, for example, in the technique disclosed in Patent Document 2, image data is stored in a large-capacity low-speed memory, and the image data is read out in units of blocks according to block read addresses and stored in a small-capacity high-speed memory. In this technique, further reading is performed in accordance with the read address for local rotation, and skew correction is performed. Furthermore, in this technique, in order to read out block by block in an oblique direction from the memory at an angle according to the inclination of the input image, the decimal part is approximated with a predetermined accuracy to sequentially generate an address for block writing, and There has been disclosed a technique for suppressing an accumulation error of an address for block reading due to approximation by increasing / decreasing a read address by a predetermined amount in a cycle according to accuracy.

  Further, for example, in the technique described in Patent Document 3, the reading buffer for storing the partial image is controlled, and the partial images stored in the reading buffer are sequentially converted into the output coordinate position, and the output coordinate position is set. A technique is disclosed in which matrix processing including rotation, scaling, and transformation is performed in units of blocks by controlling a writing buffer that stores a converted partial image.

Japanese Patent Publication No. 8-33919 JP 2005-352703 A JP 2008-192073 A

  However, in the conventional image processing apparatus (Patent Document 1 or the like), if the DRAM access efficiency is increased, the required buffer size increases (for example, the read image is square and the rotation angle is 45 degrees). In this case, the size of the input buffer is √2 times that of the output buffer).

  Also, the conventional image processing apparatus has a problem that the reading speed of the scanner is lowered because the access efficiency to the DRAM is greatly lowered as the skew angle is increased. That is, in the conventional image processing apparatus, the image is divided into blocks, read from the large-capacity low-speed memory to the high-speed memory, and the rotation process is performed in the block. There was a problem that the access efficiency to the low-speed memory was lowered. Here, a decrease in memory access efficiency will be described with reference to FIG. As shown in FIG. 1, it is necessary to continuously access a large-capacity low-speed memory when reading an image. However, in a conventional image processing apparatus, when the rotation angle is small, an input image access unit ( For example, since the ratio of deskew / cropping target documents (that is, interpolation targets) included in one raster) is large, the memory access efficiency is high, but when the rotation angle increases, the background (that is, other than the interpolation target) Since the ratio increases, there is a problem that the access efficiency of the memory is extremely lowered.

  The present invention has been made in view of the above problems, and an image processing apparatus capable of suppressing an increase in required memory capacity without causing a significant decrease in DRAM access efficiency even when the skew angle increases. An object of the present invention is to provide a tilt correction method and program.

  In order to achieve such an object, the image processing apparatus of the present invention includes at least a storage unit that stores image data read by the image reading device, and a control unit, and the image data is divided into block units. An image processing apparatus that corrects the inclination of the image data by dividing the data into pieces and performing rotation processing in units of the blocks, wherein the storage unit includes an input buffer and an output buffer, and the control unit includes: Rotation angle acquisition means for acquiring a corrected rotation angle of the image data, and the partial data of a predetermined number of blocks according to the correction rotation angle acquired by the rotation angle acquisition means so as to read the partial data into the input buffer. A first address control method for performing address control of the storage unit, and the storage unit to read the partial data of the block into the input buffer as needed Method switching control means for switching the second address control method for performing address control, rotation processing means for rotating the partial data written in the input buffer, and the partial data rotated by the rotation processing means Write control means for performing address control of the storage unit so as to write data into the output buffer.

  In the image processing apparatus of the present invention, in the above-described apparatus, the control unit further includes image compression means for performing data compression on the partial data rotated by the rotation processing means. Features.

  The image processing apparatus of the present invention is characterized in that, in the apparatus described above, the block size of the output buffer is 8 × 8 pixels, and the image compression means performs JPEG compression on the partial data. To do.

  In the image processing apparatus according to the present invention, in the apparatus described above, the writing control unit performs address control of the storage unit so that the partial data is overwritten on at least a part of the image data. Features.

