Patent Publication Number: US-2022215514-A1

Title: Video processing apparatus, video processing method, and recording medium

Description:
BACKGROUND 
     The present invention relates to a video processing apparatus, a video processing method, and a video processing program. 
     WO 2019/003285 discloses an image processing device, an image processing method, and a program by which changes due to biological factors can be viewed. In WO 2019/003285, involuntary eye movement is not considered. 
     SUMMARY 
     A video processing apparatus of the disclosure technology comprise: an acquisition unit configured to acquire subject eye video data; an elimination unit configured to eliminate positional offset resulting from involuntary eye movement from the subject eye video data on the basis of the subject eye video data acquired by the acquisition unit; an emphasis unit configured to perform emphasis on the subject eye video data that was subjected to the elimination performed by the elimination unit; and an output unit configured to output the subject eye video data that was subjected to the emphasis by the emphasis unit. 
     In video processing method of the disclosure technology, a processor executes: an acquisition process of acquiring subject eye video data; an elimination process of eliminating positional offset resulting from involuntary eye movement from the subject eye video data on the basis of the subject eye video data acquired by the acquisition process; an emphasis process of performing emphasis on the subject eye video data that was subjected to the elimination performed by the elimination process; and an output process of outputting the subject eye video data that was subjected to the emphasis by the emphasis process. 
     A video processing program of the disclosure technology causes a processor to execute: an acquisition process of acquiring subject eye video data; an elimination process of eliminating positional offset resulting from involuntary eye movement from the subject eye video data on the basis of the subject eye video data acquired by the acquisition process; an emphasis process of performing emphasis on the subject eye video data that was subjected to the elimination performed by the elimination process; and an output process of outputting the subject eye video data that was subjected to the emphasis by the emphasis process. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a descriptive view showing an example of involuntary eye movement elimination and video magnification (video emphasis). 
         FIG. 2  is a system configuration drawing showing an example of an ophthalmic system. 
         FIG. 3  is a block diagram for illustrating a hardware configuration example of each of a computer. 
         FIG. 4  is a block diagram showing a mechanical configuration example of a video processing apparatus. 
         FIG. 5  is a flowchart showing an example of image processing steps performed by the video processing apparatus. 
         FIG. 6A  is a block diagram showing a detailed functional configuration example of the elimination unit. 
         FIG. 6B  is a block diagram showing a detailed functional configuration example of the emphasis unit. 
         FIG. 7  is a descriptive drawing showing the fundus video data subjected to video emphasis by the emphasis unit. 
         FIG. 8  is a descriptive drawing showing a display example 1 of the fundus video data. 
         FIG. 9  is a descriptive drawing showing a display example 2 of the fundus video data. 
         FIG. 10  is a descriptive drawing showing a display example 3 of the fundus video data. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     &lt;Example of Involuntary Eye Movement Elimination and Video Emphasis&gt; 
       FIG. 1  is a descriptive view showing an example of involuntary eye movement elimination and video magnification (video emphasis). T is the time axis. The arrow of the time axis T is the time axis direction, or in other words, the direction in which time progresses. (A) shows fundus video data  100 . The fundus video data  100  is video data attained by capturing a region including a macula  101 , an optic disc  102 , and blood vessels  103  of the fundus of a subject. The fundus video data  100  includes fundus image frames F 1  to F 4  in chronological order, for example. The smaller the suffix number is, the earlier the frame is. If not distinguishing between the fundus image frames F 1  to F 4 , the fundus image frames are referred to as the fundus image frames F. For ease of description, only fundus image frames up to the fundus image frame F 4  are included here, but there may be fundus image frames F beyond the fundus image frame F 4 . 
     The fundus image frames F 1  to F 4  include, as image data, the macula  101 , the optic disc  102 , and the blood vessels  103 . Tissue other than the macula  101 , the optic disc  102 , and the blood vessels  103  are omitted from the depiction. The fundus image frame F 1  serves as a reference frame for position-matching the fundus image frames F 2  to F 4 . The fundus image frames F 2  to F 4  depict the macula  101 , the optic disc  102 , and the blood vessels  103  of the fundus image frame F 1  with dotted lines. 
