JPH11341003A - Image processing system, information processor, controlling method, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute high speed transfer in the case of checking the contents of an image from an image scanner or an image data generation source and to prevent the layout of the whole image from being influenced by an error generated in transfer. SOLUTION: An image reader is connected to a host computer through, for example, an IEEE1394 interface. When an error occurs (S138) during the transfer of image data read out by the image reader in an isochronous transfer mode to the host computer as a packet, dummy data '0' for the size of the packet are prepared and handled as normally received data (S141).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing system, an information processing apparatus, a control method, and a storage medium for transferring image data at the time of prescan to a receiving node such as a host PC.

[0002]

2. Description of the Related Art Conventionally, there are the following methods and procedures for reading an image with an image scanner and transferring the read image data to a host PC or the like.

First, in order to know the whole image to be input, for example, it is determined whether or not the image to be read is the image to be read, or the reading range is specified and the color and density are adjusted. For this purpose, an image is scanned once (pre-scan) as a previous step. This prescanned image data is transmitted to a device that needs the image data, such as a host PC, where it is necessary to confirm the image and specify the area (trimming range specification) and color / density required when actually reading it as a main scan. Correction of. Then, a desired area is scanned (main scan) based on the pre-scan image, and the image is read again.

The pre-scan operation is performed before the main scan because it takes a long time to read and process the image by the main scan, so that a capture range is specified in advance so that desired image data can be obtained in one main scan. And colors
This is because it is necessary to make adjustments such as correction of density. If the specified area or color / density is not the intended one, the prescan operation is repeated to confirm them again after setting correction.

[0005] This pre-scan operation is necessary before reading desired image data in the main scan.
What is originally required is image data at the time of the main scan.
However, the time required for a series of operations, especially the data transfer time to a receiving node such as a host PC, cannot be ignored due to the large amount of image data to be read despite prescanning.

As a method of solving the above problem, that is, to reduce the time required for prescan, the reading resolution at the time of prescan is made lower than at the time of main scan, that is, image input is performed at a low resolution, or resolution conversion is performed at the time of transfer. Or compressing data at the time of reading, storing, or transmitting. Also, when reading a color image, if the user requests positional information of the document, the prescan image is read as a monochrome image, or the read color image is converted to a monochrome image and then transmitted. There is a method such as using a high-speed interface that has recently attracted attention.

[0007] These methods are similar in terms of how to reduce the amount of prescanned image data to be transmitted. Once the data to be transmitted is determined, it is necessary to guarantee the data so that the host can always receive it. Therefore, transfer processing takes longer than necessary due to error checking and retransmission procedures. In addition, USB (Universal Serial Bus) and IEE
Even when using a bus interface that has multiple transfer modes and is scheduled at fixed intervals, such as E1394,
The bandwidth of each transfer mode is allocated in one cycle (one frame). Bulk transfer (USB) and asynchronous transfer (IEEE1394) used to transfer a large amount of data such as image data read from a scanner When the bus traffic is large (when other high-priority transfer such as isochronous transfer is frequently performed), the data transmission should be performed at a desired transfer rate because the priority is lower than other transfer. Can not.

Therefore, a method of shortening the total transmission processing time by using a transfer mode (isochronous transfer) for guaranteeing a fixed band, which is a feature of these interfaces, for transmitting prescanned image data can be considered.

As an interface supporting the isochronous transfer mode, a USB (UniversalSerial) which is a serial interface for connecting a computer and a peripheral device is used.
rialBus) and IEEE 1394, which is a high-speed serial interface that does not require a host computer at a higher speed, and the like, will be briefly described here.

[0010] USB is a bus interface that can connect computers and peripheral devices at a communication speed of 12 Mbps at a relatively low cost (a low-speed communication speed of 1.5 Mbps can coexist). A PC is always required as a host, but it has functions such as a star topology configuration, hot plug-in (hot plugging and unplugging), and plug and play, and many peripheral devices compatible with USB are also being commercialized.

[0011] IEEE1394 is capable of high-speed transmission of large-capacity data such as moving images, capable of memory access by a bus architecture, capable of hot plug-in or plug-and-play, and of peer-to- Due to its features such as the possibility of peer connection, application to not only PCs but also household devices (AV devices such as digital video cameras) at home has been actively promoted. Currently the transfer speed is standardized up to 400Mbps,
Formulation of new standards for higher speeds and longer distances is also being actively pursued.

A feature of both USB and IEEE1394 is a transfer mode that guarantees a fixed band called isochronous transfer and does not perform retransmission even if an error occurs. Here, an example of the bus configuration and the bandwidth (bandwidth) will be described using USB as an example.

FIG. 23 shows an example of a USB connection configuration. In the figure, 1401 is a host, 1402 is a hub, and 1403 is a device.

The host 1601 is usually a computer (for example, a personal computer) and controls communication over the entire USB. The hub 1602 is a branch point of the USB connection, and can connect a plurality of other hubs and devices (host
The 1601 also has a hub function called the root hub.) The device 1603 is a peripheral device such as a keyboard, a modem, a printer, and a scanner.

USB transfer modes include control transfer, isochronous transfer, interrupt transfer, and bulk transfer. The control transfer is a transfer used for controlling the USB. The isochronous transfer is a transfer in which a delay is not allowed at a fixed speed, that is, a transfer that guarantees a fixed band but does not perform retransmission even when an error occurs. (For example, it is used when transferring audio data such as telephones and audio, and moving image data such as video.)
Since the transfer speed is not so high as compared with EEE1394, it is considered that it is not suitable for transferring moving image data. The interrupt transfer is a transfer that requires a quick response time (for example, used for a pointing device such as a keyboard and a mouse, a joystick, and the like). Bulk transfer is a transfer with a large amount of data but low priority. (For example, it is used for a printer and a scanner.) FIG. 24 shows an example of a USB bandwidth. In the figure, 170
1 to 1704 are frames that occur repeatedly. 1705
Is an SOF (Start Of Frame) packet indicating the start of a frame. Reference numerals 1706 to 1708 denote bandwidths of the isochronous transfer. 1706 is a telephone, 1707 is a speaker, 1708 is a modem, and in this case, a device handling voice uses this band. 1709 is the interrupt transfer bandwidth used by the keyboard device. 1710 is the bulk transfer bandwidth used by the scanner device. 1711
Is the unused bandwidth.

Here, the frame is generated in the USB 1
This is the bandwidth of the ms cycle. The bandwidth of each transfer mode is secured in one frame. The bandwidth of the isochronous transfer is allocated when a device using this transfer mode is connected to the USB, and thereafter a constant bandwidth is maintained unless the bus topology is changed or reset. Bulk transfer uses extra bandwidth not used in other transfer modes such as isochronous transfer. Therefore, if the bandwidth used in the isochronous transfer or the like is large, the capacity of the bulk transfer is reduced. In particular, the isochronous transfer has a large influence because a fixed band is secured.

Although examples of IEEE1394 are not given here, the transfer modes include isochronous transfer and asynchronous transfer (bulk transfer in USB), the band for isochronous transfer is guaranteed, and the remaining band for asynchronous transfer is used. It is the same as USB.

[0018]

However, in the above conventional example, since the prescanned image data is transmitted by isochronous transfer without a retransmission procedure, there is a problem that when an error occurs, the image data is lost.

This example will be described with reference to FIG.

FIGS. 25A and 25C are schematic diagrams of image data read by pre-scanning. The image data is divided so as to fit in the size of the transmission packet and transferred to the receiving side. FIG. 7A shows a case where the band is divided in the sub-scanning direction, and FIG. 7C shows a case where the band is divided into blocks in both the main scanning and the sub-scanning. The numbers (1 to 12) shown in FIG. 3A are used to identify each divided band. Also, the numbers and alphabets in FIG. 3C are shown to identify the blocks.

In each of the figures, the band (5) or the block (3b) highlighted by a halftone dot is a packet that could not be received due to an error during isochronous transfer. When there is no recovery procedure, the display of the prescanned image data on the receiving side is as shown in FIGS.

In either case, since the band or the block is missing, the image is shifted accordingly. For example, in the case of FIG. 7B, the band 6 comes where the band 5 should originally come, and thereafter it shifts by one. The total number of packets to be received is also reduced by one. Also, in the case of FIG.
Block 3c comes to the place where is to be displayed and shifts one by one thereafter. Here also, the total number of received packets is reduced by one. As described above, the missing packet makes it difficult to grasp the position information of the target image in the original prescan.

In order to solve this problem, a transfer mode for ensuring reliable data transfer in the event of a data error or when a packet cannot be received is employed, and a method of transmitting missing image data again, or A method of retransmitting by isochronous transfer is conceivable. However, if it is not possible to determine which image data has been lost, retransmission is performed from the beginning and it takes time.

