Abstract:
A method of and apparatus for transmitting video images preferably allows a specially trained individual to remotely supervise, instruct, and observe administration of medical tests conducted at remote locations. This apparatus preferably includes a source device, a transmitting device, and at least one remote receiving device. Preferably, the transmitting device and the remote receiving device communicate over a network such as the Internet Protocol network. Alternatively, the transmitting device and the receiving device communicate over any appropriate data network. The transmitting device transmits the video images to the remote receiving device either for live display through the source device or for pre-recorded display through a video recorder device. The remote receiving device is also capable of communicating with the transmitting device while simultaneously receiving video images. The source device is preferably a medical test device such as an ultrasound, a sonogram, an echocardiogram, an angioplastigram, and the like. This medical test device preferably generates video images for the transmitting device. The transmitting device captures the video images in real-time from the source device and compresses these video images utilizing a compression algorithm prior to transmitting data representing the video images to the remote receiving device. Remote users utilizing the remote receiving devices are capable of remotely controlling a number of parameters relating to the source device and the transmitting device. Such parameters include image quality, storage of the video images on the transmitting device, manipulating and controlling the source device, and the like.

Description:
RELATED APPLICATIONS 
     This application claims priority under 35 U.S.C. § 119(e) of the co-pending U.S. provisional application Ser. No. 60/085,818 filed on May 18, 1998 and entitled “APPARATUS FOR TRANSMITTING LIVE VIDEO IMAGES OVER A COMPUTER NETWORK TO MULTIPLE REMOTE RECEIVERS.” The provisional application Ser. No. 60/085,818 filed on May 18, 1998 and entitled “APPARATUS FOR TRANSMITTING LIVE VIDEO IMAGES OVER A COMPUTER NETWORK TO MULTIPLE REMOTE RECEIVERS” is also hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to the field of communications systems. More particularly, this invention relates to the field of video communications systems. 
     BACKGROUND OF THE INVENTION 
     In the last decade, there have been tremendous advances in medical devices which have greatly improved the ability to diagnose and treat patients. Ultrasounds, sonograms, echocardiograms, and angioplastigrams are just a few modern tools developed to accurately diagnose patients with coronary problems, kidney stones, tumors, and other diseases without conducting risky and expensive exploratory surgeries. These tools are especially useful because they have the capability of being more accurate than exploratory surgeries and do not pose an additional risk to patients. 
     Given the benefits of ultrasounds, sonograms, echocardiograms, and angioplastigrams, these tools are in widespread use in many hospitals, clinics, testing facilities, and individual doctors&#39; offices. Many doctors primarily base their diagnosis on the results from ultrasounds, sonograms, echocardiograms, and angioplastigrams. While these tools allow doctors to make their diagnosis without costly, risky, and time consuming exploratory surgeries, an error in administering an ultrasound, sonogram, echocardiogram, and angioplastigram can lead to a wrong diagnosis. A wrong diagnosis can be catastrophic for the patient. By receiving an incorrect diagnosis, the patient can potentially fail to receive needed medical treatment and/or be unnecessarily treated. Whether needed medical treatment is withheld or unnecessary medical treatment is given due to an erroneous test result from an ultrasound, sonogram, echocardiogram, or angioplastigram, the patient unnecessarily suffers. 
     While ultrasounds, sonograms, echocardiograms, and angioplastigrams are extremely useful tools to diagnose ailments in patients, any of these tools administered in an imprecise manner or in a wrong location will most likely produce a wrong result. This wrong result typically leads to the wrong diagnosis. Learning proper techniques and procedures in order to produce a correct result from an ultrasound, sonogram, echocardiogram, or angioplastigram requires extensive specialized training and many years of medical training. People who possess such specialized knowledge in administering ultrasounds, sonograms, echocardiograms, and angioplastigrams are in short supply and only administer a fraction of these tests which are performed each year. Instead, technicians with limited medical knowledge and limited training typically administer these tests. By not properly administering these tests, the results are often times inaccurate and lead to the wrong diagnosis. Furthermore, the tests are typically performed and later reviewed by the doctor after the patient has left the technician&#39;s office. 
     In order to achieve a higher accuracy rate, close supervision by a specially trained person is needed while a technician administers any one of these tests. However, having such a specially trained person at each of these tests while they are being administered is typically impractical and would result in much higher medical costs. 
     SUMMARY OF THE INVENTION 
     A method of and apparatus for transmitting video images preferably allows a specially trained individual to remotely supervise, instruct, and observe administration of medical tests conducted at remote locations. This apparatus preferably includes a source device, a transmitting device, and at least one remote receiving device. Preferably, the transmitting device and the remote receiving device communicate over a network such as the Internet Protocol network. Alternatively, the transmitting device and the receiving device communicate over any appropriate data network. The transmitting device transmits the video images to the remote receiving device either for live display through the source device or for pre-recorded display through a video recorder device. The remote receiving device is also capable of communicating with the transmitting device while simultaneously receiving video images. The source device is preferably a medical test device such as an ultrasound, a sonogram, an echocardiogram, an angioplastigram, and the like. This medical test device preferably generates video images for the transmitting device. The transmitting device captures the video images in real-time from the source device and compresses these video images utilizing a compression algorithm prior to transmitting data representing the video images to the remote receiving device. Remote users utilizing the remote receiving devices are capable of remotely controlling a number of parameters relating to the source device and the transmitting device. Such parameters include image quality, storage of the video images on the transmitting device, manipulating and controlling the source device, and the like. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a block diagram of a preferred embodiment of the present invention. 
         FIG. 2  illustrates a data flow diagram of the preferred embodiment of the present invention. 
         FIG. 3A  illustrates software code utilized during a compression process of the present invention. 
         FIG. 3B  illustrates a look-up table representing the software code utilized during the compression process of the present invention. 
         FIG. 4A  illustrates a flow chart showing the steps involved in the compression process within a compressor of the preferred embodiment. 
         FIG. 4B  illustrates a representative video image and a corresponding stream of pixels. 
         FIG. 5A  illustrates a data structure of the present invention. 
         FIG. 5B  illustrates the data structure configured to transmit a repeat command for the preferred embodiment. 
         FIG. 5C  illustrates the data structure for the preferred embodiment configured to transmit a line number which represents a pixel illumination intensity level. 
         FIG. 6  illustrates a sample data stream representing video pixels and a corresponding compressed data stream. 
         FIG. 7  illustrates software code utilized during a decompression process of the present invention. 
         FIG. 8A  illustrates a flow chart showing the steps for transmitting a stream of video images in real-time. 
         FIG. 8B  illustrates a flow chart showing the steps for transmitting a pre-recorded stream of video images. 
         FIG. 9  illustrates a flow chart showing the steps involved during the decompression process of the present invention. 