  The image processing apparatus of the present invention is characterized in that, in the above-described apparatus, the input buffer stores at least a partial image of the partial data stored in the input buffer and / or coordinate information in the image data. And

  In addition, the tilt correction method of the present invention includes at least a storage unit that stores image data read by the image reading device and a control unit, and divides the image data into partial data in units of blocks. A tilt correction method executed in an image processing apparatus that performs tilt correction of the image data by performing rotation processing in units, wherein the storage unit includes an input buffer and an output buffer, and the control unit A rotation angle acquisition step of acquiring a correction rotation angle of the image data, and a predetermined number of blocks of the partial data according to the correction rotation angle acquired in the rotation angle acquisition step. A first address control method for controlling the address of the storage unit so as to read it into the input buffer, and the partial data of the block as the input A method switching control step for switching between a second address control method for performing address control of the storage unit so as to be read into the buffer as needed, a rotation processing step for rotating the partial data written in the input buffer, and the rotation A write control step of performing address control of the storage unit so as to write the partial data rotated by the processing step into the output buffer.

  The program of the present invention includes at least a storage unit that stores image data read by the image reading device and a control unit, and divides the image data into partial data in units of blocks, and in units of the blocks. A program for execution in an image processing apparatus that performs tilt correction of the image data by performing rotation processing, wherein the storage unit includes an input buffer and an output buffer, and the control unit includes According to the rotation angle acquisition step for acquiring the correction rotation angle of the image data and the correction rotation angle acquired in the rotation angle acquisition step, the partial data having a predetermined number of blocks is read into the input buffer. A first address control method for controlling the address of the storage unit, and the partial data of the block as the input buffer. A method switching control step for switching between a second address control method for performing address control of the storage unit so as to be read as needed, a rotation processing step for rotating the partial data written in the input buffer, and the rotation processing step And a write control step for performing address control of the storage unit so as to write the partial data rotated by step (a) to the output buffer.

  According to this invention, the first address for acquiring the correction rotation angle of the image data and performing address control of the storage unit so as to read the partial data of a predetermined number of blocks into the input buffer according to the acquired correction rotation angle. Switching between the control method and the second address control method for controlling the address of the storage unit so that partial data of the block is read into the input buffer at any time, the rotation processing of the partial data written in the input buffer is performed, and the rotated portion The address control of the storage unit can be performed so that data is written to the output buffer. Thereby, the present invention has an effect that processing can be performed while switching the usage of the small-capacity high-speed memory depending on the rotation angle. In addition, the present invention produces an effect that the burst length of the DRAM can be changed to an efficient length and access efficiency can be maintained. In addition, the present invention has an effect that the rotation process can be effectively performed in the inclination correction of several degrees. In addition, since the ratio of the input block to the output block is one-to-many, the present invention has an effect that the unit to be read at a time becomes longer and the number of accesses can be reduced. Further, according to the present invention, even if the skew angle becomes large, only a necessary part is cut out and stored in the input buffer, so that it is possible to relatively reduce wasteful reading without drastically reducing the access efficiency to the DRAM. There is an effect.

  Further, according to the present invention, data compression can be performed on the partial data that has been subjected to rotation processing. As a result, the present invention can reduce the data capacity, so that the memory area can be saved.

  In addition, according to the present invention, the block size of the output buffer is 8 × 8 pixels, and JPEG compression can be performed on the partial data. Thereby, this invention has the effect that it can apply to many apparatuses by using a highly versatile compression method.

  Further, according to the present invention, the address control of the storage unit can be performed so that the partial data is overwritten on at least a part of the image data. As a result, the present invention does not require separate memory areas for input and output, and has the effect of saving memory size.

  Further, according to the present invention, at least a partial image of partial data stored in the input buffer and / or coordinate information in the image data can be stored. As a result, the present invention has an effect that the reading order can be specified regardless of the input order of the images.

FIG. 1 is a conceptual diagram showing an example of access to a memory in the prior art. FIG. 2 is a schematic diagram illustrating an example of the configuration of the image processing apparatus. FIG. 3 is a block diagram showing an example of the configuration of an image processing apparatus to which the present invention is applied. FIG. 4 is a flowchart showing the inclination correction processing of the present invention. FIG. 5 is a schematic diagram illustrating an example of a method switching condition according to the correction rotation angle. FIG. 6 is a schematic diagram showing an example of reading partial data into the input buffer by the first address control method. FIG. 7 is an enlarged view of partial data according to the first address control method. FIG. 8 is a schematic diagram showing an example of reading partial data into the input buffer by the second address control method. FIG. 9 is a schematic diagram illustrating an example of the overwrite control performed in the present embodiment. FIG. 10 is a flowchart illustrating an example of the inclination correction process executed in the image processing apparatus 100 according to the present embodiment. FIG. 11 is a graph showing an example of DRAM access efficiency and measurement of required memory in the present embodiment and the prior art.