Even if a lost packet can be specified, it takes a certain amount of time to process the retransmission procedure, and if an isochronous transfer is used for retransmission, the retransmission procedure must be performed again when an error occurs. Come out. Further, if asynchronous transfer is used, which has a lower priority in band use than isochronous transfer in order to perform reliable retransmission, it takes more time.

[0025]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a first object of the present invention is to perform high-speed transfer when confirming the content of an image from, for example, an image scanner or an image data source. Let it be done, and
It is an object of the present invention to provide an image processing system, an information processing apparatus, a control method, and a storage medium that can eliminate the influence on the layout of the entire image even if an error occurs during transfer.

A second object is to cause a high-speed transfer of an image read by an image scanner or the like or image data of an image data source, and that an error occurs even if an error occurs during the transfer. By transferring only the transferred data in the transfer mode with the retransmission procedure,
It is an object of the present invention to provide an image processing system, an information processing apparatus, a control method, and a storage medium that can guarantee both high-speed transfer and image quality.

The image processing system of the present invention, which achieves the first object among the above objects, has the following configuration. That is, in an image processing system including an image reading device and an information processing device connected via a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs, A determination unit configured to determine whether an error has occurred in receiving a data packet from the image reading device using the first transfer mode during pre-scanning of a document image; Means for generating dummy data corresponding to the data size of the error packet without requesting retransmission of the data packet in which the error has occurred if the means determines that an error has occurred. An image is constructed based on the received data and the dummy data.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First Embodiment> FIG. 6 is a block diagram showing the configuration of an image reading system according to the first embodiment.

In the figure, reference numeral 201 denotes an image reading apparatus main body. It is composed of blocks 202 to 212 described below,
It has a scanner function for reading an original, an image processing function, and a communication function for transmitting image data.

Reference numeral 202 denotes control of the entire image reading apparatus 201 and
It is a CPU that executes programs for realizing the functions of the transaction layer, node controller, and application layer of the IEEE1394 interface. 203
Is a ROM that stores programs executed by the CPU 202 and various control information. As the ROM 203, for example, a flash memory or the like can be used to update the control information later.

Reference numeral 204 denotes a RAM that stores data and programs used by the CPU 202, various image data read by the scanner unit 205, and created correction data.

Reference numeral 205 denotes a scanner unit for reading a document, which includes a light source for reading the document, a CCD sensor, an A / D converter, an image signal correction circuit, and the like. Details will be described later with reference to FIG.

An ASIC 206 performs mechanical control (not shown) and various image processing in the image reading apparatus. It is a dedicated hardware logic for performing various kinds of image processing such as control of a scanner head when reading an image, correction of read image data, compression encoding, and parameter extraction.

Reference numeral 207 denotes a correction data creation unit in the ASIC 206, details of the processing contents and the like will be described later with reference to FIG. 208
Is a block for extracting parameters for creating correction data in the ASIC 206. 209 is ASIC206
Is an image processing unit that performs various image processing.

Reference numeral 210 denotes a user interface for notifying the user of the status of the image reading apparatus 201 and communication, and for accepting a command input from the user. The user interface 210 includes a display unit for notifying and an operation unit for accepting the input. Is done.

Reference numeral 211 denotes an IEEE 139 for controlling IEEE 1394 communication.
4 PHY (physical) layer and L
It is composed of a dedicated LSI having the function of each layer of the INK layer. Details will be described later with reference to FIG.

Reference numeral 212 denotes a system bus. In addition to the constituent blocks 202 to 211 of the illustrated image reading apparatus 201, constituent blocks (not shown) are also connected to this bus, and high-speed data transfer can be performed between the blocks. 213 is an IEEE1394 interface cable. In this cable, a total of six cables are crossed including two twisted pair cables (one is a signal line called A and the other is a signal line called B) and one set of a power supply pair cable.

Reference numeral 214 denotes a host computer (for example, a workstation or a personal computer). In this system configuration, the host computer 214 issues a reading request to the image reading device (scanner device) 201, and receives image data transferred from the image reading device (scanner device) 201. 215
Is an IEEE 1394 device control unit that controls IEEE 1394 communication, and has the same function as 211 described above. 216
Is a CPU that executes an application program which is one of the components of the system for controlling the host computer 214 and reading the scanner.

However, on the host computer 214, I
A program (driver) for realizing the functions of the transaction layer, the node controller, and the application layer of the EEE1394 interface is also executed.

A RAM 217 temporarily stores data and programs used by the CPU 216 and various image data transmitted from the scanner device 201, and is loaded with an OS as well as an application. 218
OS, application executed by the CPU 216,
And a hard disk drive for storing the above driver program, control information, and various image data. Reference numeral 219 denotes a system bus, and devices (not shown) are also connected to the system bus.

Reference numeral 220 denotes a display unit such as a CRT or LCD connected to the host computer 214. The display of the transmitted image data and the setting at the time of reading are displayed.

Reference numeral 221 denotes an operation unit including a pointing device such as a keyboard and a mouse connected to the host computer 214. Thus, operations on the application such as various reading settings are performed.

With the above system configuration, the image reading device 201 connected by the IEEE1394 interface executes the image reading requested by the host computer 214,
By sending the read image data to the host computer 214 via the same interface, a desired image can be obtained.

FIG. 7 shows a scanner unit 205 according to the first embodiment.
FIG. 2 is a block diagram showing the configuration of FIG. In the figure, 301 is a light source 3
02 is a drive unit for driving the scanner unit 205 including the CCD sensor 304 and the like. Reference numeral 302 denotes a light source, which includes an LED, a halogen lamp, and the like. Reference numeral 303 denotes a read original (or film). Reference numeral 304 denotes a sensor using a CCD. An A / D converter 305 converts an analog output signal from the CCD sensor 304 into a digital signal. Here, a 10-bit A / D converter is assumed.
Reference numeral 306 denotes an image signal correction circuit that corrects an input signal such as shading correction based on a digital signal of the A / D converter 305.

Scan control is performed by the CPU 202. The CPU 202 first outputs a signal to the driving unit 301 so that the scanner unit 205 scans the original 303, and thereafter, the reflected light from the original 303 that has received the light emitted from the light source 302 of the scanner detects the light. CCD sensor 3
The image information of the original 303 is detected by the A / D converter 3.
At 05, the digital signal is converted into a 10-bit RGB digital signal. Then, based on these signals, the image signal is corrected by an image signal correction circuit, the input level is corrected, and the CPU
202 outputs a signal to the drive unit 301 to control the operation of the scanner. At the final output stage, each color component is converted to 8 bits. By doing so, the accuracy of various conversions and correction processing inside the image reading apparatus is increased. If only the position information of the document is required, such as a pre-scan request, and the user is not required to obtain color information, a scanning operation is performed using only one color signal of the G component of the RGB components and output.

FIG. 8 shows the IEEE1394 in the first embodiment.
FIG. 3 is a block diagram illustrating a configuration of an interface control unit.

In the figure, reference numeral 401 denotes hardware logic of the physical layer of the physical layer and the link layer constituting the IEEE1394 interface control unit 211 of FIG. The PHY LSI 401 constituting the physical layer is composed of blocks 407, 408, and 412 to 414 described below. 402
Reference numerals a, 402b, and 402c denote receptacles serving as receptacles (ports) on the device body side of the IEEE1394 interface. Here, a cable for connecting to various other devices is inserted. In this embodiment, the device has three ports. Reference numeral 403 denotes a plug of the IEEE1394 interface cable. This part is inserted into the ports of various devices and connected. Reference numeral 404 denotes an IEEE1394 interface cable. In this cable, a total of six cables are crossed including two twisted pair cables (one is a signal line called A and the other is a signal line called B) and one set of a power supply pair cable. 405 is a TpA signal from the TpA receiver. The IEEE1394 device has two transceivers TpA and TpB for one port. TpA transmits an arbitration bit and a packet (strobe signal) and receives an arbitration signal and a packet (data signal).

Reference numeral 406 denotes a TpB signal from the TpB receiver. TpB transmits an arbitration bit and a packet (data signal) and receives an arbitration signal and a packet (strobe signal).

407a, 407b and 407c are transmitters and receivers comprising a driver for driving a differential signal, a low-offset wideband receiver, and a conversion unit to a digital signal. Here, a signal transmitted on the IEEE1394 cable is received, and data transmitted from the device is converted into a signal to be transmitted through the cable.

