JP5130839B2 - Image information compression and transfer method and image transfer apparatus - Google Patents

Description

  The present invention relates to a method for transferring design information created by a CAD system, and more particularly, a method and an image transfer device for efficiently compressing and transferring CAD image data having complicated and large amount of wiring information such as a telecommunication device. It is about.

  Currently, a CAD (Computer Aided Design) system is indispensable in the development of mechanical products and devices. As a form of using this CAD, a form of CAD-ASP (CAD-Application Service Providing) has been used in recent years. In this method, design data (image data) creation / editing / simulation is performed by a server of a CAD system center, and a client connected via a network only performs mouse operation and display at a client terminal. On the other hand, application processing of images in the Unix (registered trademark) system is performed on image data by a command (drawing command: line drawing, circumferential drawing, rectangular drawing) or the like obtained by dividing individual image elements. First, an image drawing command as a premise of the invention will be described.

FIG. 7 is a diagram illustrating image elements and drawing command examples. An example of an image element constituting an image and its drawing command is shown. The drawing command has a one-to-one correspondence with the drawing element. As an example, a line segment, a rectangle, and an arc will be described.
1) Line segment: (X1, Y1, X2, Y2)
A line segment connecting the coordinates (X1, Y1) and (X2, Y2) from the image origin, and the drawing command is described by (X1, Y1, X2, Y2).
2) Rectangle: (X, Y, width, height)
A rectangle is expressed by coordinates (X, Y) from the image reference point and the width and height of the rectangle, and a drawing command is described by (X, Y, width, height).
3) Arc: (X, Y, width, height, angle 1, angle 2)
An arc centered at coordinates (X, Y) from the image reference point is decomposed into a width, a height and an angle 1 and an angle 2, and (X, Y, width, height, angle 1 and angle 2) are used as drawing commands. Describe.

FIG. 6 is a diagram showing a system configuration of the present invention and a conventional drawing information transfer method. The CAD system center server 4 transfers drawing data to a plurality of client terminals 6 (a plurality of client terminals are represented by 6) via the communication network 5. The server 4 executes image processing such as image simulation, image editing (drawing decomposition), and the client terminal 6 displays an image on the display unit and executes a mouse operation. A description will be given of matters relating to transfer of a drawing command which is an object of the present invention.
1) The server 4 decomposes the image by a CAD processing application program. The image “A” in FIG. 6 is decomposed into three line segments and one rectangle. “B” is the drawing command. For example, the command Ca1 for the line segment a1 is Ca1 = (6, 6, 10, 20) from the coordinates (6, 6), (10, 20) at both ends of the line segment. Similarly, the drawing command for the rectangle b1 is Cb1. = (0, 10, 20, 7).
2) The decomposed commands are transferred to the client terminal 6 in the order determined by the priority order of each image processing application program. For example, the data is transferred in the order of Ca1 and Cb1.
3) The client terminal 6 decodes and displays the image by the application program from the received drawing command, and performs a mouse operation and the like.

  As an image processing method, the drawing command method has an advantage that information is not lost by zooming compared to the bitmap type image processing method, but the image data becomes enormous regardless of the resolution of the client display device. There are drawbacks. For this reason, the drawing data capacity between the server and the client terminal becomes enormous, and there is a problem that it takes a long response time and it takes a long time to execute the application program.

  Patent Document 1 discloses a technique in which an image to be processed is held in a storage device, a predetermined process is performed within a predetermined time, and a compression process is performed according to a preset pixel thinning rate when the predetermined time has elapsed. Has been.

Patent Document 2 discloses a technique in which a rough whole image is transmitted at first, a fine image is gradually transmitted, and transmission is stopped when the image quality reaches a required quality on the receiving side.
JP 05-22777 A Japanese Patent Laid-Open No. 04-103257

  An object of the present invention is to transfer a drawing command when transferring image data (drawing command) related to wiring information of a telecommunication device or the like processed by a server of a CAD system center to a client terminal connected via a communication network. This is a time consuming problem.

  An object of the present invention is to effectively utilize the characteristics of a Unix (registered trademark) drawing command, compress the drawing data transfer capacity by thinning out the drawing command, and shorten the drawing command transfer time between the server and the client. An object of the present invention is to provide an image information compression method and an image transfer apparatus capable of efficiently executing an image processing application.

According to a first aspect of the present invention, there is provided an image information compression and transfer method for decomposing an image into image elements, receiving a drawing command representing the decomposed image element from a CAD system, and compressing and transferring the received drawing command to a client terminal. It is.