         FIG. 10  illustrates an uncompressed data stream, a corresponding compressed data stream, and a corresponding converted data stream of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates a video system  100  according to the present invention for transmitting video images from one location to another. The video system  100  preferably includes a video source  101 , a video cassette recorder  102 , a transmitter  103 , a recorded video device  104 , a computer network  105 , a plurality of receivers  106 , and data links  110 ,  115 ,  120 , and  125 . Preferably, the video source  101  includes the video cassette recorder  102  and is coupled to the transmitter  103  via the data link  110 . The data link  110  is preferably a Super-Video (S-Video) connection. The transmitter  103  is also preferably coupled to the recorded video device  104  and the computer network  105  via the data links  115  and  120 , respectively. 
     Preferably, the plurality of receivers  106  are coupled to the computer network  105  via the data links  125 . Each of the plurality of receivers  106  are preferably a computer system having a display, central processing unit, and input device. The data links  125  preferably link each of the plurality of receivers  106  to the computer network  105 . The data links  125  include any appropriate connection to the computer network  105  including T1 communication lines, DSL links, cellular links, microwave transmission, land lines, twisted pair cable, and the like. The video system  100  shown in  FIG. 1  is merely illustrative and is only meant to show the preferred embodiment of the present invention. In alternate embodiments, additional transmitters, video sources, and receivers could be included without departing from the spirit and scope of the video system  100 . Additionally, in an alternate embodiment, the transmitter  103  is included within the computer network  105  and functions as a server within the computer network  105 . 
     The video source  101  preferably provides the video system  100  with at least one video image. The video source  101  is capable of providing either a real-time video image or a pre-recorded video image. For example, to provide a real-time video image, the video source  101  preferably includes a real-time input device  130 . This real-time input device  130  is preferably a medical measurement device such as an ultrasound, sonogram, echocardiogram, angioplastigram, and the like. Alternatively, this real-time input device  130  could be any other appropriate image capturing device including a video camera and a still camera. The pre-recorded video image is preferably provided by the video cassette recorder  102 . Preferably, the video cassette recorder  102  is configured to record the real-time video images produced by the real-time input device  130  and play these pre-recorded video images at a later time. In addition to recording real-time video images and re-playing them, the video cassette recorder  102  is also preferably configured to accept and play a pre-recorded video cassette tape. The video source  101  is preferably configured to transfer the video image to the transmitter  103  via the data link  110 . 
     The recorded video device  104  is preferably coupled to the transmitter  103  via the data link  115 . Preferably, the recorded video device  104  stores video images received by the transmitter  103  for playback at a later time. The recorded video device  104  allows the transmitter  103  to distribute these video images to the plurality of receivers  106  at a later time. In addition, the recorded video device  104  also preferably serves as a mass storage device to store data that is unrelated to the video images. 
     The transmitter  103  preferably controls the flow of video images from both the video source  101  and the recorded video component  104  over the computer network  105  to any number of the plurality of receivers  106 . Preferably, the transmitter  103  compresses the video images prior to transmission to one of the plurality of receivers  106 , as will be described in detail below. Further, the transmitter  103  preferably monitors and selectively establishes connections with the computer network  105  over the data link  120 . 
     In the video system  100 , the computer network  105  is preferably an Internet Protocol network. In alternate embodiments, the computer network  105  is any appropriate data network. The computer network  105  is configured to transmit information between the plurality of receivers  106  and the transmitter  103  via the data links  125  and  120 , respectively. 
     The plurality of receivers  106  are preferably configured to selectively receive a stream of video images from the transmitter  103  via the data link  120 , the computer network  105 , and the appropriate data link  125 . For example, at least one of the plurality of receivers  106  is programmed to receive the stream of video images from the transmitter  103 . Accordingly, only the selected ones of the plurality of receivers  106  are capable of receiving the stream of video images from the transmitter  103 . In addition to receiving the stream of video images, the selected ones of the plurality of receivers  106  are also capable of transmitting instructions to the transmitter  103  via the data link  125 , the computer network  105 , and the data link  120 . 
       FIG. 2  illustrates a data path diagram of the preferred embodiment of the present invention.  FIG. 2  shows a video system  200  which is similar to the video system  100  shown in  FIG. 1 . The video system  200  preferably includes a transmitter  201 , a video source  203 , and a plurality of receivers  206 . The video system  200  shown in  FIG. 2  is merely illustrative and is meant to show the preferred embodiment of the present invention. In alternate embodiments, additional components such as transmitters, video sources, and receivers are included without departing from the spirit and scope of the video system  200 . 
     Preferably, the video source  203  is coupled to the transmitter  201  via a data link  250 . Upon direction from the transmitter  201 , the video source  203  is preferably configured to supply the transmitter  201 , through a video image capture device  202 , with a stream of video images through the data link  250 . 
     The transmitter  201  preferably includes the video image capture device  202 , a video server  212 , a video controller  209 , a listener device  213 , a recorded video transmitter  215 , and a plurality of socket handlers  214 . The video image capture device  202  also preferably includes a plurality of video settings  211  configured by the user. Preferably, the video image capture device  202  receives a stream of video images from the video source  203  and then transmits this stream of video images to the video server  212  via a data link  251 . The plurality of video settings  211  preferably allow adjustments to be made for modifying the stream of video images received by the video server  212 . Examples of adjustments included within the plurality of video settings  211  include brightness, contrast, hue, and the like. 
     The video server  212  preferably includes a compressor  204  and a buffer  223 . As the stream of video images are received by the video server  212 , the compressor  204  is configured to compress the stream of video images thereby creating a compressed stream of video images. As this compressed stream of video images is generated, the compressor  204  transmits each data block into the buffer  223 . Once the buffer  223  holds the compressed stream of video images having a predetermined number of data blocks, the compressed stream of video images is transmitted to one or more of the plurality of receivers  206 . The compressor  204  preferably utilizes a lossless compression algorithm to form the compressed stream of video images, as will be discussed in detail below. The compressor  204  preferably includes a buffer  222  for use with the compression algorithm. In an alternate embodiment, the compressor  204  utilizes a lossy algorithmic system to compress the flow of video images. 
     The video recorder  210  is capable of storing the stream of video images received by the transmitter  201  for transmission to one or more of the plurality of receivers  206  at a later time. Preferably, the stream of video images is compressed by the compressor  204  before being stored by the video recorder  210 . 