Reference numeral 408 denotes a PLL for generating a clock having an operating frequency of the IEEE1394 interface from the output of the crystal oscillator 409. 409 is a crystal oscillator. In 410, the operation clock of the IEEE1394 interface is supplied. 100Mbps to 400Mb depending on device
An operation clock of ps is required. Reference numeral 411 denotes a digital signal converted by the transmitter and the receiver 407. Various signals used in the configuration of the bus and data signals transmitted / received correspond thereto.

Reference numeral 412 denotes L for realizing a link layer function.
A control unit (control unit) that controls the interface with the SI, performs various controls at the time of bus initialization, loop detection, and bus reconfiguration. Reference numeral 413 denotes a DS-Link codec defined in the IEEE1394 interface specification. Reference numeral 414 denotes an interface with an LSI that implements a link layer function, and is configured by various registers. It sends data received through this interface and data to be sent to other devices.

Reference numeral 415 denotes hardware logic constituting a link layer among a physical layer and a link layer corresponding to a portion 211 in FIG. L that constitutes the link layer
The SI 415 is composed of blocks 416 to 423 described below.

Reference numeral 416 denotes L for realizing the function of the PHY layer.
This is the interface with the SI. 417 is a link core that implements the main functions of the link layer. Generation of a cycle timer and generation and reception of a CRC of a transmission packet required when this device has a function of a transmitter or an isochronous resource manager or more that converts transmission data in each transfer mode of isochronous and asynchronous into each packet format. It has a function such as a receiver for checking the CRC of the packet and the packet received from the PHY layer.

Reference numeral 418 denotes an LS for realizing the function of the physical layer
It is a control unit (control unit) that controls an interface with I and controls each function block included therein. Reference numeral 419 denotes a transmission / reception buffer dedicated to asynchronous transfer. This buffer 419 is a temporary buffer for absorbing the respective data transfer rates between the transmitter and the host bus. Reference numeral 420 denotes various registers for externally controlling the link LSI 415. Reference numeral 421 denotes an isochronous dedicated interface, which handles an external system via a dedicated bus. Reference numeral 422 denotes a host interface, which includes various registers. It is a connection point with a layer above the link layer (such as a transaction layer or an application layer). Reference numeral 423 denotes an interrupt control circuit for notifying an upper layer of an interrupt factor defined in the internal register. Notification of packet reception, occurrence of a bus reset, and the like.

FIG. 9 is a flowchart showing a control procedure on the image data transmitting side (the image reading apparatus in the embodiment) of the first embodiment.

First, in step S501, an image reading request from a user is received. This is requested from the host computer 214 operated by the user,
At the same time, various selection information for reading set on the host side is also transmitted. This image reading request must be sent from the host computer 214 to the image reading apparatus 201 without fail, so that if an error occurs, asynchronous transfer, which is a transfer mode for performing retransmission processing, is used.

In step S502, whether the reading of the image is pre-scan or not (main scan)
Is selected. Step S503 for pre-scan
If not, the process proceeds to step S505.

In step S503, a prescan process is performed. A detailed description is given in FIG.

In step S504, correction data to be used at the time of the main scan or at the time of performing the prescan operation again is created. A detailed description is given in FIG. Although the correction data is created after the pre-scan processing in the flowchart, even if the pre-scan processing is not completed, the correction data can be created when necessary data is obtained. Further, in this configuration, since this function is realized by hardware logic, it is possible to create correction data at the same time as the image data is read by the scanner device 205.

In step S505, a main scan operation is performed. A detailed description is given in FIG.

In step S506, it is determined whether the reading operation is performed again after the correction data creation processing S504 and the main scanning processing S505. Host computer
If there is a further reading request from 214, step S5
To 07, otherwise, end all processing at this stage.

In step S507, correction data creation processing S5
Using the data created in 04, it is determined whether to create correction data for the next reading. If the correction data created at the time of the pre-scan exists and the correction is performed, the process proceeds to step S508. If not, that is, if the image is read under the same reading conditions, the process proceeds to step S502 to repeat the reading process again.

In step S508, correction processing of the correction data is performed. This completes the change / correction of the correction data to be used if necessary at the time of the next reading, and stands by for the subsequent prescan or main scan processing.

FIG. 10 is a flowchart showing the procedure (step S503) of the pre-scan according to the first embodiment.

In step S601, the moving speed of the scanner is set. Since the scanner is assumed to be a line sensor, a desired resolution can be obtained by controlling the driving speed of the scanner device 302 in the sub-scanning direction.

In step S602, it is determined whether or not image data is to be corrected using the pre-scanning correction data. Step S when using the correction data
In step 603, the correction is set. Otherwise (when the default setting is kept), the process proceeds to step S604.

In step S603, correction data is set. Thus, the reading position and the input level of the document are set. If necessary, the color and density are set to be corrected.

When the processing proceeds to step S604, the driving unit 301
To start the movement of the scanner. Then, in step S605, an image is read. In addition, the image data read in parallel to the image data is transmitted to the host computer 214 and stored in a storage medium in the image reading apparatus 201. These processes may be performed serially, or may be performed in parallel depending on the configuration.

In step S606, it is determined whether the reading of the image has been completed. If the reading is completed, the process returns to step S609. If the reading is still being performed, the process returns to step S605 to continue the reading process.

In step S607, transmission processing for transferring the read image data to the host computer 214 is performed. Details will be described later with reference to FIG.

In step S608, a storage process for storing the read image data is performed. Details will be described later with reference to FIG.

In step S609, the scanner is stopped. As described above, the driving of the scanner is processed in parallel with the transmission to the host and the storage in the memory.

FIG. 11 is a flowchart showing the procedure of the transmission process according to the first embodiment.

First, in step S701, it is determined whether transmission of image data to the host computer 214 is possible. If communication with the host computer 214 is not possible, the process proceeds to step S702, and the user is notified via the user interface 210 of the image reading device 201 that image data cannot be transmitted to the host computer 214.

If transmission is possible, step S70
Proceed to 3. Here, it is determined whether or not to perform resolution conversion. If the resolution conversion process is to be performed here, step S70
Proceed to 4; otherwise, proceed to step S707.

In step S704, it is determined whether or not zero-order interpolation (simple thinning) is selected as the resolution conversion processing. Here, if the resolution conversion of the zero-order interpolation is performed, the process proceeds to step S705; otherwise (if another resolution conversion process is performed), the process proceeds to step S706.

In step S705, resolution conversion processing of 0-order interpolation (simple thinning) is performed.
The resolution conversion processing of the next interpolation (linear interpolation) is performed.

In step S707, it is determined whether to compress the image data to be transferred. If compression processing is to be performed, the process proceeds to step S708, where image data compression processing is performed.
If not performed, the process of step S708 is skipped, and the process proceeds to step S709.

In step S709, it is determined whether color information is necessary. When color information is required, it is necessary to always perform recovery processing such as a retransmission procedure when an error occurs. If color information is required, the process proceeds to step S711; otherwise, the process proceeds to step S710.

In step S710, a transfer process E of image data when color information is not required is performed. The processing content will be described later with reference to FIG.

In step S711, when color information is required, it is determined whether or not to use the isochronous transfer mode for transferring the image data. If the isochronous transfer mode is used, the process proceeds to step S713. If not, that is, if the asynchronous transfer mode is used, the process proceeds to step S712.

In step S712, processing F for performing image data transfer using asynchronous transfer is performed. The processing content will be described later with reference to FIG.

In step S713, processing G for performing image data transfer using isochronous transfer is performed. The processing content will be described later with reference to FIG.

When any of the transfer processes is completed, the process proceeds to step S714 to perform a procedure associated with the end of the transmission.

The transfer processing in step S710 when the color information is unnecessary is described with reference to FIG.

In step S715, a transmission packet size is set. Specifically, the size of the image data to be transmitted or the total number of packets to be transmitted, the size of the packet for one transfer, and the like are determined. Actually, since the transmission process is performed while reading, the image data size is a value expected from the read size. When determining the packet size, the packet size is determined such that a constant multiple of the data length of the prescan image to be displayed in the main scanning direction matches the data length of the packet to be transmitted. Alternatively, the packet size is determined so that a constant multiple of the data length of the set transmission packet matches the data length in the main scanning direction of the prescan image to be displayed.
It is set within the range not exceeding the isochronous transfer band allocated after the 1394 bus configuration.

In step S716, the transmission data information (image data size, total number of packets, and packet size) set in step S715 is transmitted to the host computer using asynchronous transfer in which an error is retransmitted.
Send to 214.

Next, in step S717, processing for transmitting the prescanned image data in the isochronous transfer mode is started.

In step S718, image data is transmitted to the host computer 214 for each packet by isochronous transfer. Then, in step S719, the process returns to step S718 to continue the transmission process until it is determined that all the image data has been transmitted.

