JP5483946B2 - Image processing apparatus, image processing apparatus control method, and program - Google Patents

Description

  The present invention relates to an image processing apparatus to which an external storage device can be connected.

  In recent years, removable external storage devices such as a USB memory and a memory card have been supplied to the market over a wide variety. An image processing apparatus capable of connecting such a removable external storage medium has been proposed (for example, Patent Reference 1).

JP 2008-28556 A

  However, these external storage devices vary greatly in performance, for example, writing speed, depending on products.

  For example, consider a case where image data generated by an image processing apparatus scanning a document is stored in an external storage medium such as a USB memory. In order to write image data to the USB memory, it is necessary to secure a buffer area in the main memory of the image processing apparatus. As described above, when the variation in the writing speed of the USB memory is large, the size of the buffer area to be secured varies depending on the type of the mounted USB memory. Therefore, it is conceivable to secure a sufficient write buffer in the main memory in consideration of variations in the writing speed of the USB memory. However, if this is done, the capacity of the program execution area and work area secured in the main memory will be reduced, and the performance of the image processing apparatus will be reduced. Although it is conceivable to increase the capacity of the main memory itself, the cost of the image processing apparatus increases.

  An object of the present invention is to provide an image processing apparatus capable of ensuring an appropriate buffer size according to the writing speed (transfer speed) of an attached external storage device.

The present invention has been made in view of the above problems, and an image processing apparatus according to the present invention transfers interface means for connecting to a removable storage device and a removable storage device connected to the interface means. Storage means including a first buffer area for storing image data to be stored; Transfer means for reading out image data stored in the first buffer area and transferring it to the removable storage apparatus; and the removable storage apparatus Specifying means for specifying the write-related capability; and first determining means for determining the size of the first buffer area of the storage means based on the write capability of the removable storage device specified by the specifying means; wherein the said removable storage device is further image data with respect to the transfer means has transferred the image data to the removable storage device When the response indicating that the image data cannot be received is made, the transfer means reduces the transfer speed of the image data to the removable storage device, and the first determining means is the first buffer area. the size, characterized that you determined to be a larger size.

  According to the present invention, it is possible to secure a buffer area of an appropriate size according to the writing speed of the connected external storage device.

It is a block diagram which shows an example of the hardware constitutions in the image processing apparatus of this embodiment. 6 is a flowchart illustrating an example of processing for storing image data generated by reading a document image in a USB memory in the image processing apparatus according to the present exemplary embodiment. 3 is a flowchart showing an example of processing for storing image data generated by reading a document image in a USB memory in the image processing apparatus of the present embodiment (continuation of FIG. 2). It is a flowchart which shows an example of the buffer capacity | capacitance determination process in the image processing apparatus of this embodiment. 6 is a flowchart illustrating an example of a USB memory speed measurement process in the image processing apparatus according to the present exemplary embodiment. It is a figure which shows an example of the memory map of DRAM in this embodiment. It is a figure which shows an example of BULK communication between the external device I / F part and USB memory in this embodiment.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

<Configuration of image processing apparatus>
FIG. 1 is a block diagram illustrating an example of a hardware configuration of an image processing apparatus according to the present embodiment. The image processing apparatus 40 according to the present embodiment is a composite image forming apparatus that includes a reading unit 406 that reads a document and a printer unit 405.

  The control unit 401 includes a CPU 400. The CPU 400 controls the entire image processing apparatus 40 by loading a program stored in the FLASH ROM 403 into the DRAM 402 and executing it. The DRAM 402 is used as an area for loading a program of the image processing apparatus 40, an area for temporarily storing image data, and a buffer area described later. The FLASH ROM 403 stores operation parameters of the image processing apparatus 40 or programs executed by the CPU 400. The power supply unit 404 supplies power to each unit of the image processing apparatus 40. The printer unit 405 prints out the image data transferred by the control unit 401.

