JP4062747B2 - Image data transmission device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image data transmitting apparatus.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an image transmission system has been provided for capturing an image with a video camera or the like and displaying the captured image on a display of a display device disposed in a remote place, and the image transmission system includes the video camera. An image data transmitting device for converting an image captured by the method into compressed image data and transmitting the image, and an image data receiving device for receiving the transmitted compressed image data and displaying the image on the display according to the compressed image data .
[0003]
In the image data transmitting apparatus, a video signal such as an NTSC signal or a PAL signal corresponding to an image is generated by a video camera or the like, and the video signal is sent to an A / D converter, A / D conversion is performed by the A / D converter, and digital signals such as RGB signals and YUV signals are obtained. Subsequently, a pulse is formed in the timing signal by the CPU, and a digital signal is captured by the image encoding unit for each screen, that is, for each frame, at an image capture timing generated thereby. In this way, the image encoding unit captures an image.
[0004]
Then, the digital signal is encoded by the image encoding unit to become image data, is compressed, is sent to the transmission unit as compressed image data, and is synchronized with the transmission timing generated by the transmission unit. It is transmitted to the receiving device.
In this way, when the transmission of the compressed image data is completed, the CPU immediately generates the next image capture timing, and the digital signal is captured by the image encoding unit for the next frame image.
[0005]
In addition, the image image | photographed with the video camera etc. and the image displayed on a display consist of a some pixel comprised by a 640 * 480 matrix, for example.
[0006]
[Problems to be solved by the invention]
However, in the conventional image data transmitting apparatus, an operator operating a video camera or the like, for example, between the time when the image capture timing is generated and the time when the next image capture timing is generated. When the snap button for capturing the snap image of the transmitter of the image data transmitting device is operated to display the image that appears suddenly on the display as a snap image, the image capture timing can be generated. The transmission timing cannot be generated until the transmission of the compressed image data for the image of this frame is completed.
[0007]
By the way, in the image data transmitting apparatus, an image captured by a video camera or the like is captured by an image encoding unit and encoded into image data. The time until the image data is compressed is one frame. Per 1/30 second. On the other hand, the time from when the compressed image data sent to the transmission unit is transmitted to the image data receiving device and received by the image data receiving device, that is, the transmission time is the transmission path, the data of the compressed image data. For example, when a digital mobile phone is used, it takes about 1 to 180 seconds per frame although it varies depending on the amount.
[0008]
Therefore, even if the operator operates the snap button, the time until the snap image is displayed on the display becomes long, and the response of the image data transmitting apparatus to the operation is delayed.
Also, between the time when the image capture timing is generated and the time when the next image capture timing is generated, for example, the operator switches the resolution of the image displayed on the display, that is, the image quality, for example, When the image quality switching button is operated to change from a 640 × 480 pixel to a 320 × 480 pixel, an image capture timing can be generated, but the compressed image data of the image of the current frame can be generated. The transmission timing cannot be generated until the transmission is completed.
[0009]
Therefore, the time until the image after the image quality is switched is displayed on the display becomes long, and the response of the image data transmitting apparatus to the operation is delayed.
Therefore, when an image transmission interruption event occurs, such as displaying a snap image or switching image quality, it is possible to interrupt transmission immediately and generate an image capture timing to capture a new image. If transmission of the compressed image data for the image of the current frame is almost completed, it is necessary to re-encode, compress the image data, transmit the compressed image data, etc. for the image of the current frame Therefore, it takes a long time from when the image of the previous frame is displayed on the display to when the image of the next frame is displayed on the display.
[0010]
The present invention solves the problems of the conventional image data transmitting apparatus and can speed up the response to the operation. After the image of the previous frame is displayed on the display, the image of the next frame is displayed on the display. An object of the present invention is to provide an image data transmitting apparatus that can shorten the time until display.