Since the transfer uses the isochronous transfer, it is not actually necessary to count the number of packets that have been transmitted (or the number of remaining image data) each time one packet is transmitted. Further, even when all the packets have been transferred, there is no need to notify the host computer 214 of the fact. After the transfer is completed, no packet is transmitted, but the band allocated for isochronous transfer remains unchanged.

The feature of the process E is that the isochronous transfer mode without the retransmission procedure is used for the transfer of the prescan image. By this, a fixed band is always maintained after the band for the isochronous transfer is secured in the IEEE1394 bus configuration. Can be used because host computer 21
It becomes possible to shorten the processing time for transferring the image to the fourth. However, as will be described later, if an error occurs, some recovery is necessary because the retransmission procedure does not exist in the protocol (there is no recovery processing in the processing E).

Next, processing F for performing image data transfer using asynchronous transfer will be described with reference to FIG.

In step S720, processing for transmitting the prescanned image data in the asynchronous transfer mode is started. Then, in step S721, the image data is transmitted to the host computer 214 for each packet in the asynchronous transfer mode.

In step S722, it is determined whether the transmitted packet has not been correctly received due to a problem on the line or the state of the receiving node, that is, whether an error has occurred. If an error has occurred, the process proceeds to step S723; otherwise (if the transfer is successful), the process proceeds to step S724.

In step S723, in response to the occurrence of the error, a retransmission procedure is performed in accordance with the IEEE1394 protocol, and the flow returns to step S722. This processing enables all packets to be transmitted without data loss.

In step S724, it is determined whether all the image data has been transmitted. When all packets have been processed, the processing sequence of the processing F ends.
If not, that is, if packets to be transmitted still remain, the process returns to step S721 to continue the transmission process.

The feature of the process F is that an asynchronous transfer mode having a retransmission procedure is used for the transfer of a prescan image, whereby information such as color information in which data drop is not allowed can be reliably transferred. However, the asynchronous transfer has disadvantages such as a lower priority of acquiring a band as compared with the isochronous transfer and a longer time since processing in the transaction layer unit is performed for each packet.

Next, processing G for performing image data transfer using isochronous transfer will be described with reference to FIG.

In step S725, the transmission packet size described in step S715 is set, and the set transmission data information is transmitted to the host computer 214 using asynchronous transfer in which retransmission is performed when an error occurs. Although not shown in the figure, it is also set whether to divide each color into packets. A method of transmitting a packet of a certain size for each color and a method of transmitting data of a packet size for each color can be selected.

In step S726, processing for transmitting the prescanned image data in the isochronous transfer mode is started. Then, in step S727, the image data is transmitted to the host computer 214 for each packet by isochronous transfer.

In step S728, it is determined whether the transmitted packet has not been correctly received due to a problem on the line or the state of the receiving node, that is, whether an error has occurred. Since there is no retransmission procedure at the time of isochronous transfer on the protocol of IEEE1394, it becomes an original protocol. In this embodiment, serial number data is added to a packet at the time of isochronous transfer. If the host computer 214 determines that an error has occurred or that a packet has been lost, the host computer 214 notifies the image reading apparatus 201, which is the transmitting side of the packet, of the number of the lost packet (a serial number defined by a unique protocol). Then, retransmission processing is performed in response to this. If an error has occurred, the process proceeds to step S729; otherwise (if the transfer is successful), the process proceeds to step S730.

In step S729, in response to the occurrence of the error, a retransmission procedure is performed using the asynchronous transfer protocol. This processing enables all packets to be transmitted without data loss. At this time, if the transfer of the packet is performed for each color, and it is notified that the color image data is not necessary in the future at the time of the retransmission request from the host computer 214, the subsequent data transfer will be monochrome image data (only luminance data).

In step S730, it is determined whether all the image data has been transmitted. When all the packets have been processed, the processing sequence of the processing G ends.
If not, that is, if there is still a packet to be transmitted, the process returns to step S727 to continue the transmission process.

The feature of the process G is that the prescan image is transferred using an isochronous transfer mode without a retransmission procedure, and when an error occurs, an asynchronous transfer with a retransmission procedure is used. is there. High-speed transfer without data loss becomes possible. However, since a retransmission procedure is performed when an error occurs, the time required for the transfer may be longer than that in the processing E.

Although not described in the other drawings, there is a method of transmitting the same image data using both transfer modes of the isochronous transfer and the asynchronous transfer. When the host computer 214 determines that the packet at the time of error occurrence is missing, it does not issue a request for retransmission to the image reading apparatus main body 201, but acquires the image data transmitted by asynchronous transfer. However, there is a possibility that the asynchronous transfer with lower bus priority compared to the isochronous transfer may be delayed even if the same packet is transmitted. Therefore, basically, the packet transmitted isochronously was received and an error occurred. When it is determined that the packet is transmitted later by the asynchronous transfer, the packet is applied to the portion that seems to be missing. Other packets transmitted by asynchronous transfer are discarded after reception. This method occupies a band more than necessary because the same data is transmitted twice from the same device, but is a processing method having both transfer speed and reliability.

FIG. 15 is a flowchart showing the procedure of the storage process according to the first embodiment.

In step S801, it is determined whether to store image data in the memory 204. If the storage is to be performed, the process proceeds to step S802; otherwise, the storage process ends.

In step S802, it is determined whether to compress the image data. If compression is performed, the process advances to step S803 to compress the read image data. The compression in the embodiment employs reversible compression. On the other hand, if compression is not to be performed, otherwise the process of step S803 is skipped and the process proceeds to step S804.

In step S804, the image data is stored in the memory 2
Store in 04.

In step S805, it is determined whether or not all the image data has been stored in the memory 204. If all are stored, the process ends. If not, the process returns to step S804 to perform the process of storing in the memory 204.

As a result, the memory 204 for reading an enormous amount of image data can be effectively used. Also,
Even when there is a request for retransmission from the host computer 214 side, image data can be transmitted without rereading an image, that is, processing time can be reduced. Note that whether or not to store and whether or not to compress is in accordance with a command from the host computer.

FIG. 16 is a flowchart showing the procedure of the correction data creation processing according to the first embodiment.

In step S901, it is determined whether correction data to be used for the main scan or for use in the prescan is to be generated. Here, when the correction data is created, four correction data creation processes are performed in step S
Proceed from 902 to 905, respectively. If not, the process ends.

In step S902, it is determined whether the size or position of the document is to be detected. If the size / position is to be detected here, the process proceeds to step S906; otherwise, the process proceeds to step S913. In step S906, the size of the original is determined by detecting the leading end position and the end of the original. Detect the position. In step S907, data for correcting the scanning position is created based on the size / position detection data detected in step S906.

When the process proceeds to step S903, it is determined whether or not the dynamic range of the input signal is detected. If the dynamic range is detected here, the process proceeds to step S908; otherwise, the process proceeds to step S913. In step S908, the dynamic range of the input signal is detected by detecting the maximum value and the minimum value of the input signal. In step S909, input level correction data is created based on the dynamic range detection data detected in step S908.

When the processing has proceeded to step S904,
It is determined whether or not to detect color information, for example, information such as a background color level and a color balance of each RGB color. If detection is selected here, the process proceeds to step S910. Otherwise, the process proceeds to step S913. In step S910, color information is detected. In step S911, color correction data is created based on the color information detected in step S910.

In step S905, it is determined whether or not the attribute of an object in the document, for example, text, graphic, image or the like is determined. If the user selects to make a determination here, the process proceeds to step S912; otherwise, the process proceeds to step S911. In step S912, an object for each block in the document is determined. Step S
In 913, when the correction data is created, the data is stored in the memory 204.

Whether or not the correction data is to be created depends on the instruction command from the host computer, of course, which correction data should be created.

In this flowchart, it is assumed that the respective correction data creation processes are performed in parallel. This is because a hardware configuration is considered in the configuration described this time, and when this is performed by software, sequential processing is performed.

FIG. 17 is a flowchart showing a control procedure of the main scan according to the first embodiment.

In step S1001, the moving speed (resolution in the sub-scanning direction) of the scanner is set based on the setting from the user (host computer). Since this image reading device is assumed to be a line sensor, the scanner device 20
5 controls the moving speed in the sub-scanning direction via the drive unit 301 so that a desired resolution can be obtained.

In step S1002, when there is correction data for the main scan, it is determined whether to correct the image data using this value. When the correction data is used, correction is set in step S1003. Thus, the reading position and the input level of the document are set. In addition, if necessary, the color and density are set to be corrected.
If data correction is not performed, the process of step S1003 is skipped.

In step S1004, a signal is transmitted to the drive unit 301 to start the movement of the scanner. Then, step S10
At 05, the image is read and the operation is performed. Further, the image data read in parallel with this is transmitted to the host computer 214 (the processing after step S1009) or stored in a storage medium in the image reading apparatus 201 (step S100
Perform 8). However, these processes may be performed serially, or may be performed in parallel depending on the configuration.