  A reading unit 406 reads an original document under the control of the control unit 401, generates image data, and outputs the image data to the control unit 401. A network I / F unit 407 is an interface with the LAN 450. The operation display unit 408 outputs an operation input from the user to the control unit 401. The operation display unit 408 includes a display unit 409 and displays an operation screen. The external device I / F 410 is an interface with an external device, detects connection of the external storage device, supplies power to the external storage device, and performs data communication. In the present embodiment, it is assumed that the external device I / F 410 is a USB interface. The external device I / F 410 may be another type of interface, for example, an interface such as IEEE1394. The USB memory 411 is an example of an external storage device, and is connected to the image processing device 40 via the external device I / F unit 410. A USB device other than the USB memory 411 can be connected to the external device I / F 410.

  Next, processing for storing image data generated by the image processing apparatus 40 by reading a document in the USB memory 411 will be described.

<Memory Map of DRAM 402>
An area secured in the DRAM 402 will be described.

  FIG. 6 is a diagram showing an example of a memory map of the DRAM in the present embodiment.

  The program area 501 is an area for loading a program to be executed to control the CPU 400 image processing apparatus 40. After the image processing apparatus 40 is turned on, a program read from the FLASH ROM 403 is stored in this area. The work area 502 is an area used for temporarily storing image data when the CPU 400 performs image processing on the image data. A scan buffer area 503, which is an example of a second buffer area, is an area for temporarily storing image data in order to transfer the image data output from the reading unit 406 to the control unit 401. An accumulation buffer area 504, which is an example of a first buffer area, temporarily transfers image data transferred from the scan buffer area 503 to the control unit 401 and encoded in the control unit 401. The encoded image data read from the storage buffer area 504 is transferred to the USB memory 411 via the external device I / F 410. The USB memory 411 stores encoded image data transferred from the external device I / F 410. In the present embodiment, JPEG compression is used as an image data encoding method. The transfer image buffer area 505 is a transfer image buffer area for executing processing for transmitting image data stored in the USB memory to the outside via the network I / F unit 407.

<Process to scan original image and write to USB memory>
2 and 3 are flowcharts showing an example of processing for storing image data generated by reading a document image in the USB memory in the image processing apparatus of the present embodiment. This flowchart is realized by the CPU 400 of the image processing apparatus 40 executing a program stored in the FLASH ROM 403.

  In step S101, it is determined whether or not the USB memory 411 is connected to the external device I / F 410. If it is detected, the process proceeds to S102, and the writing speed of the connected USB memory 411 is measured. The details of this measurement process will be described in detail with reference to the flowchart of FIG.

  In step S103, various settings (resolution, reading mode, etc.) relating to image reading from the user of the image processing apparatus 40 are received via the operation display unit 408. In step S104, the buffer capacity to be secured in the DRAM 402 is determined. The details of the buffer capacity determination process will be described in detail with reference to the flowchart of FIG.

  When the buffer capacity is determined, the process proceeds to step S105, and the control unit 401 determines whether the scan buffer area 503 and the storage image buffer area 504 are equal to or smaller than the maximum allowable size. The allowable maximum size refers to each of the areas allocated to the storage image buffer 504 and the scan buffer area 503, which are areas obtained by subtracting the area already reserved for other uses or the work area 502 from the capacity of the DRAM 402. Size. In this embodiment, image data generated by reading a document is compressed by JPEG encoding processing. For example, assuming that the size of the compressed image data is 1/10 that of the uncompressed image data, the storage image buffer area 504 is allocated to be 1/10 of the read image buffer area. Therefore, 10/11 of the size of the remaining area is an allowable maximum size for the scan buffer area 503, and 1/11 of the size of the remaining area is an allowable maximum size for the storage image buffer area 504. If at least one of the scan buffer area 503 and the storage image buffer area 504 exceeds the allowable maximum size, the process proceeds to step S106. In this case, one page can be read without stopping the original reading operation based on a comparison between the writing speed to the mounted USB memory and the speed at which JPEG-compressed image data is stored in the storage image buffer area 504. The original image cannot be read. In step S106, a warning is displayed on the display unit 409 in the operation display unit 408, and this flowchart is terminated.