[0011]
[Means for Solving the Problems]
For this purpose, in the image data transmitting apparatus of the present invention, an image capturing unit that captures an image and an image captured by the image capturing unit are captured at an image capture timing generated for each frame, and the image data is compressed. Originally generated after completion of transmission of compressed image data for a frame being transmitted when transmitting the compressed image data, compression means for converting to compressed image data, transmission means for transmitting the compressed image data, and the compressed image data When an image transmission interruption event occurs at a timing before the image capture timing, the next image capture timing is generated ahead of the original image capture timing, and it is generated ahead of schedule. The number representing the data amount of the compressed image data compressed by the intra-frame compression process for the image captured at the image capture timing. The interframe compression is based on the comparison between the amount of data required for transmission and the remaining amount of compressed image data being transmitted and the image captured at the original image capture timing and the image captured at the immediately preceding image capture timing. When the second required transmission data amount obtained by adding the data amount of the compressed image data compressed by the processing is compared, and the first required transmission data amount is smaller than the second required transmission data amount And a transmission interruption judging means for interrupting transmission of the compressed image data by the transmission means.
[0012]
The transmission unit transmits the compressed image data of the image captured at the image capture timing generated ahead when the transmission of the compressed image data is interrupted.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram of an image data transmitting apparatus according to the first embodiment of the present invention, and FIG. 2 is a diagram showing an image transmission system according to the first embodiment of the present invention.
In FIG. 2, reference numeral 11 denotes an image data transmitting device that converts a captured image into compressed image data and transmits the image. The image data transmitting device 11 includes a video camera 12 as an imaging unit that captures an image, and the video camera. 12, a transmitter 13 that converts a captured image into compressed image data, and a transmission unit 15 as a transmission unit such as a digital mobile phone that transmits the compressed image data in synchronization with the transmission timing. Have The video camera 12 includes a main body 12a and a controller 12b, and a modem 99 is connected to the transmitter 13.
[0018]
Reference numeral 16 denotes an image data receiving apparatus connected to the image data transmitting apparatus 11 via a telephone line 17 such as a mobile telephone line for performing wireless communication. The image data receiving apparatus 16 includes compressed image data. Receiving unit 31 such as a digital mobile phone, modem 32, and received compressed image data are decompressed and decoded into a digital signal, and the digital signal is D / A converted into an analog signal, It has a receiving / display unit 18 such as a personal computer for displaying. The reception / display unit 18 includes a main body 21 and a display device 22, and a display 23 is disposed on the display device 22. An operation unit 19 is formed on the main body 21. In the present embodiment, the transmission unit 15 and the reception unit 31 are configured by wireless communication such as a digital mobile phone, but can also be configured by wired communication such as an ordinary telephone. In this case, the telephone line 17 is constituted by a general public line, an ISDN line, etc. for performing wired communication.
[0019]
Next, the image data transmission device 11 will be described.
In FIG. 1, 12 is a video camera, 13 is a transmitter, and 15 is a transmitter. The transmitter 13 is an A / D converter 24 for A / D converting a video signal into a digital signal, and captures the digital signal. The image encoding unit 25, the CPU 26, the block memory 27 connected to the image encoding unit 25, and the block memory 27 as compression means for compressing the image data into compressed image data, It consists of a RAM 28 and a ROM 29 connected to the CPU 26, respectively. The CPU 26 uses the RAM 28 as a working area and performs various controls according to programs and data stored in the ROM 29.
[0020]
In the video camera 12, for example, a video signal such as an NTSC signal and a PAL signal corresponding to a photographed image is generated at a speed of 30 [frames / second]. The video signal is A / D converted by the A / D converter 24 to become a digital signal such as an RGB signal or a YUV signal.
A timing signal (not shown) built in the CPU 26 generates a timing signal, and a pulse is formed in the timing signal, thereby generating an image capture timing. Each time the image capture timing is generated, the digital signal is captured by the image encoding unit 25 for each frame. Next, the image encoding unit 25 encodes the digital signal based on an instruction from the CPU 26 to form image data, and compresses the image data into compressed image data. The image converted into the digital signal in this way is captured by the image encoding unit 25.
[0021]
The matrix constituted by the image data is formed in correspondence with the image quality designated by the operator. Therefore, when the operator switches the image quality, the matrix is changed to various sizes, for example, 320 × 480. For this purpose, an image quality switching button (not shown) is provided on the transmitter 13, and an operator can instruct switching of the image quality by operating the image quality button. An image quality button for switching image quality can also be formed on the reception / display unit 18.