In step S1006, it is determined whether reading of the image has been completed. If the reading has been completed, the process proceeds to step S1007.
It returns to 1005 and continues reading processing.

In step S1007, when scanning of the end of the document or the trimming designated area is completed, the scanner is stopped. As described above, the driving of the scanner is processed in parallel with the transmission to the host and the storage in the memory.

In step S1008, a storage process for storing the read image data is performed. The details have been described with reference to FIG.

On the other hand, in step S1009 executed in parallel with the image reading process, it is determined whether image data can be transmitted to the host computer 214. If communication with the host computer 214 is possible, step S1
Go to 011. Otherwise, proceed to step S1010,
The user is notified via the user interface 210 of the image reading device 201 that image data cannot be transmitted to the host computer 214.

When the processing has proceeded to step S1011,
It is determined whether to compress the image data to be transferred. If compression processing is to be performed, the flow advances to step S1012 to compress the read image data. If compression is not performed, the process of step S1012 is skipped.

In step S1013, it is determined whether to use the isochronous transfer mode for transferring image data. If the isochronous transfer mode is used, the process proceeds to step S1015. If not, that is, if the asynchronous transfer mode is used, the process proceeds to step S1014.

In step S1014, processing F for performing image data transfer using asynchronous transfer is performed. The details of the processing have already been described with reference to FIG.

In step S1015, processing G for performing image data transfer using isochronous transfer is performed. The details of the processing have already been described with reference to FIG.

The above is the processing on the image reading apparatus side, but the processing of the operation processing (mainly the driver program of the image scanner) on the receiving side, that is, the host computer side will be described below.

FIG. 1 is a flowchart showing a control procedure on the receiving side according to the first embodiment.

First, in step S101, a reading requirement is set. Specifically, it instructs the image reading device 201 to perform a document reading operation, and determines whether the image reading operation is a pre-scan or a main scan, the resolution, and whether color information is required. And various settings such as what to do with the transfer mode. These setting items are set, for example, through a user interface displayed on a display screen of the host computer.

In step S102, the requirements set in step S101 are transmitted to the image reading device 201 by asynchronous transfer. The reason for using the asynchronous transfer is to ensure that the request is correctly transferred to the image reading apparatus. That is, when the transmitted requirements cannot be correctly received by the image reading apparatus, retransmission processing is performed in accordance with the IEEE1394 protocol to perform reliable transfer.

In the step S103, it is determined whether or not the reading operation requested here is a pre-scan. In the case of the pre-scan, the process proceeds to step S104, and in the case of the main scan, the process proceeds to step S113.

In step S104, it is determined whether or not color information is necessary at the time of prescan. If color information is required, the process proceeds to step S105, and if not, the process proceeds to step S108.

In step S105, if color information is required, it is determined whether or not to use the isochronous transfer mode for transferring the image data. If the isochronous transfer mode is used, the process proceeds to step S107. If not, that is, if the asynchronous transfer mode is used, the process proceeds to step S106.

In step S106, image data transfer processing A using asynchronous transfer is performed (the processing contents will be described later with reference to FIG. 2). In step S107, image data transfer processing B using isochronous transfer is performed. (The processing contents will be described later with reference to FIG. 3).

In step S108, the image reading device 201
Receives the transmission data information (described above) transferred in the asynchronous transfer mode. When an error occurs on the line or at the time of reception, a request for retransmission is issued and information is reliably obtained.

In step S109, image data transfer processing C using isochronous transfer is performed (the processing contents will be described later with reference to FIG. 4).

In step S110, it is determined whether or not to use the isochronous transfer mode for transferring the image data of the main scan. If the isochronous transfer mode is used, the process proceeds to step S112. If not, that is, if the asynchronous transfer mode is used, the process proceeds to step S112.
Proceeding to 111, the same processing A as in step S106 is performed.

In step S112, image data transfer processing D using isochronous transfer is performed (the contents of the processing will be described later with reference to FIG. 5).

When any of the receiving processes is performed, the process proceeds to step S113, and it is determined whether the data in the received packet is compressed. If compressed, the process proceeds to step S113; otherwise, the process proceeds to steps S116 and S117.

In step S114, if the data is compressed, it is determined whether or not the data should be expanded. If the decompression process is to be performed, the process proceeds to step S115; otherwise, the process proceeds to step S116. In step S115, decompression processing of the compressed image data is performed. In step S116, storage processing of the received image data is performed.

In this flowchart, the processing is performed after all the image data has been received. However, the storage operation is actually performed every time a packet is received. Although not shown in the drawing, if the compressed image data is stored and stored without being decompressed, it is necessary to perform the decompression process in step S115 when displaying the image data.

In step S117, a process of displaying the received image data on display unit 220 is performed. This can give the user information and judgment information such as whether the read image is desired, whether the read position is correct, and whether the color and density are correct.

In the step S118, it is determined whether or not there is a request to read the image again. If there is a re-request, the process is repeated from step S101. If there is no image reading request, all the processes related to image reading are ended.

Next, image data reception processing A using asynchronous transfer will be described with reference to FIG.

In step S119, processing for receiving the image data of the pre-scan and the main scan in the asynchronous transfer mode is started.

In the step S120, the image reading device 201
It is determined whether or not the packet transmitted from is correctly received depending on the problem on the line or the state of the receiving node, in other words, whether or not an error has occurred. If an error has occurred, the process proceeds to step S121, and a request for retransmission in the asynchronous transfer mode is made to the image reading apparatus 201 in accordance with the IEEE1394 protocol. This processing enables all packets to be transmitted without data loss. The process of receiving the retransmitted packet returns to step S119 and is performed.

If the image data has been received normally, the flow advances to step S122 to determine whether all the image data have been received. When all the packets have been processed, the sequence of the process A ends. Otherwise, that is, if there is still a packet to be transmitted, the process returns to step S119 to continue the reception process.

Next, transfer processing B of prescanned image data using isochronous transfer will be described with reference to FIG.

In step S123, the image reading device 201
The above-mentioned transmission data information is received by asynchronous transfer in which retransmission is performed when an error occurs. As a result, information such as the size of the transmitted image data, the packet size, and the total number of packets is obtained.

In step S124, processing for receiving prescanned image data in the isochronous transfer mode is started. Image data is received from the image reading device 201 for each packet by isochronous transfer.

In step S125, the image reading device 201
It is determined whether or not the packet transmitted from has not been correctly received due to a problem on the line or the state of the receiving node, and whether or not an error has occurred. Since there is no retransmission procedure at the time of isochronous transfer according to the IEEE1394 protocol, the subsequent processing is an original protocol. If the host computer 214 determines that an error has occurred or that a packet has been lost, the process proceeds to step S126. Otherwise, the process proceeds to step S136.

Whether an error has occurred is determined by the size of image data obtained in advance, the size of one packet, the total number of packets, and the number of the packet added to the packet (specified by a unique protocol). serial number)
By determining packet loss or grasping and setting the interval at which packets are transferred from the band that can be transferred in the isochronous transfer mode acquired after the IEEE1394 bus configuration. The cycle start packet is used to determine the packet transfer interval.

In step S126, the location where the error has occurred is specified in response to the occurrence of the error. Specifically, the display location of the image data is specified from a serial number or a transfer cycle defined by a unique protocol.

In step S127, if the packet transmission is performed for each color, it is determined whether or not the color information of the missing packet is supplemented with another color. Specifically, use other color data as missing color data as it is,
A method of using the data of the color received before the lost packet may be used. In these methods, it is inevitable that the color of only that portion changes, but only the position information can be stored and displayed. When supplementing with another color, the process proceeds to step S128; otherwise, the process proceeds to step S130.

When the processing has proceeded to step S128,
Understand missing colors. Since three colors of R, G, and B are alternately transmitted as colors, the color that would have been possessed by the packet that was lost from the previously transmitted colors is determined. Specifically, the data of the color component that would have been lost is the data of the same color component that was received last. In step S129, a color other than the missing color is selected, and the missing color data is interpolated with the selected color data.

In step S130, it is determined whether or not to convert a color image into a monochrome image, based on the fact that color information is not necessary at the time of prescanning in the middle of an error. If conversion to a monochrome image is to be performed, the process proceeds to step S131.

In step S131, a specific color for conversion to a monochrome image is set. Specifically, a G component is used as a luminance component. If the color information of the missing packet is G, a retransmission request is made by asynchronous transfer. At this time, it informs that image data to be transferred thereafter is only luminance data. If the missing color is a color other than G, only the request for the subsequent data transfer to monochrome image data is made.