     The fundus is imaged in a state where the imaging device is fixed in place, and thus, the macula  101 , the optic disc  102 , and the blood vessels  103  of the fundus image frames F 2  to F 4  are offset from the positions of the macula  101 , the optic disc  102 , and the blood vessels  103  of the fundus image frame F 1  due to involuntary eye movement. 
     Involuntary eye movement is movement of the eye, referred to as a saccade, in which the gaze repeatedly shifts rapidly (approximately 100-500 instances per second) over short periods of time (approximately 20-80 ms). Depending on the dynamic characteristics of the involuntary eye movement, involuntary eye movement can be classified into the following types: microsaccades in which the eye movement is relatively large and fast; drift, in which the movement is large and slow; and tremors, in which the movement is small and high frequency. 
     Also, the amount of blood flowing through the blood vessels  103  increases or decreases depending on the heartbeat. For example, the amount of blood flowing through the blood vessels  103  is greater in the fundus image frames F 2  and F 4  compared to the fundus image frames F 1  and F 3 . Thus, the blood vessels  103  are wider and darker in color in the fundus image frames F 2  and F 4  than in the fundus image frames F 1  and F 3 . 
     In (A), the blood vessels  103  in the fundus image frame F 1  are the lightest in color, and the blood vessels  103  in the fundus image frames F 2  and F 4  are the darkest in color. Also, the color of the blood vessels  103  in the fundus image frame F 3  is darker than the blood vessels  103  of the fundus image frame F 1  but lighter than the blood vessels  103  of the fundus image frames F 2  and F 4 . 
     Video data V is the fundus video data  100  from playing back the fundus image frames F 1  to F 4  in the time direction. The video data V is the fundus video data  100  at the display timing of the fundus image frame F 4 , and the macula  101 , the optic disc  102 , and the blood vessels  103  of the previous fundus image frames F 1  to F 3  are visible as residual images. Thus, a physician who is the user would have difficulty knowing whether the width and color of the blood vessels  103  is changing due to the heartbeat or involuntary eye movement. That is, in reality, it is difficult to distinguish between changes in the width and color of the blood vessels  103  and positional shifts and color changes in the blood vessels between frames resulting from involuntary eye movement. 
     (B) shows fundus video data  110  in which involuntary eye movement has been eliminated from the fundus video data  100  of (A). The fundus video data  110  includes fundus image frames G 1  to G 4  in chronological order. The fundus image frames G 1  to G 4  are frames in which involuntary eye movement was eliminated from the fundus image frames F 1  to F 4 , respectively, through image processing. If not distinguishing between the fundus image frames G 1  to G 4 , the fundus image frames are referred to as the fundus image frames G. 
     By correcting for positional offset between frames resulting from involuntary eye movement, the involuntary eye movement is eliminated, and thus, the macula  101 , the optic disc  102 , and the blood vessels  103  of the fundus image frames G 2  to G 4  are, respectively, displayed in the same positions as the macula  101 , the optic disc  102 , and the blood vessels  103  of the fundus image frame F 1 , which are indicated with the dotted lines in the fundus image frames F 2  to F 4 . On the other hand, movement and color changes in the blood vessels  103  resulting from the heartbeat are not eliminated. Thus, confusion between involuntary eye movement and pulsation and color changes in specific tissue such as the blood vessels  103  is mitigated, and the user such as a physician can observe the pulsation and color changes of the specific tissue without the influence of the involuntary eye movement. 
     (C) shows fundus video data  120  generated by performing processing in which the blood vessels  103  are subjected to video emphasis as specific tissue within the fundus video data  110  of (B), with changes in the width and color of the blood vessels  103  being displayed with emphasis. The fundus video data  120  includes fundus image frames H 1  to H 4  in chronological order. The fundus image frames H 1  to H 4  are frames generated by performing video emphasis on the fundus image frames G 1  to G 4 , respectively, through image processing. If not distinguishing between the fundus image frames H 1  to H 4 , the fundus image frames are referred to as the fundus image frames H. Video emphasis is a technique by which minute changes in movement that are one pixel or less in the footage and small changes in color and movement are displayed with emphasis. By performing video emphasis on the fundus video, it is possible to display with emphasis changes in the width (movement) and color of the blood vessels resulting from the heartbeat. As a result, the user such as a physician can view with ease the color changes in the blood vessel  103  resulting from the heartbeat. Below, the mechanism by which the involuntary eye movement is eliminated will be described. 