[0022]
By the way, the image encoding unit 25 encodes a digital signal into image data. At this time, according to an instruction from the CPU 26, the image data is compressed into a compressed image data by a predetermined compression method. In this case, various existing compression methods, for example, the FST compression method are employed (see Japanese Patent Laid-Open No. 5-227547).
In the FST compression method, for example, when the digital signal is composed of RGB signals, each image data constituting the matrix after encoding is 5 bits set for each element R, G, B. The total number of bits is 15.
[0023]
Then, in order to compress the image data, the image encoding unit 25 divides the image data matrix into a plurality of blocks made up of, for example, 4 × 2 sub-matrices, and performs compression processing for each block. . In this case, since the number of bits of each image data is 15, the number of bits of the bit data constituting one block of image data is
15 × 4 × 2 = 120
become.
[0024]
By the way, the FST compression method is performed on the premise that there are only two colors in one block and the luminance level is constant in each color. Therefore, when the FST compression method is performed, first, the luminance level is examined for each of eight image data (hereinafter referred to as “pixels”) constituting each block, and each pixel is divided into two groups of light and dark. Next, a color representative of each group is determined, and an 8-bit bitmap representing which group color belongs to “1” or “0” for all pixels in the block is formed.
[0025]
Accordingly, the number of bits of the bit data representing the information amount of one block after the FST compression method is performed is the number of bits for representing the color representing each group.
2 × 15 = 30
Is the number of bits in the bitmap, that is, the number obtained by adding 8
30 + 8 = 38
become. By performing such compression processing, non-redundancy information in each block is specified and coded, and the image data is compressed from 120-bit bit data to 38-bit compressed image data. The compressed image data is written in the block memory 27.
[0026]
Further, in the FST compression method, intra-frame compression processing that takes a correlation between blocks in a frame is performed as the first compression processing, or intra-frame compression processing that takes a correlation between blocks in each frame and This can be performed as a second compression process including an inter-frame compression process that takes a correlation between frames.
[0027]
FIG. 3 is a first diagram illustrating intra-frame compression processing and inter-frame compression processing in the FST compression method. FIG. 4 is a second diagram illustrating intra-frame compression processing and inter-frame compression processing in the FST compression method. These are the time charts which show operation | movement of the image data transmission apparatus in the 1st Embodiment of this invention.
In the figure, f _i (I = 1, 2,..., N) is the i-th frame among n frames sequentially formed, and f _P Is the frame f _i Of the current frame, f _O Is the frame f _i Of the current frame f _P This is the previous frame.
[0028]
B _P Is the current block to be subjected to the first and second compression processing, b ₁ Is the current block b _P A block located in the upper left with respect to b ₂ Is the current block b _P A block located directly above b, _Three Is the current block b _P A block located in the upper right with respect to b _Four Is the current block b _P The block located to the left of b _Five Is the previous frame f _O In the current block b _P Is a block corresponding to.
[0029]
Usually each block b ₁ ~ B _Five Image data and current block b _P The correlation with the image data is relatively large. Therefore, in the intra-frame compression processing, each block b ₁ ~ B _Four Block data and current block b _P In the inter-frame compression processing, the block b _Five Block data and current block b _P Are compared with the block data.
[0030]
In the present embodiment, image data can be compressed in each mode of the first and second compression processes. In the first compression process, the image data is compressed only by the intra-frame compression process, and each block b ₁ ~ B _Four Block data and current block b _P The result of comparison with the block data is the first compressed image data of 5 bits. In this way, the current block b is determined by the first compressed image data. _P The image data within can be represented.
[0031]
On the other hand, in the second compression processing, intra-frame compression processing and inter-frame compression processing are performed. ₁ ~ B _Five Block data and current block b _P The result of comparison with the block data is converted to the 5-bit second compressed image data. Therefore, the current block b is determined by the second compressed image data. _P The image data within can be represented.