In step S132, if a retransmission request has been issued in step S131, the packet is received. Further, it converts the color image data already received and stored or displayed on the display unit 220 into monochrome image data.

In step S133, in response to the occurrence of the error, a request for retransmission in the asynchronous transfer mode is made to the image reading apparatus 201 in accordance with the IEEE1394 protocol. This processing enables all packets to be transmitted without data loss.

In step S134, an asynchronous packet is received. The data of the received packet is inserted into the position of the data considered to be missing.

In step S135, the image reading device 201
It is determined whether the retransmitted packet transmitted asynchronously transmitted from is not correctly received due to a problem on the line or the state of the receiving node, and whether an error has occurred. If the host computer 214 determines that an error has occurred or that a packet has been dropped, the process proceeds to step S133. If it is not determined that an error has occurred, the process proceeds to step S136.

In the step S136, it is determined whether or not all the image data has been received. When all packets have been processed, the sequence of the process B ends. If not, that is, if there is still a packet to be received, the process returns to step S124 to continue the receiving process.

Next, transfer processing C of prescan image data not including color information using isochronous transfer will be described with reference to FIG.

First, in step S137, processing for receiving prescanned image data in the isochronous transfer mode is started.

In step S138, the image reading device 201
It is determined whether the packet transmitted from the terminal has been correctly received due to a problem on the line or the state of the receiving node, and whether an error has occurred. If an error has occurred, the process proceeds to step S139; otherwise (if the transfer is successful), the process proceeds to step S142.

In step S139, in response to the occurrence of the error, the size of the packet to be received and the position where the data of the packet should be displayed are specified. Then, in step S140, dummy data (data having a value of 0) for the packet size specified in step S139 is created.
If the received image data is used only for display, data is created in a size required for display. In step S141, the data created in step S140 is handled as received image data. When the data is stored in the RAM 217, the storage process is continued, and when the data is displayed on the display unit 202, the display process is continued.

In the step S142, it is determined whether or not all the image data has been received. The process from step S137 is repeated until it is determined that all packets have been processed. If it is determined that all the data has been received, the sequence of the process C ends.

In the processing C, the processing time is reduced by not performing any retransmission procedure. In addition, the adverse effect of not performing retransmission processing (eg, displacement of position information due to lack of image data) is improved by creating dummy data on the receiving side.

Next, transfer processing D of main scan image data using isochronous transfer will be described with reference to FIG.

First, in step S143, the above-described transmission data information from the image reading apparatus 201 is received by asynchronous transfer for retransmission when an error occurs. The size of the image data transmitted by this,
Obtain information such as packet size and total number of packets.

Next, in step S144, processing for receiving the main scan image data in the isochronous transfer mode is started. Image data is received from the image reading device 201 for each packet by isochronous transfer. In step S145, it is determined whether the packet transmitted from the image reading apparatus 201 could not be correctly received due to a problem on the line or the state of the receiving node, and whether an error has occurred. According to the IEEE 1394 protocol, there is no retransmission procedure at the time of isochronous transfer, so that the subsequent processing is an original protocol as described in step S125. If the host computer 214 determines that an error has occurred, that is, that the packet has been lost, the process proceeds to step S146. If it is not determined that an error has occurred, the process proceeds to step S150. The description of the determination as to whether or not an error has occurred has been described in step S125, and will not be described.

In step S146, the location where the error has occurred is specified in response to the occurrence of the error. Specifically, the display location of the image data is specified from a serial number or a transfer cycle defined by a unique protocol.

In step S147, in response to the occurrence of the error, a request for retransmission in the asynchronous transfer mode is made to the image reading apparatus 201 in accordance with the IEEE1394 protocol. This processing enables all packets to be transmitted without data loss.

At step S148, an asynchronous packet is received. The data of the received packet is inserted into the position of the data considered to be missing.

In the step S149, the image reading device 201
It is determined whether the retransmitted packet transmitted asynchronously transmitted from is not correctly received due to a problem on the line or the state of the receiving node, and whether an error has occurred. If the host computer 214 determines that an error has occurred or that a packet has been dropped, the process proceeds to step S147. If it is not determined that an error has occurred, the process proceeds to step S150.

In step S150, it is determined whether all the image data has been received. When all the packets have been processed, the sequence of the process C ends. If not, that is, if there are still packets to be received, the process returns to step S144 to continue the reception process.

In the present embodiment, regarding the transmission of image data using isochronous transfer and the handling when an error occurs,
The processing is selected depending on whether color information is required or not, but this is merely an example. Even when color information is needed, the retransmission procedure processing for error correction may be omitted depending on the user's judgment (selection or setting), and processing may be selected for items other than color information. In other words, transmission of packets by normal isochronous transfer, transmission processing of performing some retransmission procedure not specified by the IEEE1394 interface protocol when an error occurs while using isochronous transfer, and packet transmission by asynchronous transfer are selected by the user's judgment It is possible to This judgment (selection) by the user may be set every time the image is read, or the process may be skipped if it is registered once as a specified value.

FIG. 18 is a schematic diagram showing a state in which image data is lost due to occurrence of an error in the first embodiment.

FIGS. 27A and 27C are schematic diagrams of image data read by prescanning. The image data is divided so as to fit in the size of the transmission packet and transferred to the receiving side. (a) shows a case where the band is divided in the sub-scanning direction, and (c) shows a case where the band is divided into blocks in both the main scanning and the sub-scanning. The number shown in (a) (1
12) are for convenience of identifying the divided bands, and the numbers and alphabets shown in (c) are for convenience of identifying the blocks. If the band (5) or the block (3b) indicated by a dot in each figure is a packet that could not be received due to an error during isochronous transfer, a recovery procedure such as retransmission must be performed. Even if there is no data, the data of the missing packet size is supplemented on the receiving side, so that the display of the prescanned image data on the receiving side is as shown in FIGS. That is, in either case, the band or the block is missing, so that the portion cannot be displayed, but the image is not shifted due to the missing. For example, in the case of FIG. 3B, there is no shift due to the data having a value of 0 entering where band 5 should originally come. Although the total number of packets to be received is reduced by one, the number of displayed packets is the same. Also, in the case of FIG.
The place where is displayed is blank but does not shift. Here also, the total number of received packets is reduced by one, but the displayed size is the same as the size of the transmitted image. As described above, by compensating for the packet loss by the size, it is possible to grasp the position information of the image originally intended in the pre-scan without performing the retransmission procedure or the reading operation again.

FIG. 19 shows an example of the IEEE1394 bandwidth when transmitting prescan data by isochronous and asynchronous transfer according to the first embodiment.

Numerals 1201 to 1204 are cycles that occur repeatedly. IEEE1394 interface cycle is 125 μs
ec. 1205 is a cycle start packet indicating the start of a frame. 1206, 1207 and 1208 are the bandwidths used in the isochronous transfer. Where 12
What is transmitted using the band 06 is prescanned image data that does not require color information (even if there is some data omission, the purpose of obtaining position information and the like can be realized). 1207 is a digital video camera
This is a band for transferring the video data. Reference numeral 1208 denotes a band for transferring moving image data from a CCD camera, which is required when a TV conference system or the like is built on a PC. 1209 and
Reference numeral 1210 denotes a bandwidth used in asynchronous transfer. Here, pre-scanned image data having color information (having information in which data drop is not allowed) is transmitted using the band 1209. In this band, retransmission is performed when an error occurs. Reference numeral 1210 denotes a band for transferring print data of the printer. 1211 is an unused bandwidth.

With the above configuration and processing, the original purpose of the pre-scan such as confirmation of the read image and designation of the area at the time of the main scan (designation of the trimming range) is satisfied, and the time required for transmitting the pre-scan image data is reduced. be able to. In particular, when the user aims to grasp the position and size of the original document, specify the entire read image, and specify the trimming range, the above-mentioned object can be achieved without performing a retransmission procedure even if a packet is lost due to an error during packet transfer. be able to.

<Second Embodiment> A second embodiment of the present invention will be described with reference to the drawings.

In the second embodiment, the interface for configuring the system is IEEE1394 in the first embodiment, but is replaced by USB in this embodiment. Therefore, the configuration is the same as that of the first embodiment except for a block diagram showing the configuration of the system and details thereof, and the description of the remaining same parts is omitted.

FIG. 20 is a block diagram showing the configuration of the image reading system according to the first embodiment.

In the figure, reference numeral 1301 denotes an image reading apparatus main body.
It is composed of blocks 1302-1308 described below, and mainly has a scanner function for reading a document, an image processing function, and a communication function for transmitting image data.