  On the other hand, if neither the scan buffer area 503 nor the storage image buffer area 504 exceeds the maximum allowable size, the process advances to step S107 to start a document reading operation. In step S108, the control unit 401 determines whether or not the remaining capacity in the scan buffer area 503 is equal to or greater than a predetermined first minimum value. As the first minimum value, a size is set such that if the remaining capacity of the scan buffer area 503 becomes smaller than that, a buffer overflow occurs and the original image cannot be read normally. If the remaining capacity is equal to or greater than the minimum value, the process proceeds to step S109, and if not, the process proceeds to step S110. In step S109, the control unit 401 determines whether the remaining capacity of the storage image buffer area 504 is equal to or greater than a predetermined second minimum value. As the second minimum value, a size is set such that if the remaining capacity of the storage image buffer area 504 becomes smaller than that, a buffer overflow occurs and the original image cannot be read normally. If the remaining capacity is equal to or greater than the minimum value, the process proceeds to step S112. Otherwise, it is determined that the reading operation is hindered, and the process proceeds to step S110.

  In step S112, while the image data is being transferred from the storage image buffer area 504 to the USB memory 411, the number of receptions (occurrence number) of a specific command, that is, “NAK” and “NYET” is less than the predetermined number. The control unit 401 determines whether or not there is. The occurrence of “NAK” and “NYET”, that is, a large number of handshakes indicates that the transfer rate (transfer speed) of image data to the USB memory is too high.

  Here, a procedure for writing data from the external device I / F unit 410 to the USB memory 411 will be described.

  FIG. 7 is a diagram illustrating an example of BULK communication between the external device I / F unit and the USB memory in the present embodiment. In the drawing, the left side is an external device I / F unit 410, and the right side is a USB memory 411.

  When image data is transferred from the external device I / F unit 410 to the USB memory 411, “OUT Token” is output from the external device I / F unit 410 to the USB memory 411 (601). Next, the external device I / F unit 410 outputs “DATA” to the USB memory 411 (602). In the present embodiment, “DATA” corresponds to image data obtained by reading a document and JPEG-compressing it. The USB memory 411 that has received “DATA” transmits “NYET” to the external device I / F unit 410 when it cannot receive further “DATA” (603). The external device I / F unit 410 that has received “NYET” transmits “PING”, which is a command for inquiring about the state of the USB memory 411 (604). If the USB memory 411 cannot receive further “DATA”, the USB memory 411 transmits “NAK” to the external device I / F unit 410 (605). Receiving “NAK”, the external device I / F unit 410 transmits “PING” again to the USB memory 411 (606). If the next “DATA” can be received, the USB memory 411 returns “ACK” to the external device I / F unit 410 (607). Receiving “ACK”, the external device I / F unit 410 transmits “OUT Token” for the next data transmission (608), and then transmits “DATA” (609). The USB memory 411 receives “DATA”, and transmits “ACK” to the external device I / F unit 410 if it can receive further “DATA”.

  Image data is transferred from the external device I / F unit 410 to the USB memory 411 in accordance with the above-described procedure example.

  Returning to the flowchart of FIG. If it is determined in S112 that the number of receptions (number of occurrences) of “NAK” and “NYET” is equal to or greater than the predetermined number, the data transfer rate between the external device I / F unit 410 and the USB memory 411 is too high. Is shown. In this case, the process proceeds to step S113, and the size of the storage image buffer area 504 to be secured is changed. Specifically, the size of the storage image buffer area 504 to be secured is enlarged. Then, the data transfer rate from the external device I / F unit 410 to the USB memory 411 is reduced. In the present embodiment, the size to be enlarged is an integer multiple of the data transfer size (8, 16, 32, 64 bytes or 512 bytes) to the USB memory 411. Then, since the data writing speed to the USB memory 411 is reduced by reducing the transfer rate of the external device I / F unit 410, the predetermined value used for the determination in step S109 is changed. Specifically, the value is changed to a smaller value. In step S114, the control unit 401 determines whether the changed size of the storage image buffer area 504 is equal to or smaller than the allowable maximum buffer size. If the size of the storage image buffer area 504 changed in step S113 is larger than the allowable maximum buffer size, the process proceeds to step S110. Otherwise, the process proceeds to step S115. In step S115, the control unit 401 confirms whether reading of one page of the document has been completed. When the reading of one page of the document is completed and it is determined that the document is in the residence, the process returns to step S107, and the next document is read. If it is determined that the reading of one page of the document has been completed, the process proceeds to step S116, and it is determined whether or not the size of the storage image buffer area 504 in one page has been changed. If it is determined that the size has been changed, the process proceeds to step S117, and document reading is temporarily stopped between pages. As a result, all the image data in the storage image buffer area 504 is transferred to the USB memory 411, and the storage image buffer area 504 is cleared. Thereafter, the process proceeds to step S118, and it is determined whether or not all pages of the document have been read. If it is determined that the process has been completed, this flowchart is terminated. If it is determined that the process has not been completed, the process returns to step S107 to read the next document.