[0032]
In the block memory 27 (FIG. 1), each block data is sequentially rewritten, and each block b ₁ ~ B _Five Are read from the block memory 27 by the image encoding unit 25, and the current block b is read out. _P Is compared with the block data.
In this way, non-redundancy information within and between frames is identified and coded by compressing image data in each mode of the second compression process and the first compression process, and a 38-bit image is obtained. The data is compressed into 5-bit compressed image data.
[0033]
Note that an MPEG compression method, a TIM compression method, or the like may be employed instead of the FST compression method.
In this way, when the image data is compressed, the CPU 26 reads the compressed image data and sends it to the transmission unit 15. The transmitting unit 15 puts the compressed image data on the transmission signal and sends it to the image data receiving device 16 (FIG. 2) in real time. In this way, when transmission of compressed image data for one frame is completed, the CPU 26 immediately generates the next image capture timing, and the digital signal is captured by the image encoding unit 25 for the next frame image. It is.
[0034]
Normally, as shown in FIG. 5, image transmission timings t1, t2,... Are generated every time transmission of compressed image data for one frame is completed, but a certain image capturing timing is generated. Until the next image capture timing is generated, for example, an operator operating the video camera 12 or the like tries to display an image that appears suddenly on the display 23 as a snap image. If an event for interrupting image transmission occurs by operating a snap button for capturing a snap image (not shown), the next image capture timing may be advanced and the transmission of compressed image data may be interrupted as necessary. It can be done. Therefore, when an image transmission interruption event occurs, a timing change process is performed by a transmission interruption determination unit (not shown) of the CPU 26.
[0035]
FIG. 6 is a flowchart showing a timing change processing subroutine according to the first embodiment of the present invention, and FIG. 7 is a time chart showing the operation of the image data transmitting apparatus according to the first embodiment of the present invention.
7, t11, t12,... Are image capture timings, τ11 is a timing at which an image transmission interruption event occurs, and τ12 is an image capture timing that is originally generated.
[0036]
In this case, after the digital signal is captured by the image encoding unit 25 (FIG. 1) at the image capture timing t11, the compressed image data is transmitted, and when the transmission of the compressed image data is completed, the original image capture is performed. The capture timing τ12 is generated, but before the original image capture timing τ12 is generated, the operator operating the video camera 12 uses the suddenly appearing image as a snap image on the display 23 (FIG. 2). When a snap button for capturing a snap image (not shown) of the transmitter 13 is operated at the timing τ11 to display, the CPU 26 stores the compressed image data stored in the block memory 27 in the RAM 28 at the image capturing timing t12. At the same time, take a snap image, compress the image data by the second compression process, compress Storing the second compressed image data in the RAM 28. Subsequently, without requiring the operation of a snap button, the image encoding unit 25 takes in the snap image again, compresses the image data by the first compression processing, and the first compressed image data after the compression Is stored in the RAM 28. In the present embodiment, the snap button is disposed in the transmitter 13, but may be disposed in the reception / display unit 18.
[0037]
Next, the CPU 26 interrupts the transmission of the compressed image data and starts encoding of the digital signal and compression of the image data for the snap image, or the original image capture timing τ12 without interrupting the transmission of the compressed image data. It is then determined whether to start encoding digital signals, compressing image data, etc. for the snap image. Therefore, the remaining amount of the compressed image data being transmitted at the timing τ 11 is c, the data amount of the second compressed image data stored in the RAM 28 is a, and the data of the first compressed image data stored in the RAM 28 When the amount is b, the CPU 26 has a data amount b as the first required transmission data amount and a data amount (a + c) as the second required transmission data amount obtained by adding the remaining amount c to the data amount a. ) And
b <a + c
It is determined whether or not. And
b <a + c
In this case, the CPU 26 gives an instruction to the transmission unit 15 to interrupt the transmission of the compressed image data, and transmits the first compressed image data by the transmission unit 15 as shown in FIG. Thereafter, the image data is compressed by the second compression process.