Reference numeral 1302 denotes a CP for executing a program for controlling the entire image reading apparatus 1301 and various image processing.
U. A ROM 1303 stores programs executed by the CPU 1302 and various control information. The control information can be updated later by using a flash memory or the like. A RAM 1304 stores data and programs used by the CPU 1302, various image data read by the scanner 1305, and created correction data. Reference numeral 1305 denotes a scanner for reading a document, which includes a light source for reading the document, a CCD sensor, an A / D converter, an image signal correction circuit, and the like. Details have already been described with reference to FIG.

[0194] Reference numeral 1306 denotes an image reading device 1301 to the user.
This is a user interface for notifying the status of the main unit and communication, and accepting command input from the user. It comprises a display unit for notification and an operation unit for receiving input. A USB device control unit 1307 controls USB communication. Details will be described later with reference to FIG. 1308 is a system bus. In addition to the constituent blocks 1302 to 1307 of the illustrated image reading apparatus 1301, constituent elements (not shown) are also connected to this bus, and high-speed data transfer can be performed between the blocks.

Reference numeral 1309 denotes a USB interface cable. In this cable, there are four cables including two signal lines and two power supply pair cables.

Reference numeral 1310 denotes a host computer. USB requires a host computer for system configuration. In this system configuration, a reading request is made to an image reading device (scanner device) 1301 and image data transferred from the image reading device (scanner device) 1301 is received.

[0197] Reference numeral 1311 denotes a USB device control unit for controlling USB communication, and has the same function as the above-mentioned 1307. Reference numeral 1312 denotes a CPU which executes an application program which is one of the components of the system for controlling the host computer body 1310 and reading the scanner. Other USB interface drivers are also executed.

A RAM 1313 temporarily stores data and programs used in the CPU 1312 and various image data transmitted from the scanner device 1301. 131
Reference numeral 4 denotes a hard disk drive for storing programs executed by the CPU 1312, control information, and various image data. Reference numeral 1315 denotes a system bus, and devices (not shown) are also connected to the system bus. 1316
Is a CRT or LC connected to the host computer 1310
And a display unit made of D or the like. The display of the transmitted image data and the setting at the time of reading are displayed.

Reference numeral 1317 denotes an operation unit including a keyboard, a mouse, and the like connected to the host computer 1310. Thus, operations on the application such as various reading settings are performed.

The difference from the first embodiment is that, as described above, the interface is replaced by IEEE1394 to USB, and that the creation of correction data and various image processing are performed by dedicated hardware logic (ASIC). There are cases where software processing has changed from use.

FIG. 21 is a block diagram of the USB interface according to the second embodiment. In the figure, reference numeral 1401 denotes a system interface logic unit which performs an interface with a scanner system, especially a CPU. Here, it is responsible for an interface between the SIE and the CPU, which will be described later. 14
02 is an SIE (Serial Interface Engine). U
Responsible for basic operation of SB. 1403 is a FIFO,
It is connected to the system interface 1403 and serves as a transmission / reception buffer for a USB endpoint.

FIG. 22 shows an example of the USB bandwidth when transmitting prescan data by isochronous and bulk transfer according to the second embodiment.

Reference numerals 1501 to 1504 denote frames which repeatedly occur. 1505 is the SOF (Start
Of Frame) packet. 1506 and 1507 are the bandwidths of the isochronous transfer. Here, what is transmitted using the band 1506 is prescanned image data without color information (for the purpose of being allowed even if there is some data omission). 1508 is the bandwidth of the interrupt transfer. Here, a keyboard is used as an example. 1509 is the bandwidth of the bulk transfer. Here, pre-scanned image data having color information is transmitted using the band 1509. In this band, retransmission at the time of error is performed. 1510 is
Unused bandwidth.

In this example, two pre-scan image data (image data for isochronous transfer having no color information and image data for bulk transfer having color information) are simultaneously transmitted in different bands, but one of each is transmitted. However, it can also be transmitted, and can also be transmitted when necessary according to a request from a user after being stored in the memory.

With the above configuration, it is possible to satisfy the original purpose of the pre-scan such as confirmation of a read image and designation of an area (designation of a trimming range) at the time of the main scan, and to shorten the time required for transmitting the pre-scan image data. it can. Since the USB interface has a lower transfer speed than the IEEE1394 interface, it is effective for effective use of the bus and efficient transmission of image data.

An object of the present invention is to supply a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU or MPU) of the system or apparatus.
Needless to say, this can also be achieved by the PU) reading and executing the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS and the like running on the computer are actually executed based on the instructions of the program code. It goes without saying that a part or all of the above-described processing is performed, and the functions of the embodiments are realized by the processing.

Further, after the program code read from the storage medium is written into the memory provided in the extension function board inserted into the computer or the function extension unit connected to the computer, based on the instruction of the program code, It goes without saying that the CPU provided in the function expansion board or the function expansion unit performs a part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

Further, in the embodiment, the example in which the image reading apparatus and the host computer are connected has been described. However, the image data generating source is not limited to the image reading apparatus such as the image scanner. For example, the image data may be stored in a predetermined storage medium in advance and transferred to the host computer. An example of this is a digital camera.

As described above, according to the present embodiment,
The following effects can be obtained. -The original purpose of the pre-scan such as confirmation of the read image and designation of the area for the main scan (designation of the trimming range) is satisfied, and the time required for transmitting the pre-scan image data can be reduced. -Even if an error occurs during transfer of prescanned image data and data is lost, a desired prescanned image can be displayed on the receiving side without performing a retransmission procedure.・ Even if isochronous transfer is used when transferring image data that does not allow data loss such as color information or main scan, it is ensured by using a transfer mode with a retransmission procedure together when an error occurs during data packet transmission. And high-speed data transfer can be realized. Whether the size of the packet to be transferred is determined so that a constant multiple of the data length in the main scanning direction when displaying the pre-scan image on the receiving node matches the data length of the packet,
By determining that a predetermined number of times the data length of the packet matches the data length of the prescan image to be displayed in the main scanning direction, display of prescan image data on the receiving side and interpolation processing when data is lost Thus, the total processing time can be reduced by reducing the load on the system.

[0213]

As described above, according to the present invention, first, when confirming the contents of an image from, for example, an image scanner or an image data source, a high-speed transfer is performed. Even if an error occurs, it is possible to eliminate the influence on the layout of the entire image.

Second, an image read by an image scanner or the like or image data of an image data source is transferred at a high speed, and even if an error occurs during the transfer, the error occurs. By transferring only data in a transfer mode having a retransmission procedure, both high-speed transfer and image quality can be guaranteed.

[0215]

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a control procedure on a receiving side according to a first embodiment.

FIG. 2 is a flowchart showing the contents of a process A in FIG. 1;

FIG. 3 is a flowchart showing the contents of a process B in FIG. 1;

FIG. 4 is a flowchart showing the contents of a process C in FIG. 1;

FIG. 5 is a flowchart showing the contents of a process D in FIG. 1;

FIG. 6 is a block diagram of the image reading system according to the first embodiment;

FIG. 7 is a block configuration diagram of a scanner unit according to the first embodiment.

FIG. 8 is a block diagram of an IEEE1394 interface control unit according to the first embodiment.

FIG. 9 is a flowchart illustrating a control procedure on the image data transmitting side according to the first embodiment.

FIG. 10 is a flowchart illustrating a pre-scanning procedure according to the first embodiment.

FIG. 11 is a flowchart illustrating a procedure of a transmission process according to the first embodiment.

FIG. 12 is a flowchart showing the contents of a process E in FIG. 11;

FIG. 13 is a flowchart showing the contents of a process F in FIG. 11;

FIG. 14 is a flowchart showing the contents of processing G in FIG. 11;

FIG. 15 is a flowchart illustrating a procedure of a storage process according to the first embodiment.

FIG. 16 is a flowchart illustrating a procedure of a correction data creation process according to the first embodiment.

FIG. 17 is a flowchart illustrating a control procedure of a main scan according to the first embodiment.

FIG. 18 is a diagram illustrating a display example when image data is lost due to occurrence of an error in the first embodiment.

FIG. 19 is a diagram showing an IEEE1394 bandwidth of the first embodiment.

FIG. 20 is a block diagram of an image reading system according to a second embodiment.

FIG. 21 is a block diagram illustrating a configuration of a USB interface control unit according to the second embodiment.

FIG. 22 is a diagram illustrating a USB bandwidth according to the second embodiment.

FIG. 23 is a diagram illustrating an example of a USB connection configuration.

FIG. 24 is a diagram illustrating an example of a USB bandwidth.

FIG. 25 is a diagram illustrating an example of a display defect when image data is lost due to occurrence of an error.