  Embodiments of an image processing apparatus, a tilt correction method, and a program according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

[Outline of the present invention]
The outline of the present invention will be described below with reference to FIG. 2, and then the configuration and processing of the present invention will be described in detail. FIG. 2 is a schematic diagram illustrating an example of the configuration of the image processing apparatus.

  The present invention generally has the following basic features. That is, the present invention includes at least a storage unit that stores image data read by the image reading device and a control unit, divides the image data into partial data in units of blocks, and performs rotation processing in units of the blocks. This is an image processing apparatus that corrects the inclination of image data.

  As shown in FIG. 2, image data (image data) read by an image reading apparatus such as a scanner is stored in a large-capacity low-speed memory of a storage unit. The image data stored in the large-capacity low-speed memory is generated by the control unit according to the address control of the storage unit that switches the method of reading into the small-capacity high-speed memory according to the corrected rotation angle acquired by the control unit. The image data (partial data) is read by the block read address and stored in the small-capacity high-speed memory. The image data (partial data) stored in the small-capacity high-speed memory is read according to the local rotation read address generated by the control unit, is subjected to rotation processing, and image compression is performed to save the memory size. Stored in large-capacity low-speed memory. Writing to the large-capacity low-speed memory is controlled according to the block write address generated by the control unit.

  This is the end of the description of the outline of the present invention.

[Configuration of Image Processing Apparatus 100]
Next, the configuration of the image processing apparatus 100 will be described with reference to FIG. FIG. 3 is a block diagram showing an example of the configuration of an image processing apparatus to which the present invention is applied, and conceptually shows only the portion related to the present invention.

  In FIG. 3, the image processing apparatus 100 schematically includes a control unit 102, an input / output control interface unit 108, and a storage unit 106. Here, the control unit 102 is a CPU or the like that comprehensively controls the entire image processing apparatus 100. The input / output control interface unit 108 is an interface connected to the image reading device 112. The storage unit 106 is a device that stores various databases and tables. Each unit of the image processing apparatus 100 is connected to be communicable via an arbitrary communication path.

  The storage unit 106 is a storage unit that stores a small-capacity high-speed memory such as a RAM (Random Access Memory) and a storage unit such as a large-capacity low-speed memory such as a hard disk or an SSD (Solid State Drive). An input buffer 106a is set for the high-speed memory, and an output buffer 106b is set for the large-capacity low-speed memory. Here, the input buffer 106a may store at least a partial image of partial data stored in the input buffer 106a and / or coordinate information in the image data. Further, the output buffer 106b may be set in a small-capacity high-speed memory separately from the input buffer 106a, or may be the same as the input buffer 106a.

  In FIG. 3, the input / output control interface unit 108 controls the image reading device 112. Here, as the image reading device 112, a scanner device, a digital camera, a WEB camera, or the like can be used.

  In FIG. 3, the control unit 102 includes an internal memory for storing a control program such as an OS (Operating System), a program defining various processing procedures, and necessary data. And the control part 102 performs the information processing for performing various processes by these programs. The control unit 102 includes a rotation angle acquisition unit 102a, a method switching control unit 102b, a rotation processing unit 102c, an image compression unit 102d, and a writing control unit 102e in terms of functional concept.

  Among these, the rotation angle acquisition unit 102a is a rotation angle acquisition unit that acquires a corrected rotation angle of image data read by the image reading device 112 and stored in the storage unit 106 (for example, a large-capacity low-speed memory).

  Further, the system switching control unit 102b performs first address control of the storage unit 106 so as to read partial data of a predetermined number of blocks into the input buffer 106a according to the corrected rotation angle acquired by the rotation angle acquisition unit 102a. It is a system switching control means for switching between an address control system and a second address control system that performs address control of the storage unit 106 so that partial data of a block is read into the input buffer 106a as needed.

  The rotation processing unit 102c is a rotation processing unit that performs a rotation process on the partial data written in the input buffer 106a.

  The image compression unit 102d is an image compression unit that performs data compression on the partial data rotated by the rotation processing unit 102c. Here, the image compression unit 102d may perform JPEG compression on the partial data by setting the block size to be output to the output buffer 106b to 8 × 8 pixels.