     In order to transmit the compressed stream of video images in real-time, the transmitter preferably transmits the compressed stream of video images through the listener device  213 . The listener device  213  is preferably configured to couple to the video server  212  via a data link  252 . Preferably, the listener device  213  is also coupled to the plurality of socket handlers  214  via the data links  253  and monitors the plurality of socket handlers  214  for any connection requests. Upon receiving a connection from appropriate ones of the plurality of receivers  206  through a socket handler  214 , the listener device  213  preferably informs the video server  212  via the data link  252 . In order to transmit the stream of video images to the appropriate ones of the plurality of receivers  206 , one of the plurality of socket handlers  214  couples to each of the appropriate ones of the plurality of receivers  206 . The connection(s) between the plurality of socket handlers  214  and the appropriate ones of the plurality of receivers  206  is (are) preferably formed through the computer network  105  ( FIG. 1 ). 
     In order to transmit the stream of video images at a later time, the video recorder  210  preferably stores the stream of video images. The video recorder  210  preferably includes an edit list  211  and is coupled to the video server  212  through a data link  256 . The video recorder  210  is also coupled to a recorded video transmitter  215  through a data link  257 . The video recorder  210  is preferably configured to control the initiation and termination of storing the stream of video images in response to instructions received by the video controller  209 . The recorded video device  208  is preferably a storage device coupled to the video recorder  210  and configured to store the stream of video images. Thus, the recorded video device  208  allows the video system  200  to save the stream of video images originating from the video source  203  and allows the video system  200  to transmit this saved stream of video images to appropriate ones of the plurality of receivers  206  at a later time. The recorded video device  208  is preferably coupled to the recorded video transmitter  215  and configured to transmit the saved stream of video images from the transmitter  201  to the appropriate ones of the plurality of receivers  206  over the appropriate recorded video pipe(s)  216 . 
     The plurality of receivers  206  preferably reside in a remote location relative to the transmitter  201 . Preferably, the plurality of receivers  206  selectively receive the flow of video images from the transmitter  201  and also selectively respond to the transmitter  201  with instructions. 
     Each of the plurality of receivers  206  preferably includes a video controller  207 , a video client  217 , and a video play device  219 . The video controller  207  preferably communicates with the video controller  209  of the transmitter  201  via a data link  220 . Preferably, the video controller  207  relays information regarding the frame size, frame rate, compression algorithm, and other parameters being transmitted to the video controller  207  via the data link  220 . Thus, a user interfacing with one of the plurality of receivers  206  is able to modify the frame size, frame rate, compression algorithm, and other parameters of the incoming stream of video images to one of the plurality of receivers  206 . Since the plurality of receivers  206  and the transmitter  201  are preferably located in remote locations, by interfacing with the video controller  207 , the user is able to remotely control video parameters such as frame size, frame rate, compression algorithm, and the like which are included within the video settings  211  at the transmitter  201 . 
     When receiving the compressed stream of video images in real-time from the video server  212  in the transmitter  201 , the video client  217  in the receiver  206  preferably receives the compressed stream of video images. The video client  217  preferably includes a decompressor  218  which is configured to decompress the compressed stream of video images to form a representation of the original, uncompressed stream of video images. After the compressed stream of video images is processed by the decompressor  218 , the resulting stream of video images is ready to be displayed. The decompressor  218  preferably includes a buffer  221  which is utilized with the decompression process. 
     When receiving the stored stream of video data at a later time from the recorded video device  208  in the transmitter  201 , the video play device  219  preferably receives the stored stream of video data and allows the representative stream of video images to be displayed. Before being displayed, the stored stream of video data is decompressed by the decompressor  218  in order to form a representation of the original, uncompressed stream of video images. 
     Various procedures for monitoring the video data that is received by the plurality of receivers  206  for errors is apparent to those skilled in the art. Such errors can include faulty compression, faulty decompression, missing video data, delayed video data, and the like. Further, it is also apparent to those skilled in the art to alert and notify users of the appropriate plurality of receivers  206 , the transmitter  201 , and the source device  203  when any of these errors occur. In order to avoid unnecessarily complicating the discussion of the video system  200 , specific details of the error detection and notification are not discussed. 
     In addition to the error monitoring known in the art, a novel feature of the present invention is reporting to the user when any of the requested capture, compression, transmission, decompression, and display parameters cannot be met, such that the requested quality is not being achieved. As disclosed in the provisional application, the transmitter incorporates “a means of . . . b) compressing a video image using a lossless . . . compression algorithm, d) sending the compressed frame with timecode information to each receiver . . . i) displaying video image, time code, performance, and network connection information, j) modifying video settings . . . such as brightness, contrast, hue, and so forth for the video being captured, k) sending a dropped frame indicator when a frame cannot be sent to a receiver in a time accurate manner due to capture or transmission delays” (Provisional application 60/085,818, pages 2-3); the receivers each incorporate a “means of . . . c) receiving video parameter information and a stream of compressed video frames with timecodes . . . , d) decompressing each video frame . . . and displaying it in a time accurate manner, . . . g) displaying performance, dropped frames, and network connection information, . . . k) allowing the user to specify a subset of the video frame area to be transmitted in order to increase image and motion quality” (page 3); and with receiver minimum Internet bandwidths of “1.5 Mb/sec” and “56 Kb/sec”, the “physician can at any time record a specific transmitted segment, transfer that segment at a later time, and view the segment full frame and full motion . . . ” (page 7). Thus the quality notification includes timestamps (indicating the deadline when the frame of live video must be displayed), dropped frame indicators, performance, and network information. This quality notification informs the user, for example, a physician making a medical decision based on what is being seen, whether or not the current image is actually being displayed at full medical diagnostic quality. This allows the physician to use only the medical quality portions of the transmission in the diagnosis. Further, if network congestion prevents medical quality at the current settings, the physician can change the settings (e.g. compression method, area of image, frame rate, contrast, etc.) until medical quality transmission can be achieved and maintained. If medical quality live transmission cannot be achieved in a given circumstance, e.g. over a 56K bit per second modem connection, the remote physician can still remotely direct the selection of the image (e.g. with a setting of one frame per second) and remotely start and stop the recorder, and then later download the recorded video. The actual diagnosis is then made using the lossless, medical quality recorded video. However, because the remote physician directed the image selection and recording, the recorded video will be known to have the optimal imaging. Also, the patient can receive a faster, optimal report of the study, avoid a repeat study due to an otherwise sub-optimal study, and be scheduled for surgery sooner, if necessary. This notification of the quality of the transmission also has benefits in non-medical applications. 