An image drawing command is received from the CAD system, the image is decomposed into rectangles, the number of drawing commands intersecting the divided rectangles for each divided rectangle is calculated, and the drawing commands received from the CAD system are received in the order of reception. For each of the divided rectangles, at most, the drawing commands that intersect the calculated divided rectangles are transferred to the client terminal.

According to the first invention, the drawing commands received from the CAD system are thinned out, the number of drawing commands to be transferred to the client terminal is restricted by the number of intersections, compressed and transferred to the client terminal, and the image transfer can be accelerated.

A second invention is an image transfer apparatus that decomposes an image into image elements, receives a drawing command representing the decomposed image element from a CAD system, and compresses and transfers the received drawing command to a client terminal. .

  The image transfer device includes means for receiving an image drawing command from the image processing system, means for dividing the image into rectangles, calculating means for calculating the number of the received drawing commands intersecting the divided rectangles, and for each divided rectangle. Means for setting the maximum number of transmissions for transmitting the drawing command, up to the maximum number of transmissions or the calculated number of intersections for each of the set divided rectangles in the order of reception of the drawing commands received from the image processing system; Means for transferring a number of drawing commands to the client terminal.

  According to the fourth aspect of the present invention, it is possible to realize an image transfer apparatus that can thin out drawing commands received from the image processing system, compress them and transfer them to the client terminal, and increase the image transfer speed.

  According to the present invention, in the execution of image data processing by a drawing command via a communication network between a server and a client terminal, the characteristics of the drawing command are effectively used, and the drawing command transfer time between the server and the client terminal is shortened. The application program for image processing can be executed efficiently.

Example 1
FIG. 1 is a diagram showing a block configuration of an image transfer apparatus according to an embodiment of the present invention. The CAD system is connected between the image transfer apparatus 1, the server 2, and a plurality of client terminals 3 (here, one client terminal is representatively displayed) via a communication network (not shown), and image processing is performed by a CAD application program. It is a system that performs.

In the CAD system, the image transfer device 1 receives the drawing commands that have been decomposed into the image elements processed by the server 2 and assigned the transfer order, executes the compression processing of the drawing commands to be transferred, and sends the drawing data to the client terminal 3. It is a device to transfer. The image transfer apparatus 1 includes an input interface 21 serving as an interface with a server, a cross analysis / compression processing unit 22 that performs compression processing by thinning out image data, a memory 23 that holds drawing information, and a client terminal 3 via a communication network. An output interface 23 of the interface is used. Further, an image display unit (not shown) is provided, and a drawing command for an area determined to be prioritized by manual determination from an image can be selected. Note that these image processing, transfer control, and the like are performed together with a CPU (not shown). The processing content of each part is demonstrated.
1) Input interface 21
It is an interface with the server 2 and obtains drawing information such as a drawing command number, a drawing command type, a drawing color, a paint flag, and a drawing command (the reception order is a priority order) from the server 2.
2) Intersection analysis / compression processor 22
The size (known) of one screen is divided into rectangles, the number of drawing commands intersecting each divided rectangle is calculated from the coordinate information of the drawing commands from the server 2, and drawing command thinning / compression processing is performed. Further, the number of transfers to the client terminal 3 is set, and a drawing command data and drawing data table described in FIG. 2 is created and held in the memory 23.
3) Memory 23
Holds drawing command data and drawing data table.
4) Output interface 24
The drawing command subjected to the thinning / compression processing by the intersection analysis / compression processing unit 22 is transferred to the client terminal 3.

FIG. 2 is a diagram showing drawing command data and drawing data examples applied to the present invention. Drawing command data is shown in 1) and drawing data is shown in 2). 2) describes the correspondence with the procedures in FIGS. 3 and 4 described later, and 2-1) describes the correspondence with the procedure in FIG. 3 and 2-2) separately describes the correspondence with FIG. The contents of this table will be described in conjunction with the steps of the drawing information compression procedure of FIGS.
1) Drawing command data Drawing command data includes a drawing command number, a drawing command type, a drawing color, a drawing fill flag, a drawing command, and a processing flag. A drawing command number, a drawing command type, a drawing color, a paint flag, and drawing data are obtained from the server 2 as drawing information, and a drawing command data table to which a processing flag described according to compression processing is added is created and stored in a memory. . Here, the drawing color is a drawing color, and the fill flag is a flag when the drawing is filled with a color.
2-1) Drawing data (corresponding to the procedure in FIG. 3)
Consists of a rectangle number and intersecting drawing command numbers. One screen is divided into rectangles, and drawing commands are created so that the order received from the server 2 (priority order) can be understood.
2-2) Drawing data (corresponding to the procedure in FIG. 4)
It consists of a rectangle number, the maximum number of transmissions, the number of intersections, and the drawing command number that intersects. One screen is divided into rectangles, and the number of intersections between the divided rectangles and the rectangles is calculated and created. The maximum number of transmissions is set for each divided rectangle.