[0038]
on the other hand,
b ≧ a + c
The original image capture timing τ12 is generated without interrupting transmission of the compressed image data, and the image data is compressed by the second compression process at the original image capture timing τ12. The second compressed image data is transmitted. In this case, since the second compressed image data is replaced with the first compressed image data in the block memory 27, the image encoding unit 25 stores the second compressed image data stored in the RAM 28. Once (once) stored in the block memory 27, the second compressed image data is transmitted in synchronization with the transmission timing. Thereafter, the image data is compressed by the second compression process.
[0039]
by the way,
b <a + c
In this case, even if transmission of compressed image data is interrupted, transmission of compressed image data for the next frame image can be completed relatively quickly. Therefore, the operator can quickly view the requested image.
[0040]
on the other hand,
b ≧ a + c
In this case, transmission can be continued without interrupting transmission, and the image requested by capturing the next image at the original image capture timing τ12 can be viewed earlier. In addition, it is possible to shorten the waiting time from when the previous frame image is displayed until the next frame image is displayed.
[0041]
In the present embodiment, the data amount b is compared with the data amount (a + c) obtained by adding the remaining amount c to the data amount a. However, the data amount b is transmitted. It is also possible to compare the required first transmission time and the second transmission time required to transmit the data amount (a + c).
Next, a flowchart will be described.
Step S1: The image encoding unit 25 takes in the snap image and compresses the image data by the second compression processing.
Step S2: The second compressed image data (data amount a) is stored in the RAM 28.
Step S3: The image encoding unit 25 takes in the snap image and compresses the image data by the first compression processing.
Step S4: The first compressed image data (data amount b) is stored in the RAM 28.
Step S5: It is determined whether the data amount b is smaller than the data amount (a + c). If the data amount b is smaller than the data amount (a + c), the process proceeds to step S6. If the data amount b is greater than or equal to the data amount (a + c), the process proceeds to step S8.
Step S6: An instruction is given to the transmission unit 15 to interrupt transmission of the compressed image data.
Step S7: The first compressed image data is transmitted.
Step S8: The second compressed image data is stored in the block memory 27.
Step S9: An instruction is given to the transmission unit 15 to transmit the second compressed image data.
[0042]
Next, a second embodiment will be described.
FIG. 8 is a flowchart showing the operation of the image data transmitting apparatus according to the second embodiment of the present invention.
In this case, when an image transmission interruption cause occurs, a timing change process is performed by a transmission interruption determination unit (not shown) of the CPU 26 (FIG. 1).
Step S11 The image encoding unit 25 takes in an image, encodes it into image data, and compresses the image data into compressed image data.
Step S12: It is determined whether or not an image quality switching instruction has been issued. If the switching of the image is instructed, the process proceeds to step S13. If the switching is not instructed, the process proceeds to step S14.
Step S13: Transmission interruption determination means performs timing change processing.
Step S14: The compressed image data is transmitted.
Step S15: It is determined whether or not the transmission of the compressed image data has been completed. If the transmission is completed, the process returns to step S11. If the transmission is not completed, the process returns to step S12.
[0043]
Next, the timing change process in step S13 of FIG. 8 will be described.
FIG. 9 is a flowchart showing a subroutine of timing change processing according to the second embodiment of the present invention. FIG. 10 is a first time chart showing the operation of the image data transmitting apparatus according to the second embodiment of the present invention. 11 is a second time chart showing the operation of the image data transmitting apparatus according to the second embodiment of the present invention.
[0044]
10, t21, t22,... Are image capture timings, τ21 is a timing at which an image transmission interruption event occurs, and τ22 is an image capture timing that is originally generated.
In this case, the original image capture timing τ22 is generated when the transmission of the compressed image data ends after the digital signal is captured by the image encoding unit 25 (FIG. 1) at the image capture timing t21. Before the original image capture timing τ22 is generated, the operator tries to switch the image quality of the image displayed on the display 23 (FIG. 2), and the image quality (not shown) for switching the image quality of the operation unit 19 at the timing τ21. When the button is operated and a predetermined command is sent to the transmitter 13, the CPU 26 transmits the time from the timing τ21 to the original image capture timing τ22, that is, the remaining amount of compressed image data being transmitted. The required transmission time δ is calculated, and it is determined whether the transmission time δ is equal to or greater than a set value. The required transmission time δ is calculated based on the remaining amount of compressed image data being transmitted at the timing τ21 and the transmission speed.