  The write control unit 102e is a write control unit that performs address control of the storage unit 106 so as to write partial data to the output buffer 106b. Here, the writing control unit 102e may perform address control of the storage unit 106 so that the partial data is overwritten on at least a part of the image data. This is the end of the description of the configuration of the image processing apparatus 100.

[Tilt correction processing]
Next, an example of the inclination correction process of the present invention will be described in detail with reference to FIGS. FIG. 4 is a flowchart showing an example of the inclination correction process of the present invention.

  As shown in FIG. 4, the image processing apparatus 100 acquires the corrected rotation angle of the image data stored in the storage unit 106 (step SA-1).

  Then, the image processing apparatus 100 controls the address of the storage unit 106 so as to read the partial data of a predetermined number of blocks into the input buffer 106a according to the corrected rotation angle acquired in step SA-1. Switching between the control method and the second address control method for controlling the address of the storage unit 106 so as to read the partial data of the block into the input buffer 106a as needed (step SA-2).

  Here, an example of the method switching control according to the correction rotation angle will be described with reference to FIGS. FIG. 5 is a schematic diagram illustrating an example of a method switching condition according to the correction rotation angle.

  As shown in FIG. 5, the method switching control unit 102b has an output block size of Nx × Ny, and a predetermined number of blocks (that is, the number of readings to the input buffer 106a) is M. Yes, when the correction rotation angle is θ, if the conditional expression: (Nxsinθ + Nycosθ)> (Nycosθ + MNxsinθ) is true, the first address control method is applied, while if the conditional expression is false, A two-address control method is applied.

  Here, an example of reading partial data into the input buffer 106a by the first address control method will be described with reference to FIGS. FIG. 6 is a schematic diagram showing an example of reading partial data into the input buffer 106a by the first address control method. FIG. 7 is an enlarged view of partial data according to the first address control method.

  As shown in FIG. 6, as an example, the method switching control unit 102b starts from the image data read by the image reading device 112 according to the output order (arrow), and the number of blocks M ( For example, the address control of the storage unit 106 is performed so that three pieces of partial data are read into the input buffer 106a (input buffer having a necessary height). Here, as shown in FIG. 7, for example, in the partial data (input block) read into the input buffer 106a, three output blocks predetermined by an efficient burst length are stored.

  An example of reading partial data into the input buffer 106a by the second address control method will be described with reference to FIG. FIG. 8 is a schematic diagram showing an example of reading partial data into the input buffer 106a by the second address control method.

  As shown in FIG. 8, as an example, the input block read into the input buffer 106 a includes a part of the output block, and from a large-capacity low-speed memory when necessary for processing (for example, rotation processing). Read from time to time.

  Returning to FIG. 4 again, the image processing apparatus 100 performs rotation processing on the partial data written in the input buffer 106a (step SA-3).

  Then, the image processing apparatus 100 performs address control of the storage unit 106 so as to write the partial data rotated in step SA-3 to the output buffer 106b (step SA-4).

  Here, the image processing apparatus 100 may perform address control of the storage unit 106 so that the partial data is overwritten on at least a part of the image data.

  An example of the overwrite control performed in the present embodiment will be described with reference to FIG. FIG. 9 is a schematic diagram illustrating an example of the overwrite control performed in the present embodiment.

  As shown in FIG. 9, as an example, the writing control unit 102 e performs a rotation process on partial data of image data (image data) to be deskewed / cropped stored in the storage unit 106, and the like. The image data (partial data) is overwritten on at least a part of the image data (for example, the background portion).

  Above, description of an example of the inclination correction process of this invention is finished.

[Example]
Next, an example of the inclination correction process executed in the image processing apparatus 100 according to the present embodiment configured as described above will be described in detail with reference to FIG. FIG. 10 is a flowchart illustrating an example of the inclination correction process executed in the image processing apparatus 100 according to the present embodiment.

  First, the system switching control unit 102b outputs a block size (for example, Nx in FIG. 5) at a time based on a skew angle (for example, θ in FIG. 5) and a predetermined number of blocks (for example, M in FIG. 5). × Ny), the output block size (B: for example, (Nycos θ + MNxsin θ) in FIG. 5) multiplied by the height of the input buffer 106a (A: for example, (Nxsin θ + Nycos θ) in FIG. 5) and the number of outputs (for example, M in FIG. 5). ) Is calculated (step SB-1).

  Then, the method switching control unit 102b determines whether or not A> B (step SB-2).