FIG. 3 is a diagram showing a drawing information compression procedure (part 1). A procedure for compressing a drawing command processed by the server 2 is shown.
S1: The following initial settings are made and the screen is divided into rectangles.
A. Number of divisions to divide the screen into rectangles “L”
A. Maximum number of rectangular transmissions “N”
S2: Select the first rectangle in the preset order (eg, from the upper left to the next stage through the upper right) and do the following.
A. The number of transmissions SN is set to “0”. (SN = 0)
A. The processing rectangle number Bk is set to “1”. (Bk = 1)
S3: Obtain drawing data with the highest priority in the rectangle.
S4: It is confirmed whether or not the drawing command for the acquired drawing data has been transmitted. Whether or not the transmission has been completed is confirmed by the processing flag 1) in FIG.
S5: The acquired drawing command is transmitted to the transmission destination, and the next calculation is performed.
A. “1” is added to the number of transmissions SN. (SN = SN + 1)
S6: It is determined whether the number of transmissions is “N” or less. If “N” or less, the process proceeds to S7. If it exceeds [N], the process proceeds to S9.
S7: It is determined whether there is drawing data in the rectangle. If there is drawing data, the process proceeds to S8, and if not, the process proceeds to S9.
S8: The drawing data of the next priority is acquired, and the process returns to S4.
S9: Bk = Bk + 1.
S10: It is determined whether the number of processed rectangles is within the number of rectangles “L”. If there is an unprocessed rectangle, the process proceeds to S11, and if not, the process ends.
S11: The next rectangle is acquired as k = k + 1, and the process returns to S3.

The above procedure will be described with reference to examples of 1) drawing command data and 2-1) drawing data (corresponding to the procedure of FIG. 3) in FIG.
1) “N” is set to “3” as the maximum number of transmissions. The number of divided rectangles is from L1 to L150.
2) Obtain and transmit C2 from the drawing command numbers C2, C3, C8, and C6 of the divided rectangle L1, and set the processing flag to “completed”.
3) Since the number of transmissions is less than the maximum number of transmissions “3”, C3 and C8 are transmitted. Set the sent processing flag to “completed”. C6 is not transmitted.
4) Next, it becomes L2, and C5 and C6 that have not been transmitted in L1 are transmitted from the drawing command numbers C2, C5, and C6 of L2, and the processing flag is updated to “completed”. In this case, the number of transmissions of L2 is “2”, the drawing command C2 is thinned out, and the transmission data capacity is compressed.
5) The transmission process is sequentially performed on the next divided rectangle.

Further, the image transfer device described above is provided with an image display unit, and after the screen in S1 of FIG. 3 is divided into rectangles, the user determines the transmission order of the divided rectangles from the images, the number of transmissions of the divided rectangles, The transmission order is determined and the drawing command for the corresponding rectangle is transmitted with priority.
(Example 2)
FIG. 4 is a diagram showing a drawing information compression procedure (part 2). For the first embodiment, a method for determining the number of transfers from the number of crossings is shown.
S21. Perform the following initial settings and divide the screen into rectangles.
A. Number of divisions to divide the screen into rectangles “L”
A. The maximum number of transmissions “Nk (k = 1 to L)” for each rectangle is determined.
S22: The number of drawing commands “Mk (k = 1 to L)” intersecting each rectangle is calculated.
S23: The first rectangle in the preset order (eg, from the upper left to the next stage through the upper right) is selected, and the following is performed.
A. The number of transmissions SN is set to “1”. (SN = 1)
A. The processing rectangle number BK is set to “1”. (Bk = 1)
C. The selected rectangle number Lk is set to “1”. (K = 1)
S24: The drawing data with the highest priority in the rectangle is acquired.
S25: It is determined from the processing flag whether the drawing command for the acquired drawing data has been transmitted. If transmission has not been performed, the process proceeds to S26. If not, the process proceeds to S27.
S26: The acquired drawing command is transmitted to the transmission destination, and the next calculation is performed.
A. “1” is added to the number of transmissions SN. (SN = SN + 1)
S27: If SN ≦ N and SN ≦ Mk, proceed to S28, otherwise proceed to S30.
S28: It is determined whether there is drawing data in the rectangle. If there is drawing data, the process proceeds to S29. If not, the process proceeds to S30.
S29: The drawing data of the next priority is acquired, and the process returns to S25.
S30: Bk = Bk + 1.
S31: It is determined whether the number of processed rectangles is within the number of rectangles “L”. If there is an unprocessed rectangle, the process proceeds to S11, and if not, the process ends.
S32: The next rectangle is acquired as k = k + 1, and the process returns to S24.