     &lt;Ophthalmic System&gt; 
       FIG. 2  is a system configuration drawing showing an example of an ophthalmic system. In the ophthalmic system  200 , a slit lamp  202  (slit lamp microscope) and a surgical microscope  203  constituting an ophthalmic apparatus  201 , a management server  204 , and a terminal  205  are connected in a manner enabling communication therebetween via a network  206  such as a LAN (local area network), a WAN (wide area network), or the internet. The slit lamp  202  is a microscope in which a subject eye is illuminated with slit light, and an illuminated cross section of the subject eye is imaged and observed from the side. The surgical microscope  203  is a microscope specialized for surgery. Both the slit lamp  202  and the surgical microscope  203  can generate, transmit, store, and display the fundus video data  100 ,  110 , and  120  as subject eye video data. As long as the ophthalmic apparatus  201  can image the subject eye of the patient, the ophthalmic apparatus  201  may be a fundus camera, a scanning laser ophthalmoscope (SLO), or an optical coherence tomography (OCT) device. 
     The management server  204  acquires and stores fundus video data from the ophthalmic apparatus  201 , or transmits the fundus video data to the ophthalmic apparatus  201  or the terminal  205 . The terminal  205  receives and plays back the fundus video data from the ophthalmic apparatus  201  or the management server  204 , or transmits the fundus video data  100 ,  110 , and  120  to the ophthalmic apparatus  201  or the management server  204 . 
     At least one of the ophthalmic apparatus  201 , the management server  204 , and the terminal  205  can execute the involuntary eye movement elimination described in  FIG. 1 , and at least one of the ophthalmic apparatus  201 , the management server  204 , and the terminal  205  can execute the video emphasis described in  FIG. 1 . That is, the involuntary eye movement elimination and the video emphasis may be executed by the same device or by different devices. 
     &lt;Computer Hardware Configuration Example&gt; 
     Next, a computer hardware configuration example will be described. A computer is a collective term for the ophthalmic apparatus  201 , the management server  204 , and the terminal  205  shown in  FIG. 2 . If the computer is the ophthalmic apparatus  201 , then a light source, an optical system, and a sensor (not shown) are included. 
     &lt;Hardware Configuration Example of Computer&gt; 
       FIG. 3  is a block diagram for illustrating a hardware configuration example of each of a computer. A computer  300  includes a processor  301 , a storage device  302 , an input device  303 , an output device  304 , and a communication interface (communication IF)  305 . The processor  301 , the storage device  302 , the input device  303 , the output device  304 , and the communication IF  305  are coupled to one another through a bus  306 . The processor  301  is configured to control the computer  300 . The storage device  302  serves as a work area for the processor  301 . The storage device  302  is also a non-transitory or transitory recording medium configured to store various programs and various kinds of data. Examples of the storage device  302  include a read only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), and a flash memory. The input device  303  is configured to input data. Examples of the input device  303  include a keyboard, a mouse, a touch panel, a numeric keypad, and a scanner. The output device  304  is configured to output data. Examples of the output device  304  include a display, and a printer. The communication IF  305  is coupled to the network  206 , and is configured to transmit and receive data. 
     &lt;Functional Configuration Example of Video Processing Device&gt; 
       FIG. 4  is a block diagram showing a mechanical configuration example of a video processing apparatus, and  FIG. 5  is a flowchart showing an example of image processing steps performed by the video processing apparatus. In  FIG. 4 , the video processing apparatus  400  has an acquisition unit  401 , an elimination unit  402 , an emphasis unit  403 , and an output unit. The video processing apparatus  400  has at least one of the elimination unit  402  and the emphasis unit  403  in a computer  300 . The video processing apparatus  400  is constituted of one computer  300 , or a plurality of linked computers  300 . 