  When determining that A> B in Step SB-2 (Step SB-2: Yes), the method switching control unit 102b determines the height (B) of the input buffer 106a (Step SB-3). ).

  Then, the method switching control unit 102b generates an address (that is, a block read address) of the input buffer 106a according to the address control by the first address control method (step SB-4).

  Then, the method switching control unit 102b controls to read out the image data stored in the input buffer 106a from the storage unit 106 (for example, large-capacity low-speed memory) according to the address generated in step SB-4, The image data is read (step SB-5).

  Then, the rotation processing unit 102c performs local rotation processing from the corresponding portion of the input block written in the input buffer 106a in Step SB-5. Then, the write control unit 102e performs address control of the storage unit 106 so as to write partial data (output block) to the output buffer 106b, and outputs the output block (step SB-6).

  And the control part 102 determines whether the output of the frequency | count corresponding to the predetermined number of blocks (for example, M in FIG. 5) was implemented (step SB-7).

  If the control unit 102 does not determine that the number of times of output corresponding to the number of blocks determined in advance in step SB-7 has been performed (step SB-7: No), the control unit 102 shifts the processing to SB-5.

  On the other hand, when the control unit 102 determines that the number of times of output corresponding to the predetermined number of blocks has been performed in step SB-7 (step SB-7: Yes), the control unit 102e controls the storage unit 102e. It is determined whether or not all output blocks corresponding to the image data to be tilt corrected stored in 106 (for example, large-capacity low-speed memory) have been output to the output buffer 106b (step SB-8).

  If the control unit 102 determines in step SB-8 that all output blocks corresponding to the image data to be tilt corrected have not been output (step SB-8: No), the process proceeds to SB-4. Transition.

  On the other hand, if the control unit 102 determines in step SB-8 that all output blocks corresponding to the image data to be tilt corrected have been output to the output buffer 106b (step SB-8: Yes), the process ends. To do.

  Further, when it is determined in step SB-2 that A ≦ B is satisfied (step SB-2: No), the method switching control unit 102b has an address (i.e., an address necessary for outputting one block (that is, an output block)). That is, a block read address) is generated (step SB-9).

  Then, the control unit 102 includes at least a part of an image and / or image data of a tag indicating an address stored in the input buffer 106a (that is, an input block (that is, partial data) stored in the input buffer 106a). (Coordinate information) is checked (step SB-10).

  Based on the check performed in step SB-10, the control unit 102 determines whether or not the input buffer 106a is insufficient to store the input block necessary for configuring the output block ( Step SB-11).

  Then, the method switching control unit 102b determines in step SB-11 that the input buffer 106a does not have enough input blocks to be stored in the input buffer 106a (step SB-11: Yes). ), In accordance with the address generated in step SB-9, control is performed so that the partial data (input block) that is insufficient in the input buffer 106a is read from the storage unit 106 (for example, large-capacity low-speed memory), Data is read (step SB-12).

  On the other hand, the rotation processing unit 102c determines in step SB-11 that the input buffer 106a does not have enough input blocks to be stored in the input buffer 106a (step SB-11: No). Alternatively, when partial data (input block) that is insufficient in the input buffer 106a is read in step SB-12, local rotation processing is performed from the corresponding portion of the input block written in the input buffer 106a. . Then, the write control unit 102e performs address control of the storage unit 106 so as to write partial data (output block) to the output buffer 106b, and outputs the output block (step SB-13).

  Then, the control unit 102 determines whether or not all output blocks corresponding to the image data targeted for tilt correction stored in the storage unit 106 (for example, a large-capacity low-speed memory) have been output under the control of the write control unit 102e. Determine (step SB-14).

  If the control unit 102 determines that all the output blocks corresponding to the image data to be tilt corrected have not been output to the output buffer 106b (step SB-14: No), the process proceeds to SB-9. Let

  On the other hand, if the control unit 102 determines in step SB-14 that all output blocks corresponding to the image data to be tilt corrected have been output to the output buffer 106b (step SB-14: Yes), the process ends. To do.