     In operation, the transmitter  201  acts as a server that is connected to an appropriate data network. Preferably, each of the plurality of receivers  206  individually acts as a stand-alone computer system connected to the data network. The transmitter  201  selectively enables a data stream of video images to be transmitted to an appropriate one or more of the plurality of receivers  206 . In order for a particular receiver  206  to receive the data stream of video images from the transmitter  201 , the receiver  206  logs onto the computer network  105  ( FIG. 1 ) Preferably, the computer network  105  is the Internet Protocol network. Alternatively, the computer network  105  is any appropriate data network. Typically, in the preferred embodiment, this log on is accomplished by connecting through an Internet service provider. A connection between the transmitter  201  and the particular receiver  206  is preferably established through the computer network  105  ( FIG. 1 ). The particular receiver  206  preferably communicates with the transmitter  201  over the computer network  105  and furnishes a user identification, a password, or another form of identification and verification. Once the transmitter  201  identifies the particular receiver  206  as an approved user, the transmitter  201  allows the data stream of video images to be transmitted to the particular receiver  206 . The transmitter  201  is capable of simultaneously transmitting the data stream of video images to multiple receivers  206 . 
       FIG. 8A  illustrates a flow chart showing the steps involved when transmitting a stream of video images in real-time from the transmitter  201  ( FIG. 2 ) to one or more of the plurality of receivers  206 . The steps  800 - 825  preferably occur within the transmitter  201  ( FIG. 2 ). The steps  830 - 840  preferably occur within one of the plurality of receivers  206  ( FIG. 2 ). The process of transmitting the stream of video images from the transmitter  201  to one of the plurality of receivers  206  ( FIG. 2 ) begins at the step  800 . Next, the stream of video images from the video source  203  are captured in the video image capture device  202  ( FIG. 2 ) in the step  805 . In the step  810 , the stream of video images, captured by the video image capture device  202 , is compressed by the compressor  204  ( FIG. 2 ) within the video server  212  ( FIG. 2 ). Next, in the step  815 , a connection between one of the plurality of socket handlers  214  ( FIG. 2 ) and one of the plurality of receivers  206  ( FIG. 2 ) is initiated. In the step  820 , the connection between the transmitter  201  ( FIG. 2 ) and one of the plurality of receivers  206  ( FIG. 2 ) is confirmed by the listener device  213  ( FIG. 2 ). Next, the compressed stream of video images is transmitted to an appropriate one or more of the plurality of receivers  206  ( FIG. 2 ) in the step  825 . 
     In the step  830 , the appropriate one or more of the plurality of receivers  206  ( FIG. 2 ) receives the compressed stream of video images from the transmitter  201 . Next in the step  835 , the compressed stream of video images is decompressed by the decompressor  218  ( FIG. 2 ). Finally, the stream of video images is displayed for the user by one of the plurality of receivers  206  ( FIG. 2 ) in the step  840 . 
       FIG. 8B  illustrates a flow chart showing the steps involved when transmitting a stream of pre-recorded video images from the transmitter  201  to one of the plurality of receivers  206 . The steps  850 - 870  preferably occur within the transmitter  201  ( FIG. 2 ). The steps  875 - 885  preferably occur within one of the plurality of receivers  206  ( FIG. 2 ). The process of transmitting the pre-recorded stream of video images to one of the plurality of receivers  206  ( FIG. 2 ) begins at the step  850 . Next, the stream of video images are captured in the video image capture device  202  ( FIG. 2 ) in the step  855 . In the step  860 , the stream of video images are then compressed by the compressor  204  ( FIG. 2 ) within the video server  212  ( FIG. 2 ). Next, in the step  865 , the compressed stream of video images is stored within the recorded video device  208  ( FIG. 2 ), thus forming a pre-recorded and compressed stream of video images. This pre-recorded and compressed stream of video images is capable of being stored indefinitely and transmitted to one of the plurality of receivers  206  ( FIG. 2 ) at any time. Next, the step  870  represents the steps  815 ,  820 , and  825  from  FIG. 8A , and is utilized to transmit the pre-recorded and compressed stream of video images to one of the plurality of receivers  206  ( FIG. 2 ). A resulting connection between one of the plurality of socket handlers  214  ( FIG. 2 ) and one of the plurality of receivers  206  ( FIG. 2 ) is initiated in the step  870 . Additionally in the step  870 , the connection between the transmitter  201  ( FIG. 2 ) and one of the plurality of receivers  206  ( FIG. 2 ) is confirmed by the listener device  213  ( FIG. 2 ). The pre-recorded and compressed stream of video images is also transmitted to one or more of the plurality of receivers  206  ( FIG. 2 ) in the step  870 . 
     In the step  875 , the appropriate one or more of the plurality of receivers  206  ( FIG. 2 ) receives the pre-recorded and compressed stream of video images. Next, in the step  880 , the pre-recorded and compressed stream of video images is decompressed by the decompressor  218  ( FIG. 2 ). The stream of video images is then displayed to the user by one of the plurality of receivers  206  ( FIG. 2 ) in the step  885 . 
       FIG. 3A  illustrates software code which is preferably utilized to perform compression of a stream of video data within the compressor  204  ( FIG. 2 ). This software code includes a lookup table  310  with storage locations representing illumination intensity values from 0 to 255. Each representative storage location includes a line number from 0 to 31 which is indexed to a decompression lookup table. The compression lookup table  310  allows an eight bit entry representing values from 0 to 255 to be compressed into a five bit value. When provided with an illumination intensity value, the line number stored in the corresponding location within the compression lookup table  310  is read and provided as the compressed five bit illumination intensity value. Documentation  320  is utilized to more clearly illustrate the function of each line contained within the compression lookup table  310 . If the illumination intensity value is two (on a scale of 0 to 255), the line number zero stored at the storage location corresponding to this illumination intensity value is read from the compression lookup table  310 . As can be seen from the compression lookup table  310 , any illumination intensity value between zero to four has a corresponding five bit line number of zero (on a scale of 0 to 31). In a further example, if the illumination intensity value is eighty, the line number ten stored at the storage location corresponding to this illumination intensity value is read from the compression lookup table  310 . Instead of transmitting an eight-bit value of 0 to 255 which corresponds to an illumination intensity value of a pixel, the compression lookup table  310  is utilized to compress the eight bit illumination intensity value into a corresponding five bit line number value between 0 and 31. 
     This compression process is preferably optimized to compress data representing a stream of video images which originates from the video source  203  ( FIG. 2 ) and is received by the transmitter  201  ( FIG. 2 ). In practice, this data representing the stream of video images is transmitted in terms of a stream of pixel data. A predetermined number of pixels represent each video image. Further, each pixel is represented by illumination intensity values relating to a red scale, a green scale, and a blue scale. Each of the red scale, green scale and blue scale have illumination intensity values which range from 0 to 255. For each pixel, the illumination intensity value of zero represents a fully off state, and the illumination intensity value of “255” represents a fully on state. 