[0045]
If the required transmission time δ is equal to or longer than the set value, the transmission interruption determining means (not shown) of the CPU 26 gives an instruction to the transmission unit 15 to interrupt the transmission and, as shown in FIG. The image encoding unit 25 captures an image of the next frame at the image capture timing t22. Therefore, before the original image capture timing τ22 is generated, encoding of a digital signal, compression of image data, and the like can be started for the next frame image. As a result, the operator can quickly view the requested image.
[0046]
On the other hand, when the transmission required time δ is shorter than the set value, the CPU 26 switches the image quality without interrupting the transmission of the image data.
That is, in FIG. 11, t31, t32,... Are image capture timings, and τ31 is a timing at which an image transmission interruption cause occurs.
In this case, after the digital signal is captured by the image encoding unit 25 (FIG. 1) at the image capture timing t31, the next image capture timing t32 is generated when transmission of the compressed image data ends. Then, before the image capture timing t32 is generated, when the operator operates the image quality button of the operation unit 19 at timing τ31 in order to switch the image quality of the image displayed on the display 23 (FIG. 2), the timing When the required transmission time δ from τ31 to the image capture timing t32 is shorter than the set value, the image capture timing t32 is generated as it is.
[0047]
As described above, when there is almost no remaining compressed image data being transmitted at the timing τ31 and the transmission of the compressed image data is almost finished, the operator cannot quickly view the requested image. The waiting time from when the image is displayed until the next frame image is displayed can be shortened.
In the present embodiment, the required transmission time δ is compared with the set value, but the remaining amount of compressed image data being transmitted and the set value are calculated without calculating the required transmission time δ. Can also be compared.
[0048]
Next, the flowchart of FIG. 9 will be described.
Step S13-1: The CPU 26 calculates the required transmission time δ based on the remaining amount of compressed image data being transmitted and the transmission speed.
Step S13-2: The transmission interruption determining means determines whether the required transmission time δ is equal to or greater than a set value. If the required transmission time δ is greater than or equal to the set value, the process proceeds to step S13-3. If the required transmission time δ is shorter than the set value, the process proceeds to step S13-5.
Step S13-3: The CPU 26 gives an instruction to the transmission unit 15 and interrupts the transmission of the compressed image data.
Step S13-4: The image encoding unit 25 captures a digital signal for the next frame image.
Step S13-5: The CPU 26 switches the image quality without interrupting the transmission of the compressed image data.
[0049]
In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.
[0050]
【The invention's effect】
As described above in detail, according to the present invention, in the image data transmitting apparatus, an image capturing unit that captures an image and an image capture timing at which an image captured by the image capturing unit is generated for each frame. A compression unit that captures and compresses image data into compressed image data; a transmission unit that transmits the compressed image data; and a compressed image data for a frame that is being transmitted when the compressed image data is transmitted. If an image transmission interruption event occurs at a timing prior to the original image capture timing that occurs after the transmission is completed, the next image capture timing is generated before the original image capture timing. Compressed image data compressed by intra-frame compression processing for images captured at the image capture timing generated ahead of schedule. An image captured at the original image capture timing and an image captured at the immediately preceding image capture timing in the first required transmission data amount representing the data amount of the data and the remaining amount of compressed image data being transmitted And the second required transmission data amount obtained by adding the data amount of the compressed image data compressed by the inter-frame compression process based on the comparison with the first required transmission data amount. And a transmission interruption determination unit that interrupts transmission of the compressed image data by the transmission unit when the amount of data required for transmission is smaller.
[0051]
The transmission unit transmits the compressed image data of the image captured at the image capture timing generated ahead when the transmission of the compressed image data is interrupted.
In this case, when an image transmission interruption event occurs, the transmission interruption determination unit compares the first required transmission data amount with the second required transmission data amount, and the first required transmission data amount is the second required transmission data amount. When the amount of data required for transmission is smaller, the transmission of the compressed image data by the transmission means is interrupted.