Claims (42)

[Claims] 1. An image reading apparatus comprising: an image reading device and an information processing device connected via a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs. A processing system, wherein the information processing apparatus determines whether an error has occurred in receiving a data packet from the image reading apparatus using the first transfer mode at the time of pre-scanning a document image; and If the determination means determines that an error has occurred,
A dummy data creating means for creating dummy data of a data size of the error packet without making a retransmission request of the data packet in which the error occurred, and generating an image based on the normally received data and the dummy data. An image processing system characterized by being constructed. 2. The communication interface according to claim 1, wherein said communication interface is IEEE13.
2. A first interface according to claim 1, wherein
The image processing system according to the item. 3. The image processing system according to claim 2, wherein said first transfer mode is an isochronous transfer mode, and said second transfer mode is an asynchronous transfer mode. 4. The communication interface is Universalsail.
2. The image processing system according to claim 1, wherein the image processing system is a serial bus interface. 5. The apparatus according to claim 1, wherein the dummy data creating means creates dummy data having a data content of “0” when the data to be received does not include color information. Image processing system. 6. The image processing system according to claim 1, wherein the determination unit determines that a packet is lost due to an error or the like based on the transmission data information. 7. The image processing system according to claim 6, wherein the transmission data information is transmitted before transfer of the image data. 8. The transmission data information according to claim 6, wherein the transmission data information is a total number of the data packets.
The image processing system according to the item. 9. The image processing system according to claim 6, wherein the transmission data information is a transmission packet size. 10. The transmission data information according to claim 6, wherein the transmission data information is packet transmission interval information.
The image processing system according to the item. 11. The image processing system according to claim 10, wherein the transmission interval information is a time stamp. 12. The image processing system according to claim 10, wherein the transmission interval information is a cycle start packet. 13. When the pre-scan image data includes color information, the dummy data generating means generates the dummy data based on image information of a color other than the missing color. Item 2. The image processing system according to Item 1. 14. The method according to claim 1, wherein the dummy data generating means converts the color image into a monochrome image using luminance information when the prescan image data includes color information. The image processing system according to the item. 15. A size determining means for determining a packet size such that a predetermined multiple of a data length in a main scanning direction of a prescan image to be displayed matches a data length of a packet to be transmitted. The image processing system according to claim 1, wherein: 16. The apparatus according to claim 1, further comprising a size determining means for determining a packet size such that a predetermined number of times the data length of the packet to be transmitted matches the data length of the prescan image to be displayed in the main scanning direction. The image processing system according to claim 1, wherein: 17. An image reading apparatus having a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs.
An information processing apparatus for receiving image data via the communication interface, wherein an error has occurred in receiving a data packet from the image reading apparatus using the first transfer mode during pre-scanning of a document image. Determining means for determining whether an error has occurred; and
Dummy data creation means for creating dummy data of the data size of the error packet without making a retransmission request of the data packet in which the error occurred,
An information processing apparatus for constructing an image based on normally received data and dummy data. 18. An image reading apparatus having a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs.
A method of controlling an information processing apparatus for receiving image data via the communication interface, wherein an error occurs in receiving a data packet from the image reading apparatus using the first transfer mode during pre-scanning of a document image. A determining step of determining whether or not an error has occurred in the determining step;
A dummy data creating step of creating dummy data for the data size of the error packet without making a retransmission request for the errored data packet,
A method for controlling an information processing apparatus, comprising: constructing an image based on normally received data and dummy data. 19. An image reading apparatus having a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs.
A storage medium storing a program code functioning as an information processing device for receiving image data via the communication interface, wherein data from the image reading device is used by using the first transfer mode during pre-scanning of a document image. A program code for a determination step of determining whether an error has occurred in packet reception; and determining that an error has occurred in the determination step,
A storage medium comprising: a program code for a dummy data creation step of creating dummy data of a data size of the error packet without requesting a retransmission of the errored data packet. 20. An image data generating source and an information processing device connected via a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs. An image processing system, wherein the information processing apparatus determines whether an error has occurred in receiving a data packet from the image data source using the first transfer mode, Determines that an error has occurred,
A dummy data creating means for creating dummy data of a data size of the error packet without making a retransmission request of the data packet in which the error occurred, and generating an image based on the normally received data and the dummy data. An image processing system characterized by being constructed. 21. Image data is received from an image data source having a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs, via the communication interface. A determination unit that determines whether an error has occurred in receiving a data packet from the image data generation source using the first transfer mode; and an error has occurred by the determination unit. Is determined,
Dummy data creation means for creating dummy data of the data size of the error packet without making a retransmission request of the data packet in which the error occurred,
An information processing apparatus for constructing an image based on normally received data and dummy data. 22. An image constituted by an image reading device and an information processing device connected via a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs. A processing system, wherein the information processing apparatus determines whether an error has occurred in receiving a data packet from the image reading apparatus using the first transfer mode during pre-scanning and main scanning of a document image. Determining means; determining that an error has occurred by the determining means;
An image processing system comprising: a retransmission request unit that requests retransmission of the data packet in which the error has occurred in the second transmission mode. 23. The communication interface according to claim 1, wherein:
The image processing system according to claim 22, wherein the image processing system is a 394 interface. 24. The transfer method according to claim 23, wherein the first transfer mode is an isochronous transfer mode, and the second transfer mode is an asynchronous transfer mode.
The image processing system according to the item. 25. The communication interface according to claim 1, wherein the communication interface is a universal.
23. The image processing system according to claim 22, wherein the image processing system is a Serial Bus interface. 26. The image processing system according to claim 22, wherein said information processing apparatus further comprises display means for displaying an image based on the received data. 27. The image processing system according to claim 22, wherein said determination means determines that a packet is lost due to an error or the like based on transmission data information. 28. The image processing system according to claim 27, wherein said transmission data information is transmitted before image data is transferred. 29. The image processing system according to claim 27, wherein said transmission data information is a total number of said data packets. 30. The transmission data information according to claim 27, wherein the transmission data information is a transmission packet size.
The image processing system according to the item. 31. The image processing system according to claim 27, wherein said transmission data information is packet transmission interval information. 32. The image processing system according to claim 31, wherein said transmission interval information is a time stamp. 33. The image processing system according to claim 31, wherein the transmission interval information is a cycle start packet. 34. The image processing apparatus according to claim 34, wherein when the pre-scan image data includes color information, the dummy data generating means generates the dummy data based on image information of a color other than the missing color. Item 23. The image processing system according to Item 22. 35. The image processing apparatus according to claim 22, wherein the dummy data generating means converts a color image into a monochrome image using luminance information when the prescan image data includes color information. The image processing system according to the item. 36. A size determining means for determining a packet size such that a predetermined multiple of the data length in the main scanning direction of a prescan image to be displayed matches the data length of a packet to be transmitted. The image processing system according to claim 22, wherein: 37. The apparatus according to claim 37, further comprising a size determining means for determining a packet size such that a predetermined number of times the data length of the packet to be transmitted matches the data length of the prescan image to be displayed in the main scanning direction. The image processing system according to claim 22, characterized in that: 38. Image data is received from an image reading apparatus having a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs, via the communication interface. Determining means for determining whether an error has occurred in receiving a data packet from the image reading device using the first transfer mode; and determining that the error has occurred by the determining means. If judged,
An information processing apparatus comprising: a retransmission request unit that requests retransmission of the errored data packet in the second transfer mode. 39. An image reading apparatus having a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs.
A method for controlling an information processing device that receives image data via the communication interface, the method further comprising: determining whether an error has occurred in receiving a data packet from the image reading device using the first transfer mode. A determining step, and when it is determined that an error has occurred in the determining step,
A retransmission requesting step of requesting retransmission of the errored data packet in the second transfer mode. 40. An image reading apparatus having a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs.
A storage medium storing a program code that functions as an information processing device that receives image data via the communication interface, wherein an error occurs in receiving a data packet from the image reading device using the first transfer mode. A program code of a determination step of determining whether or not an error has occurred;
And a program code for a retransmission requesting step for requesting retransmission of the errored data packet in the second transfer mode. 41. An image processing apparatus comprising an image data generating source and an information processing device connected via a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs. An image processing system, wherein the information processing device determines whether an error has occurred in receiving a data packet from the image reading device using the first transfer mode; and If you determine that an error has occurred,
An image processing system comprising: a retransmission request unit that requests retransmission of the errored data packet in the second transfer mode. 42. Image data is received from an image data source having a communication interface having a first transfer mode for guaranteeing a transfer band and a second transfer mode for performing a retransmission procedure when an error occurs, via the communication interface. A determination unit that determines whether an error has occurred in receiving a data packet from the image data generation source using the first transfer mode; and an error has occurred by the determination unit. Is determined,
An information processing apparatus comprising: a retransmission request unit that requests retransmission of the errored data packet in the second transfer mode.