     To achieve a gray scale or black and white image, each pixel within the black and white image has the same illumination intensity value for the red, green, and blue scales. In the preferred embodiment, the stream of video images are displayed as black and white images which are defined by a gray-scale having 256 shades of gray. This optimizes the compression of the video data and recognizes that full color is not necessary for good quality video images from the medical measurement devices utilized with the preferred embodiment of the present invention. Because only black and white images are utilized, the compression process preferably utilizes the intensity values for only the blue scale to represent each pixel. These illumination intensity values are modified within the compressor  204  ( FIG. 2 ) before being transmitted to one of the plurality of receivers  206  ( FIG. 2 ) or stored in the video recorder  210 , as described above. Alternatively, as will be apparent to those skilled in the art, full color is achieved by separately compressing and transmitting the red, green, and blue values. 
     In the preferred embodiment, to achieve black and white video images, the intensity values for the red and green scales are neither compressed nor transmitted. To achieve black and white video images, it is sufficient to compress and transmit the blue scale value for each pixel. At a later time after transmission and decompression of the blue scale value for each pixel, to display each pixel in terms of a gray scale, the red scale and the green scale values for a particular pixel are generated from the blue scale value. Alternate embodiments of the present invention are capable of utilizing either the green scale or the red scale value to represent each pixel. Further, alternate embodiments utilizing video images displayed in color compress and transmit the red scale, green scale, and blue scale value. 
       FIG. 3B  illustrates a lookup table  350 . This look-up table  350  shows a logical representation of the compression process according to the compression lookup table  310  shown in  FIG. 3A , for illustrative purposes only. The lookup table  350  classifies an eight bit illumination intensity value for a pixel into an appropriate level within a reduced level index representing the five bit line number. There are preferably 32 levels within this reduced level index, from 0 to 31 which are represented by the rows 0 to 31 on the left of the table  350 . Each line number corresponds with one of the levels within the reduced level index. The lookup table  350  also includes 10 columns which are represented by letters “A” through “J”. The entries within columns “A” through “I” represent the illumination intensity value for the pixel and correspond to the storage locations within the lookup table  350 . Each of the illumination intensity values are compressed into the line number of the row on which the illumination intensity value is found within the table  350 . The entries within the column “J” represent an average illumination intensity level associated with each line number, which will be discussed below in relation to the decompression lookup table. This average illumination intensity level falls within a range of a lowest and highest illumination intensity value within the particular row. 
     As a further example of the pixel data compression technique of the present invention utilizing the lookup table  350  when provided with pixel data having an illumination intensity value of 167, the line number  20  is provided as the compressed value from the compression lookup table. Any pixel having an illumination intensity value between 162 and 169 corresponds to the line number  20  in the lookup table  350 . Accordingly, for pixels having illumination intensity values between and including 162 and 169, the five bit line number  20  is provided as the compressed value, which is either stored by the recorded video device  208  or transmitted by the transmitter  201  to one or more of the receivers  206 . 
       FIG. 5A  illustrates a data structure  500  having 8 bits of storage. An identification bit  510  is preferably a leading bit within the data structure  500 . This identification bit  510  signals whether the particular data structure contains a line number representing the illumination intensity level or a repeat value representing a number of times to repeat an illumination intensity value of a prior pixel. The data structure  500  is used to carry both compressed line number values and the repeat value for compressed strings of similar pixels. 
       FIG. 5B  illustrates a data structure  525  used to transmit the repeat value, which has a specific configuration of the data structure  500  ( FIG. 5A ). To signal that this data structure  525  is transmitting a repeat value, the identification bit  510  includes a value corresponding to a logical one. The number of times to repeat is preferably stored in the seven remaining bits  530 . By storing a logical one in the identification bit  510 , the decompressor  218  ( FIG. 2 ) is instructed while decoding to repeat the line number of the previous pixel a number of times corresponding to the seven bit repeat value. In this preferred embodiment, the repeat counter value is limited to a value of 127 which is the maximum number capable of being expressed by seven bits. Alternatively, the repeat counter value can be represented by any appropriate number of bits. 
       FIG. 5C  illustrates a data structure  550  used to transmit a line number, which has a specific configuration of the data structure  500  ( FIG. 5A ). To signal that this data structure  550  is transmitting a compressed line number, representing an illumination intensity value of a pixel, the identification bit  510  includes a value corresponding to a logical zero. The data structure  550  is configured to transmit the line number which represents the illumination intensity level of the pixel. Preferably, the bits  565  and  570  are unused. The bits  575 - 595  represent the five bit line number corresponding to the illumination intensity value from the compression lookup table  310  ( FIG. 3A ). By setting the identification bit  510  to a logical zero, the decompressor  218  ( FIG. 2 ) recognizes that information held in the five bits  575 - 595  represents the line number corresponding to the illumination intensity value of a pixel in the data stream. 
       FIG. 4A  shows a flow chart which illustrates the compression process utilized by the compressor  204  ( FIG. 2 ) when compressing a stream of video data.  FIG. 4B  illustrates a representative video image  400  and a corresponding stream of pixel data  405  representing the video image  400 . The pixel data is transmitted in an order representing pixels from left to right on each horizontal line, successively, from top to bottom of the video image. As an example, pixels “C” and “D” are considered consecutive pixels within the stream of pixels  405 . 
     This compression process begins at the start step  402 , clearing the buffer  222  ( FIG. 2 ) and resetting the repeat counter value to zero. At the step  404 , an illumination intensity value representing a current pixel is received. Next, at the step  406 , a current line number from the lookup table  310  ( FIG. 3A ) is obtained for the pixel data corresponding to the current illumination intensity value for the pixel. At the step  408 , it is determined whether the current line number for the pixel data is the same as the previous line number. The previous line number is preferably stored in the buffer  222  ( FIG. 2 ). If the previous line number is not stored in the buffer  222  ( FIG. 2 ), then the current line number and the previous line number cannot be the same. If the line number is the same as the previous line number, the repeat counter value is incremented by one, at the step  410 . It is then determined whether the repeat counter value is equal to a value of 127, at the step  412 . If the repeat counter value is equal to a value of 127, then, at the step  414 , the repeat counter value is transmitted out of the compressor  204  ( FIG. 2 ) and into the buffer  223  ( FIG. 2 ) within a data structure that is similar to the data structure  525  ( FIG. 5B ). Additionally in the step  414 , the repeat counter value is reset to a value of zero after being transmitted in the data structure. If the repeat counter is not equal to the value of 127, the process then proceeds directly to the step  416 . 
     Returning back to the step  408 , if the current line number is not the same as the previous line number, then it is determined whether the repeat counter value is equal to a value of zero, in the step  420 . If it is determined at the step  420 , that the repeat counter value is not equal to the value of zero, then at the step  422 , the repeat counter value is transmitted out of the compressor  204  ( FIG. 2 ) and into the buffer  223  ( FIG. 2 ) within a data structure that is similar to the data structure  525  ( FIG. 5B ). Additionally, at the step  422 , the repeat counter value is reset to a value of zero after being transmitted in the data structure. If it is determined at the step  420 , that the repeat counter value is equal to the value of zero, or after the step  422  is completed, then the line number representing the current illumination intensity value is transmitted out of the compressor  204  ( FIG. 2 ) and into the buffer  223  ( FIG. 2 ), at the step  424 , within a data structure that is similar to the data structure  550  ( FIG. 5C ). Additionally, after the current line number is transmitted, the current line number is stored in the buffer  222  ( FIG. 2 ) as the previous line number, at the step  424 . After the step  424  is completed, the process proceeds to the step  416 . 