  In step S110, the reading of the document is stopped, and the process proceeds to step S111, where a warning display indicating that the reading of the document is interrupted is displayed on the display unit 409. Note that after the reading is interrupted in step S110, it is possible to wait for the buffer area to become free and then resume the operation. By doing so, it is possible to complete the document reading process although the productivity is lowered.

  According to the flowcharts of FIGS. 2 and 3, by detecting the number of occurrences of “NAK” and “NYET”, it is possible to change the transfer rate to the optimum transfer rate according to the state of the USB memory 411.

  The image data of the original read by the reading unit 406 is stored in the USB memory 411 while performing the above buffer control. Furthermore, using the USB memory 411 as a buffer, the image data can be transferred to a PC (not shown) connected via the LAN 450. In this case, the image data read from the USB memory 411 is transferred to the transfer image buffer area 505 secured in the DRAM 402 via the external device I / F unit 410. The control unit 401 transfers the image data read from the transfer image buffer area 505 to the network I / F unit 407 and transmits the image to a PC (not shown) via the LAN 450.

  Next, the details of the USB memory speed measurement process, which is the process of step S102 of FIG. 2, will be described.

  FIG. 5 is a flowchart illustrating an example of a USB memory speed measurement process in the image processing apparatus according to the present embodiment.

  In step S301, the remaining capacity of the USB memory 411 is detected. In step S302, the data amount (size) of test data used for speed measurement of the USB memory 411 is determined from the remaining capacity. In step S303, writing of test data to the USB memory 411 is started. In step S304, the control unit 401 starts time measurement for writing speed measurement. In step S305, it is determined whether or not writing of test data has been completed. If it is determined that the writing has been completed, the process proceeds to step S306. In step S306, the control unit 401 ends the measurement of the test data write time.

  In step S307, reading of the test data written in the USB memory 411 is started. In step S308, the control unit 401 starts time measurement. In step S309, it is determined whether the test data reading is completed. If it is determined that the reading is completed, the process proceeds to step S310, and the reading time measurement is terminated.

  In step S311, the control unit 401 calculates the writing speed from the data amount of the test data and the measured writing time. In step S311, the control unit 401 calculates a reading speed from the data amount of the test data and the measured reading time. And this flowchart is complete | finished.

  In the flowchart of FIG. 5, both the writing speed and the reading speed are calculated as the capabilities of the USB memory 411. However, for example, only the writing speed may be calculated. In that case, the test data written in the USB memory 411 may be deleted without performing the processing of steps S307 to S310.

  Next, details of the buffer capacity determination process, which is the process of step S104 in FIG. 2, will be described.

  FIG. 4 is a flowchart illustrating an example of a buffer capacity determination process in the image processing apparatus according to the present embodiment.

  First, in step S201, the scan buffer area 503 is secured in accordance with the image reading setting set in step S103. In step S202, the speed (write speed) of the USB memory measured in step S102 is compared with the image data transfer speed after JPEG encoding transferred from the scan buffer area 503 to the storage image buffer area 504. If the speed of the USB memory is high (YES in step S202), the process proceeds to step S203, and a size corresponding to one page of image is secured from the DRAM 402 as an area of the storage image buffer area 504. The size of one page of image is set to a size that can store at least one page of image data after JPEG encoding that is predicted based on the setting related to document reading in the reading unit 406. On the other hand, if the speed of the USB memory is slow (NO in step S202), the process proceeds to S204, where {(storage image buffer input speed / USB memory speed) * image for one page is set as the storage image buffer area 504 area. } To ensure the size calculated from Here, the storage image buffer input speed is a speed at which JPEG-encoded image data is written in the storage image buffer area 504. In this embodiment, this speed is assumed to be equal to the speed at which JPEG-encoded image data is transferred to the storage image buffer area 504.