The above procedure will be described with reference to examples of 1) drawing command data and 2-2) drawing data (corresponding to the procedure of FIG. 4) in FIG.
1) The number of divided rectangles is from L1 to L150. Set the maximum number of transmissions for each divided rectangle and add it to the table. L1, L2, and L3 are “1”, and L4 is “2”.
2) The number of drawing commands that intersect each rectangle is calculated and described in the item of the number of intersections in 3) of FIG. In the case of FIG. 2, for example, the numbers of intersections of L1 and L2 are “2” and “3”, respectively.
3) From the drawing command numbers C2 and C3 of the divided rectangle L1, C2 is acquired and transmitted from the maximum transmission count “1”, and the processing flag is set to “completed”.
4) Next, it becomes L2, and since the maximum number of transmissions is “1” from the drawing command numbers C2, C4, and C5 of L2, C4 having a high priority among the transmissions “not yet” is transmitted in L1, and the processing flag of C4 is set to “ To "Done".
5) Since L3 has the number of intersections “0”, there is no transmission processing.
6) For L4, C1 and C3 are transmitted from the maximum number of transmissions “2”, and the processing flag is set to “completed”.
7) The transmission process is sequentially performed on the next divided rectangle.

  FIG. 5 is a diagram for explaining an example of the number of intersections between a divided rectangle and a drawing command. There are drawing commands Cc1, Cc2, Cc3, and Cc4 on the screen. Drawing commands Cc2 and Cc3 intersect the rectangle number L1, and the number of intersections is “2”. Similarly, L2 is the number of intersections 3 of Cc2, Cc3, and Cc4. The description is omitted below.

FIG. 1 is a diagram showing a block configuration of an image transfer apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing drawing command data and drawing data examples applied to the present invention. FIG. 3 is a diagram showing a drawing information compression procedure (part 1). FIG. 4 is a diagram showing a drawing information compression procedure (part 2). FIG. 5 is a diagram for explaining an example of the number of intersections between a divided rectangle and a drawing command. FIG. 6 is a diagram showing a system configuration of the present invention and a conventional drawing information transfer method. FIG. 7 is a diagram illustrating image elements and drawing command examples.

Explanation of symbols

1 Image transfer device 2 Server 3 Client terminal 4 Server (conventional example)
5 Communication network 6 Client terminal (conventional example)
21 Input Interface 22 Cross Analysis Compression Processing Unit 23 Memory 24 Output Interface

Claims (2)

An image information compression and transfer method for decomposing an image into image elements, receiving a drawing command representing the decomposed image element from a CAD system, and compressing and transferring the received drawing command to a client terminal,
An image drawing command is received from the CAD system,
Break the image into rectangles,
For each divided rectangle , calculate the number of drawing commands that intersect the divided rectangle,
The prior Symbol dividing each rectangular in reception order of the drawing commands received from the CAD system, most image information compression, which comprises transferring the drawing command of the number of crosses each divided rectangle the calculated to the client terminal Transfer method. An image transfer device that decomposes an image into image elements, receives a drawing command representing the decomposed image element from a CAD system, and compresses and transfers the received drawing command to a client terminal,
The image transfer device includes:
Means for receiving an image drawing command from the CAD system;
Means for dividing an image into rectangles and calculating the number of received drawing commands that intersect the divided rectangles;
Means for setting a maximum number of transmissions for transmitting the drawing command for each of the divided rectangles;
With
For each of the set divided rectangles in the reception order of drawing commands received from the CAD system, at most the number of drawing commands or the number of drawing commands up to the calculated number of intersections are transferred to the client terminal. Image transfer device.

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