     At the step  416 , it is determined whether there is any additional pixel data corresponding to additional pixels. If there is additional pixel data, then the compression process loops back to the step  404  to receive and process the data representing the next pixel. If there is no additional pixel data, then the process proceeds to the step  418 . At the step  418 , it is determined whether the repeat counter value is equal to a value of zero. If the repeat counter value is equal to the value of zero, then the process proceeds to the ending step  428 . If the repeat counter value is not equal to the value of zero, then, at the step  426 , the repeat counter value is transmitted out of the compressor  204  ( FIG. 2 ) and into the buffer  223  ( FIG. 2 ) within a data structure that is similar to the data structure  525  ( FIG. 5B ). Additionally in the step  426 , the repeat counter value is reset to a value of zero after being transmitted in the data structure. After the step  426 , then the process proceeds to the ending step  428 . 
       FIG. 6  illustrates a sample uncompressed illumination intensity data stream  610  including data blocks  620 ,  622 ,  624 ,  626 ,  628 ,  630 , and  632 . Each block includes pixel data representing an illumination intensity value of a corresponding pixel in this uncompressed data stream  610 . Preferably, this illumination intensity level is the blue scale value for the particular represented pixel. For example, after the step  406  ( FIG. 4A ) of obtaining a line number value for each of the data blocks, the blocks  620 - 628  have a line number value of zero; the block  630  has a line number value of two; and the block  632  has a line number value of ten. A compressed illumination intensity data stream  640  includes data structures  650 ,  652 ,  654 , and  656 . The compressed data stream  640  represents the uncompressed data stream  610  with four data structures. Similar to the illumination intensity data structure  550  ( FIG. 5C ), the data structures  650 ,  654 , and  656  represent the illumination intensity value of the pixels associated with the data blocks  620 ,  630 , and  632 , respectively. A segment  651  of the data structure  650  contains a five bit line number having a value of zero. Similarly, the segments  655  and  657  contain five bit line numbers having values of two and ten, respectively. Similar to the repeat data structure  525  ( FIG. 5B ), the data structure  652  represents the illumination intensities of the pixels associated with the data blocks  622 ,  624 ,  626 , and  628 . A segment  653  stores the seven bit repeat counter value of four which is the number of times the line number of the prior pixel  620  is repeated. 
       FIG. 7  illustrates software code utilized to decompress a compressed stream of data. This software code includes a decompression lookup table  700  which is utilized within the decompressor  218  ( FIG. 2 ). The decompression lookup table  700  is indexed to provide an output average illumination intensity value corresponding to the received line number from the compression lookup table  310 . This decompression lookup table  700  transforms the line number representing the illumination intensity for the stream of pixels which was previously processed by the compressor  204  ( FIG. 2 ) back into a converted illumination intensity data stream having thirty-two levels of illumination intensity. Similar to the compression lookup table  310  ( FIG. 3A ), the decompression lookup table  700  utilizes thirty-two levels wherein each level represents the particular line number. For each received line number, the decompression lookup table  700  provides an output average illumination intensity value for a red scale illumination intensity value  710 , a green scale illumination intensity value  720 , and a blue scale illumination intensity value  730 . Preferably, these output average illumination intensity values are all equal, thereby providing a gray scale image. 
       FIG. 9  illustrates a flow chart which shows the preferred decompression process utilized by the decompressor  218  ( FIG. 2 ) to decompress a compressed stream of data. This decompression process begins at a start step  900  and proceeds to the step  902 . At the step  902 , a stream of compressed data which was compressed by the compressor  204  ( FIG. 2 ) and includes data representing the illumination intensity of a plurality of pixels waits to be received. The stream of compressed data contains a plurality of data structures which resemble the data structure  500  ( FIG. 5A ). At the step  902 , the next data structure in the stream of compressed data is received as a present data structure. Next, at the step  904 , the identification bit within the present data structure received by the step  902  is detected. At the step  906 , it is determined if the identification bit which was detected at the step  904  has a value of logical zero or logical one. If the identification bit has a value of logical one, then the present data structure contains a repeat counter value and is decoded at the step  912 . If the identification bit has a value of logical zero, then the present data structure contains a line number and is decoded at the step  908 . 
     At the step  912 , the repeat counter value is read from the present data structure. Recall that the repeat counter value stores the number of times to repeat the line number associated with the illumination intensity values of the prior pixel. Next, at the step  914 , a particular number of pixels corresponding to a number stored as the repeat counter value, is generated with the illumination intensity values of the prior pixel. The illumination intensity value of the prior pixel is stored in the buffer  221  ( FIG. 2 ) within the decompressor  218  ( FIG. 2 ). For example, if the repeat counter value is five, then five pixels are generated with the illumination intensity values of the prior pixel at the step  914 . 
     At the step  908 , the line number is read from the present data structure. The line number corresponds to a row within the decompression lookup table  700  ( FIG. 7 ) which includes the illumination intensity values for the pixel. Next, at the step  910 , a pixel is generated having illumination intensity values which correspond to the line number read from the step  908 . Additionally, the illumination intensity values are also stored in the buffer  221  ( FIG. 2 ) within the decompressor  218  ( FIG. 2 ). For example, if the line number within the present data structure has a value of two, then according to the decompression lookup table  700  ( FIG. 7 ), the illumination intensity values for the red, green, and blue values of the pixel are sixteen. 
     After the illumination intensity values are determined at the step  910  or the step  914 , it is determined, at the step  916 , if there are additional data structures within the compressed stream of data currently being received. If there are additional data structures, then this process loops back to the step  902  where the next data structure is received, and the process begins again. If there are not additional data structures, then this process ends at the step  918 . 
     The compression process as described above and illustrated in the flow chart shown in  FIG. 4A  is embodied and executed within the compressor  204  ( FIG. 2 ) utilizing the compression lookup table  310  ( FIG. 3A ). An uncompressed stream of data containing a plurality of eight bit illumination intensity values for a stream of pixels, each having 256 possible levels, is processed within the compressor  204  ( FIG. 2 ). Each illumination intensity value in the uncompressed stream of data is transformed by the compressor  204  ( FIG. 2 ) into a five bit line number having 32 possible levels. This line number represents the illumination intensity value having one of 32 possible levels for a corresponding pixel. In other words, each of the 32 line numbers represents a specific range of illumination intensity values. 