  As described above, according to the image processing apparatus of the present embodiment, it is possible to secure a buffer area having an optimal size according to the writing speed of the attached USB memory.

  In this embodiment, the USB memory is described as an example of the external storage device. However, the external storage device may be another removable storage medium, for example, various memory cards. In this case, the image processing apparatus 40 is provided with a memory card reader / writer instead of the external device I / F 410, and the memory card is attached to the memory card reader / writer.

  The present invention can also be realized by executing the following processing. That is, software (control program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads the program. To be executed. In this case, the program and the storage medium storing the program constitute the present invention.

40 Image forming apparatus 402 DRAM
406 Reading unit 410 External device I / F unit 411 USB memory 503 Scan buffer area 504 Storage image buffer area

Claims (7)

Interface means for connecting to a removable storage device;
Storage means including a first buffer area for storing image data to be transferred to a removable storage device connected to the interface means;
Transfer means for reading out the image data stored in the first buffer area and transferring it to the removable storage device;
Identifying means for identifying the ability of the removable storage device to write;
First determining means for determining the size of the first buffer area of the storage means based on the write capability of the removable storage device specified by the specifying means ;
When the transfer means makes a response indicating that the removable storage device cannot receive further image data in response to the transfer of the image data to the removable storage device, transfer means lowers the transfer rate of the image data to the removable storage device, the image first determination means, characterized that you determined to be larger than the size of the size of the first buffer area Processing equipment. The writing capability of the storage device is the writing speed of the removable storage device,
When the writing speed to the removable storage device is slower than the speed at which image data is written to the first buffer area, the first determining means sets the writing speed to the removable storage device to the first buffer area. The image processing apparatus according to claim 1, wherein the size of the first buffer area is determined so as to be larger than a case where the image data is written at a speed faster than that of the image data. A reading unit that reads the document and generates image data;
When the writing speed to the detachable storage device is higher than the speed at which image data is written to the first buffer area, the first determining means is configured to set the first buffer based on a setting relating to document reading in the reading means. The image processing apparatus according to claim 2, wherein a size of the area is determined. A reading unit that reads the document and generates image data;
The storage means further includes a second buffer area for storing image data generated by the reading means,
The image processing apparatus according to claim 1, further comprising second determination means for determining a size of the second buffer area.   When the first buffer area having the size determined by the first determining means and the second buffer area having the size determined by the second determining means cannot be secured in the storage means, the original by the reading means The image processing apparatus according to claim 4, further comprising a control unit configured to control the reading operation to be interrupted. A control method for an image processing apparatus, comprising: interface means for connecting to a removable storage device; and storage means including a buffer area for storing image data to be transferred to the removable storage device connected to the interface means. Because
A specific step of identifying the ability of the removable storage device to write;
A determination step of determining a size of the buffer area of the storage unit based on a writing capability of the removable storage device specified in the specification step;
A transfer step of reading the image data stored in the buffer area of the size determined in the determination step and transferring it to the removable storage device ,
When the response indicating that the removable storage device cannot receive further image data in response to the transfer of the image data to the removable storage device in the transfer step, control said in the transfer step removable to lower the transfer rate of the image data to the storage device, and wherein the be relocated so that the larger size the size of the determined the buffer region in the determination step Method. A control method for an image processing apparatus, comprising: interface means for connecting to a removable storage device; and storage means including a buffer area for storing image data to be transferred to the removable storage device connected to the interface means. A control program for executing
A specific step of identifying the ability of the removable storage device to write;
A determination step of determining a size of the buffer area of the storage unit based on a writing capability of the removable storage device specified in the specifying step;
A transfer step of reading the image data stored in the buffer area of the size determined in the determination step and transferring it to the removable storage device ,
When the response indicating that the removable storage device cannot receive further image data in response to the transfer of the image data to the removable storage device in the transfer step, control wherein in the transfer step removable to lower the transfer rate of the image data to the storage device, and wherein the be relocated so that the larger size the size of the buffer area determined in said determining step program.

Images