  This is the end of the description of the example of the inclination correction processing in the present embodiment. Here, the difference between the present embodiment and the prior art will be described with reference to FIG. FIG. 11 is a graph showing an example of DRAM access efficiency and measurement of required memory in the present embodiment and the prior art. FIG. 11A shows the DRAM access efficiency with respect to the large-capacity low-speed memory according to the skew angle when the unit for reading data at once (that is, the burst length of the DRAM) is 64 bytes. FIG. 11B shows a necessary memory corresponding to the skew angle when the unit for reading data at a time is 64 bytes. In addition, the three graphs of the prior art 2 show the output block size (for example, Nx / Ny in FIG. 5, and the prior art 2: 8/8 in FIG. 11 shows an output block of 8 bytes × 8 bytes. The result by the difference is.

  As shown in FIG. 11, in the prior art 1, when the skew angle is small, the DRAM access efficiency is the best, but with a slight increase in the skew angle, the DRAM access efficiency rapidly decreases (FIG. 11A) and the memory However, a large constant value was required (FIG. 11B). Further, in the conventional technique 2, when the output block size is small (conventional technique 2: 8/8, conventional technique 2: 16/16 in FIG. 11B), the required memory can be suppressed to a small size. Since it is necessary to increase the number of accesses, the DRAM access efficiency is low regardless of the skew angle (FIG. 11A). Further, in the conventional technique 2, when the output block size is large (conventional technique 2: 32/32 in FIG. 11B), even when the skew angle is large, the decrease in DRAM access efficiency can be suppressed to a small level (FIG. 11A). Even when the skew angle is small, a large memory size is required, and the memory size is also required in proportion to the skew angle (FIG. 11B). On the other hand, in this method, since the method of using the input buffer is changed according to the skew angle (near the skew angle of 9 degrees in FIG. 11), the required memory size is maintained while maintaining the DRAM access efficiency to some extent (FIG. 11A). An image processing apparatus that can be suppressed (FIG. 11B) can be provided.

[Other embodiments]
Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, but can be applied to various different embodiments within the scope of the technical idea described in the claims. It may be implemented.

  For example, the case where the image processing apparatus 100 performs processing in a stand-alone form has been described as an example. However, processing is performed in response to a request from a client terminal configured with a separate housing from the image processing apparatus 100, and the processing is performed. You may comprise so that a result may be returned to the said client terminal.

  In addition, among the processes described in the embodiment, all or part of the processes described as being automatically performed can be performed manually, or the processes described as being performed manually can be performed. All or a part can be automatically performed by a known method.

  In addition, unless otherwise specified, the processing procedures, control procedures, specific names, information including registration data for each processing, parameters such as search conditions, screen examples, and database configurations shown in the above documents and drawings Can be changed arbitrarily.

  Further, regarding the image processing apparatus 100, each illustrated component is functionally conceptual and does not necessarily need to be physically configured as illustrated.

  For example, the processing functions provided in each device of the image processing apparatus 100, in particular, the processing functions performed by the control unit 102, all or any part thereof are interpreted and executed by a CPU (Central Processing Unit) and the CPU. It may be realized by a program to be executed, or may be realized as hardware by wired logic. The program is recorded on a recording medium to be described later, and is mechanically read by the image processing apparatus 100 as necessary. That is, the storage unit 106 such as a ROM or HD stores a computer program for performing various processes by giving instructions to the CPU in cooperation with an OS (Operating System). This computer program is executed by being loaded into the RAM, and constitutes the control unit 102 in cooperation with the CPU.

  The computer program may be stored in an application program server connected to the image processing apparatus 100 via an arbitrary network, and may be downloaded in whole or in part as necessary. is there.

  The program according to the present invention can also be stored in a computer-readable recording medium. Here, the “recording medium” is an arbitrary “portable physical medium” such as a flexible disk, a magneto-optical disk, a ROM, an EPROM, an EEPROM, a CD-ROM, an MO, a DVD, a Blu-ray Disc, or the like. It includes a “communication medium” that holds a program in a short period of time, such as a communication line or a carrier wave when a program is transmitted via a network represented by a LAN, WAN, or the Internet.

  The “program” is a data processing method described in an arbitrary language or description method, and may be in any format such as source code or binary code. Note that the “program” is not necessarily limited to a single configuration, and functions are achieved in cooperation with a separate configuration such as a plurality of modules and libraries or a separate program represented by the OS. Including things. Note that a well-known configuration and procedure can be used for a specific configuration for reading a recording medium, a reading procedure, an installation procedure after reading, and the like in each device described in the embodiment.

  The various databases and the like stored in the storage unit 106 are memory devices such as RAM, SSD, and ROM, fixed disk devices such as hard disks, and storage means such as flexible disks and optical disks. Stores programs, tables, databases, web page files, etc.