     By transforming the uncompressed eight bit illumination intensity value having 256 possible levels into the compressed five bit line number having 32 possible levels, some accuracy is lost in this transformation. However, because of inherent characteristics of the human eye, this accuracy loss is not noticeable when viewing a resulting image composed of pixels having illumination intensity values represented by corresponding line numbers. In order to achieve additional compression, the compressor  204  ( FIG. 2 ) also stores the number of consecutive times a prior line number is repeated as a repeat counter. The compressor  204  ( FIG. 2 ) then replaces the repeated line number(s) with a single repeat data structure which contains the repeat counter. The compressor  204  ( FIG. 2 ) produces a compressed stream of data including line number data structures and repeat data structures, as appropriate. 
     The decompression process as described in detail above and illustrated in the flow chart shown in  FIG. 9  is embodied and executed within the decompressor  218  ( FIG. 2 ) which utilizes the decompression lookup table  700  ( FIG. 7 ). The compressed stream of data is processed by the decompressor  218  ( FIG. 2 ) to transform a combination of line numbers and repeat values into a decompressed stream of illumination intensity values corresponding to the original stream of pixels. When the decompressor  218  ( FIG. 2 ) receives a particular line number, the line number is converted into appropriate illumination intensity values for the corresponding pixel in terms of the red scale, green scale, and blue scale through the decompression lookup table  700  ( FIG. 7 ). The appropriate illumination intensity values are placed in the converted stream of illumination intensity values. 
     When receiving a particular repeat command from the compressed stream of data, the decompressor  218  ( FIG. 2 ) generates an appropriate number of illumination intensity values, representing a number of pixels, in response to the repeat counter, having the same illumination intensity values as the most recent illumination intensity value in the converted stream of illumination intensity values. Each of the appropriate number of illumination intensity values is placed in the converted stream of illumination intensity values. After the decompression process, the converted stream of illumination intensity values include a plurality of illumination intensity values which closely approximates the plurality of illumination intensity values within the uncompressed stream of data. 
     In  FIG. 10 , sample data streams illustrating the compression and the decompression process of the present invention are shown. The sample data streams include an uncompressed data stream  1000 , a compressed data stream  1020 , and a decompressed data stream  1050 . The uncompressed data stream  1000  includes seven pixel data blocks  1002  through  1014  wherein each of these pixel data blocks represents the illumination intensity value of the particular pixel. The compressed data stream  1020  includes four data blocks  1022 - 1028  which are generated by the compressor  204  ( FIG. 2 ) and represent the uncompressed data stream  1000 . The decompressed data stream  1050  is generated from the decompressor  218  ( FIG. 2 ) and includes seven pixel data blocks  1052 - 1064  each representing the average illumination intensity value of the particular pixel. 
     In operation, the compressor  204  ( FIG. 2 ) receives the uncompressed data stream  1000 . The pixel data blocks  1002 ,  1004 ,  1006 ,  1008 ,  1010 ,  1012 , and  1014  store the illumination intensity values “22”, “24”, “21”, “28”, “27”, “113”, and “15”, respectively. According to the step  404  ( FIG. 4A ), the pixel data block  1002  is received. Next in the step  406  ( FIG. 4A ), the current line number for the pixel data block  1002  has a value of three, corresponding to the value stored within the storage location in the lookup table  310 , representing the illumination intensity value “22.” Since the pixel data block  1002  is the first pixel data block within the uncompressed data stream  1000 , the current line number is not the same as the previous line number, and the repeat counter value is equal to a value of zero. Accordingly, in the step  424  ( FIG. 4A ), the current line number having the value of three is transmitted into the buffer  223  ( FIG. 2 ) and is represented as a data structure  1022  in the compressed data stream  1020  which is similar to the data structure  550  ( FIG. 5C ). Further, the current line number is stored as the previous line number in the buffer  222  ( FIG. 2 ). Next, since the pixel data blocks  1004  through  1014  remain waiting to be processed, the process loops back to the step  404  ( FIG. 4A ). 
     In the step  404  ( FIG. 4A ), the pixel data block  1004  is received. Next in the step  406  ( FIG. 4A ), the current line number for the pixel data block  1004  has the value of three, corresponding to the value stored within the storage location in the lookup table  310 , representing the illumination intensity value “24.” In the step  408  ( FIG. 4A ), the current line number value is determined to be the same as the previous line number value. Next, the repeat counter value is increased from zero to one, at the step  410  ( FIG. 4A ). Since the repeat counter value is not equal to 127, the process proceeds to the step  416  ( FIG. 4A ). Next, since the pixel data blocks  1006  through  1014  remain waiting to be processed, the process loops back to the step  404  ( FIG. 4A ). 
     In the step  404  ( FIG. 4A ), the pixel data block  1006  is received. Next in the step  406  ( FIG. 4A ), the current line number for the pixel data block  1006  has the value of three, corresponding to the value stored within the storage location in the lookup table  310 , representing the illumination intensity value “21.” In the step  408  ( FIG. 4A ), the current line number value is determined to be the same as the previous line number value. Next, the repeat counter value is increased from one to two, at the step  410  ( FIG. 4A ). Since the repeat counter value is not equal to 127, the process proceeds to the step  416  ( FIG. 4A ). Next, since the pixel data blocks  1008  through  1014  remain waiting to be processed, the process loops back to the step  404  ( FIG. 4A ). 
     In the step  404  ( FIG. 4A ), the pixel data block  1008  is received. Next in the step  406  ( FIG. 4A ), the current line number for the pixel data block  1008  has the value of three, corresponding to the value stored within the storage location in the lookup table  310 , representing the illumination intensity value “28.” In the step  408  ( FIG. 4A ), the current line number value is determined to be the same as the previous line number value. Next, the repeat counter value is increased from two to three, at the step  410  ( FIG. 4A ). Since the repeat counter value is not equal to 127, the process proceeds to the step  416  ( FIG. 4A ). Next, since the pixel data blocks  1010  through  1014  remain waiting to be processed, the process loops back to the step  404  ( FIG. 4A ). 
     In the step  404  ( FIG. 4A ), the pixel data block  1010  is received. Next in the step  406  ( FIG. 4A ), the current line number for the pixel data block  1010  has the value of three, corresponding to the value stored within the storage location in the lookup table  310 , representing the illumination intensity value “27.” In the step  408  ( FIG. 4A ), the current line number value is determined to be the same as the previous line number value. Next, the repeat counter value is increased from three to four, at the step  410  ( FIG. 4A ). Since the repeat counter value is not equal to 127, the process proceeds to the step  416  ( FIG. 4A ). Next, since the pixel data blocks  1012  through  1014  remain waiting to be processed, the process loops back to the step  404  ( FIG. 4A ). 