[0052]
Therefore, when the transmission of the compressed image data is interrupted, the transmission of the compressed image data for the next frame image can be completed relatively quickly, so that the requested image can be viewed quickly.
If the transmission of compressed image data is not interrupted, the requested image cannot be viewed quickly, but the waiting time until the next frame image is displayed after the previous frame image is displayed is shortened. be able to.
[Brief description of the drawings]
FIG. 1 is a block diagram of an image data transmitting apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an image transmission system according to the first embodiment of the present invention.
FIG. 3 is a first diagram illustrating intra-frame compression processing and inter-frame compression processing in the FST compression method.
FIG. 4 is a second diagram illustrating intra-frame compression processing and inter-frame compression processing in the FST compression method.
FIG. 5 is a time chart showing an operation of the image data transmitting apparatus according to the first embodiment of the present invention.
FIG. 6 is a flowchart showing a subroutine of timing change processing according to the first embodiment of the present invention.
FIG. 7 is a time chart showing an operation of the image data transmitting apparatus according to the first embodiment of the present invention.
FIG. 8 is a flowchart showing an operation of the image data transmitting apparatus according to the second embodiment of the present invention.
FIG. 9 is a flowchart illustrating a subroutine of timing change processing according to the second embodiment of the present invention.
FIG. 10 is a first time chart showing an operation of the image data transmitting apparatus according to the second embodiment of the present invention.
FIG. 11 is a second time chart showing the operation of the image data transmitting apparatus according to the second embodiment of the present invention.
[Explanation of symbols]
11 Image data transmitter
12 Video camera
15 Transmitter
25 Image encoding unit
26 CPU
t12, t22 Image capture timing
δ Time required for transmission
τ12, τ22 Original image capture timing

Claims (2)

Image capturing means for capturing an image, compression means for capturing an image captured by the image capturing means at an image capture timing generated for each frame, and compressing the image data into compressed image data, and the compressed image data And transmitting means for transmitting the image at a timing prior to the original image capture timing that occurs after the transmission of the compressed image data for the frame being transmitted ends when transmitting the compressed image data. In the case of an interruption cause, the next image capture timing is generated ahead of the original image capture timing, and the image is captured at the image capture timing generated in advance . a first transmission required data value representing the data quantity of the compressed image data compressed by the compression process, the remaining of the compressed image data being transmitted A, by adding the data amount of the compressed image data compressed by the compression processing between based rather frames on a comparison of the image with the captured in the original image capture timing and an image captured by the image pickup timing of the immediately preceding comparing the second transmission required data amount obtained Te, when the first transmission required data amount is smaller than the second transmission required data amount, it suspends the transmission of the compressed image data by the transmitting means which has a transmit interrupt determining means, said transmitting means is transmitted when the transmission of the compressed image data is interrupted, the compressed image data for the captured image by the image pickup timing that is allowed to occur ahead of schedule image data transmission apparatus, characterized by. Imaging means for capturing the images, the image taken by the image pickup means captures the image capture timing is generated for each frame, and compressing means for compressing image data by compressing the image data, the compressed image transmitting means for transmitting data, while sending the compressed image data, the image at the timing before the actual image capture timing at which the transmission of the compressed image data for a frame during transmission occurs after the completion frame when the transmission interruption event occurs, the images captured by the prior original image capture timing is generated by ahead of the next image capture timing, the image pickup timing that is allowed to occur ahead of schedule first transmission duration required to transmit the data amount of the compressed image data compressed by the inner compression, pressure in the transmission The remaining amount of the image data, image and the compressed image data compressed by the compression processing between based rather frames on a comparison of the captured image by the image pickup timing immediately before being taken in by the original image capture timing Compared with the second transmission time required to transmit the data amount obtained by adding the data amount, and when the first transmission time is shorter than the second transmission time, which has a signal interruption determining means sending you suspend transmission of the compressed image data by said transmitting means, said transmitting means, when the transmission of the compressed image data is interrupted, the image capture that is allowed to occur ahead of schedule An image data transmitting apparatus that transmits compressed image data of an image captured at timing.

Images