  In addition, the image processing apparatus 100 connects an information processing apparatus such as a known personal computer or workstation, and implements software (including programs, data, and the like) that realizes the method of the present invention in the information processing apparatus. It may be realized.

  Furthermore, the specific form of distribution / integration of the devices is not limited to that shown in the figure, and all or a part of them may be functional or physical in arbitrary units according to various additions or according to functional loads. Can be distributed and integrated.

  As described above in detail, according to the present invention, even if the skew angle increases, the image processing apparatus capable of suppressing an increase in the required memory capacity without significantly reducing the access efficiency to the DRAM, An inclination correction method and a program can be provided, and is particularly useful when implemented in the field of image processing relating to an image read by a scanner.

DESCRIPTION OF SYMBOLS 100 Image processing apparatus 102 Control part
102a Rotation angle acquisition unit
102b Method switching control unit
102c Rotation processing unit
102d Image compression unit
102e Write control unit 106 Storage unit
106a Input buffer
106b Output buffer 108 Input / output control interface unit 112 Image reading device

Claims (7)

By including at least a storage unit that stores image data read by the image reading device and a control unit, dividing the image data into partial data in units of blocks, and performing rotation processing in units of the blocks, An image processing apparatus for correcting inclination of image data,
The storage unit includes an input buffer and an output buffer,
The control unit
Rotation angle acquisition means for acquiring a corrected rotation angle of the image data;
A first address control method for performing address control of the storage unit so as to read a predetermined number of blocks of the partial data into the input buffer according to the correction rotation angle acquired by the rotation angle acquisition means; and the block System switching control means for switching between a second address control system for performing address control of the storage unit so as to read the partial data in the input buffer as needed.
Rotation processing means for performing rotation processing of the partial data written in the input buffer;
Write control means for performing address control of the storage unit so as to write the partial data rotated by the rotation processing means to the output buffer;
An image processing apparatus comprising: The image processing apparatus according to claim 1.
The control unit
Image compression means for performing data compression on the partial data rotated by the rotation processing means;
An image processing apparatus further comprising: The image processing apparatus according to claim 2,
The block size of the output buffer is 8 × 8 pixels,
An image processing apparatus, wherein the image compression means performs JPEG compression on the partial data. The image processing apparatus according to any one of claims 1 to 3,
The write control means includes
An image processing apparatus, wherein address control of the storage unit is performed so that the partial data is overwritten on at least a part of the image data. In the image processing device according to any one of claims 1 to 4,
The input buffer is
An image processing apparatus that stores at least a partial image of the partial data stored in the input buffer and / or coordinate information in the image data. By including at least a storage unit that stores image data read by the image reading device and a control unit, dividing the image data into partial data in units of blocks, and performing rotation processing in units of the blocks, A tilt correction method executed in an image processing apparatus that performs tilt correction of image data,
The storage unit includes an input buffer and an output buffer,
Executed in the control unit,
A rotation angle acquisition step of acquiring a correction rotation angle of the image data;
A first address control method for performing address control of the storage unit so as to read the partial data of a predetermined number of blocks into the input buffer according to the correction rotation angle acquired in the rotation angle acquisition step; A method switching control step for switching between a second address control method for performing address control of the storage unit so that the partial data of the block is read into the input buffer as needed;
A rotation processing step for rotating the partial data written in the input buffer;
A write control step for performing address control of the storage unit so as to write the partial data rotated by the rotation processing step to the output buffer;
A tilt correction method comprising: By including at least a storage unit that stores image data read by the image reading device and a control unit, dividing the image data into partial data in units of blocks, and performing rotation processing in units of the blocks, A program for execution in an image processing apparatus that performs inclination correction of image data,
The storage unit includes an input buffer and an output buffer,
In the control unit,
A rotation angle acquisition step of acquiring a correction rotation angle of the image data;
A first address control method for performing address control of the storage unit so as to read the partial data of a predetermined number of blocks into the input buffer according to the correction rotation angle acquired in the rotation angle acquisition step; A method switching control step for switching between a second address control method for performing address control of the storage unit so that the partial data of the block is read into the input buffer as needed;
A rotation processing step for rotating the partial data written in the input buffer;
A write control step for performing address control of the storage unit so as to write the partial data rotated by the rotation processing step to the output buffer;
A program for running

Images