     In the step  404  ( FIG. 4A ), the pixel data block  1012  is received. Next in the step  406  ( FIG. 4A ), the current line number for the pixel data block  1012  has a value of fourteen, corresponding to the value stored within the storage location in the lookup table  310 , representing the illumination intensity value “113.” In the step  408  ( FIG. 4A ), it is determined that the current line number value is not equal to the previous line number value. Accordingly, the process proceeds to the step  420  ( FIG. 4A ). In the step  420  ( FIG. 4A ), it is determined that the repeat counter value is not equal to zero. Accordingly, in the step  422  ( FIG. 4A ), the repeat counter value of four is transmitted into the buffer  223  ( FIG. 2 ) and is represented as a data structure  1024  in the compressed data stream  1020  which is similar to the data structure  525  ( FIG. 5B ). Next in the step  424  ( FIG. 4A ), the current line number having the value of fourteen is transmitted into the buffer  223  ( FIG. 2 ) and is represented as a data structure  1026  in the compressed data stream  1020  which is similar to the data structure  550  ( FIG. 5C ). Further, the current line number is stored as the previous line number in the buffer  222  ( FIG. 2 ). Further, the repeat counter value is reset back to the value of zero. Next, since the pixel data block  1014  remains waiting to be processed, the process loops back to the step  404 . 
     In the step  404  ( FIG. 4A ), the pixel data block  1014  is received. Next in the step  406  ( FIG. 4A ), the current line number for the pixel data block  1014  has a value of two, corresponding to the value stored within the storage location in the lookup table  310 , representing the illumination intensity value “15.” In the step  408  ( FIG. 4A ), it is determined that the current line number value is not equal to the previous line number value. Accordingly, the process proceeds to the step  420  ( FIG. 4A ). In the step  420  ( FIG. 4A ), it is determined that the repeat counter value is equal to zero. Accordingly, in the step  424  ( FIG. 4A ), the current line number having the value of two is transmitted into the buffer  223  ( FIG. 2 ) and is represented as a data structure  1028  in the compressed data stream  1020  which is similar to the data structure  550  ( FIG. 5C ). Further, the current line number is stored as the previous line number in the buffer  222  ( FIG. 2 ). Since there are no more additional pixel data blocks waiting to be processed, and the repeat counter value is equal to zero, the process ends at the ending step  428  ( FIG. 4A ). 
     The uncompressed data stream  1000  has been converted into the compressed data stream  1020 . The compressed data stream  1020  includes four bytes of data instead of the seven bytes of data included within the uncompressed data stream  1000 . 
     When the decompressor  218  ( FIG. 2 ) receives the compressed data stream  1020 , it then generates the decompressed data stream  1050 . In operation, the data structure  1022  is received as described in the step  902  ( FIG. 9 ). Next, the identification bit  1030  is determined to have a value of logical zero, in the steps  904  and  906  ( FIG. 9 ), representing that the data structure  1022  is carrying a line number. In response to this determination, the line number value of three is read from the segment  1032  in the step  908  ( FIG. 9 ). According to the lookup table  700  ( FIG. 7 ), the line number value of three corresponds to an average illumination intensity value of twenty-four. The decompressor  218  ( FIG. 2 ) then generates the block  1052  which is encoded with the average illumination intensity value of twenty four and saves the illumination intensity value of twenty-four in the buffer  221  ( FIG. 2 ), at the step  910  ( FIG. 9 ). Next, it is determined that the data block  1024  is the next data structure in the step  916  ( FIG. 9 ). Accordingly, the process loops back to the step  902  ( FIG. 9 ). 
     In the step  902  ( FIG. 9 ), the data structure  1024  is received. The identification bit  1034  is determined to have a value of logical one, in the steps  904  and  906  ( FIG. 9 ), representing that the data structure  1024  is carrying a repeat counter value. In response to this determination, a repeat counter value of four is read from the segment  1036 , in the step  912  ( FIG. 9 ). The decompressor  218  ( FIG. 2 ) then reads the average illumination intensity value stored in the buffer  221  ( FIG. 2 ) and generates four blocks  1054 ,  1056 ,  1058 , and  1060  each having the average illumination intensity values of twenty-four. Next, it is determined that the data structure  1026  is the next data structure in the step  916  ( FIG. 9 ). Accordingly, the process loops back to the step  902  ( FIG. 9 ). 
     In the step  902  ( FIG. 9 ), the data structure  1026  is received. The identification bit  1038  is determined to have a value of logical zero, in the steps  904  and  906  ( FIG. 9 ), representing that the data structure  1026  is carrying a line number. In response to this determination, the line number of fourteen is read from the segment  1040 , in the step  908  ( FIG. 9 ). According to the lookup table  700  ( FIG. 7 ), the line number value of fourteen corresponds to an average illumination intensity value of “115.” The decompressor  218  ( FIG. 2 ) then generates the block  1062  which is encoded with the average illumination intensity value of “115” and saves the illumination intensity value of “115” in the buffer  221  ( FIG. 2 ), at the step  910  ( FIG. 9 ). Next, it is determined that the data block  1028  is the next data structure in the step  916  ( FIG. 9 ). Accordingly, the process loops back to the step  902  ( FIG. 9 ). 
     In the step  902  ( FIG. 9 ), the data structure  1028  is received. The identification bit  1042  is determined to have a value of logical zero, in the steps  904  and  906  ( FIG. 9 ), representing that the data structure  1028  is carrying a line number. In response to this determination, the line number of two is read from the segment  1044 , in the step  908  ( FIG. 9 ). According to the lookup table  700  ( FIG. 7 ), the line number value of two corresponds to an average illumination intensity value of “16.” The decompressor  218  ( FIG. 2 ) then generates the block  1064  which is encoded with the illumination intensity value of sixteen and saves the illumination intensity value of sixteen in the buffer  221  ( FIG. 2 ), at the step  910  ( FIG. 9 ). Next, in the step  916  ( FIG. 9 ), it is determined that there is no additional data structure. Accordingly, the process ends at the ending step  918  ( FIG. 9 ). 
     In the preferred embodiment, only the blue scale illumination intensity relating to each pixel is compressed, transmitted, and finally decompressed. Because the preferred embodiment utilizes black and white video images, the decoding table  700  decodes the average illumination value for the blue scale and automatically sets the same illumination intensity for both the red and green scales. 
     The above example of the preferred embodiment merely illustrates a sample operation of the present invention utilizing black and white video images. It is well within the scope of the present invention to utilize color video images. 
     The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of the principles of construction and operation of the invention. Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It will be apparent to those skilled in the art that modifications may be made in the embodiment chosen for illustration without departing from the spirit and scope of the invention.