     The acquisition unit  401 , the elimination unit  402 , the emphasis unit  403 , and the output unit are specifically realized by a processor  301  executing programs stored in a storage device  302  shown in  FIG. 3 , for example. 
     The acquisition unit  401  acquires the fundus video data  100  from the storage device  302  in the video processing apparatus  400  or from another computer  300  outside of the video processing apparatus  400  (step S 501 ). The elimination unit  402  eliminates involuntary eye movement from the fundus video data  100  on the basis of the fundus video data  100  acquired by the acquisition unit  401 , or in other words, corrects the positional offset in the fundus region between frames resulting from involuntary eye movement to eliminate the effect of involuntary eye movement from the video data (step S 502 ). 
     The emphasis unit  403  executes emphasis processing through VM for the fundus video data  110  in which the effect of involuntary eye movement was eliminated by the elimination unit  402  (step S 503 ). Specifically, for example, the emphasis unit  403  emphasizes specific frequency components in the time direction. The emphasis unit  403  may emphasize the entirety of each of the fundus image frames F of the fundus video data  100 , or may emphasize regions including specific tissue such as the macula  101 , the optic disc  102 , the blood vessels  103 , or the like. 
     The output unit  404  outputs the fundus video data  120  in which the specific tissue was emphasized by the emphasis unit  403  (step S 504 ). Specifically, the output unit  404  displays the fundus video data  120  in the display device of the video processing apparatus  400 , or transmits the fundus video data  120  from the video processing apparatus  400  to another computer  300 , for example. 
       FIG. 6A  is a block diagram showing a detailed functional configuration example of the elimination unit  402 . The elimination unit  402  includes a first elimination unit  601 , a second elimination unit  602 , and a third elimination unit  603 . First, the first elimination unit  601  will be described. 
     The first elimination unit  601  eliminates involuntary eye movement in order for the emphasis unit  403  to emphasize the movement and color change of specific tissue such as the blood vessels  103 . Specifically, the first elimination unit  601  is also an involuntary eye movement elimination unit, for example. As described in  FIG. 1 , the first elimination unit  601  sets the fundus image frame F 1  as the reference frame, and executes position-matching with the other fundus image frames F 2  to F 4  as comparison frames. Here, the reference frame was set as the oldest fundus image frame F 1  among the fundus image frames F 1 , but the reference frame may be set to any of the fundus image frames F 2  to F 4 . Setting the oldest fundus image frame F 1  as the reference frame would improve real-time processing. 
     As a result of the positional offset of the fundus due to involuntary eye movement being corrected through position-matching of the frames, the effect of involuntary eye movement is eliminated from the corrected video data, and the blood vessels  103 , the optic disc  102 , and the macula  101  are in the same position for all of the frames. Thus, the emphasis unit  403 , to be described later, emphasizes the change in width and color of the blood vessels  103  resulting from the heartbeat. 
     Position-matching between the reference frame and the comparison frames is executed through non-rigid position-matching using an affine transformation matrix including transformation through translation, rotation, and expansion/contraction. Also, the elimination unit  402  may use an algorithm such as scale-invariant feature transform (SIFT) or speeded up robust features (SURF), which is a speeded up version of SIFT. 
     Additionally, the first elimination unit  601  may use, as the evaluation function, the sum of squared differences (SSD) for pixel values at the same position, the sum of absolute differences (SAD) for pixel values at the same position, mutual information, or cross-correlation in order to perform position-matching between the reference frame and comparison frames. If mutual information or cross-correlation is used, for example, then the greater than 0 the correlation value is, the more similar the reference frame and the comparison frames are, and the less the correlation value is, the less similar the reference frame and the comparison frames are. 
     Thus, by executing position-matching between the reference frame and the comparison frames, the positions of the macula  101 , the optic disc  102 , and the blood vessels  103  of the fundus image frames F 2  to F 4  that are the comparison frames of  FIG. 1  are made to match the respective positions of the macula  101 , the optic disc  102 , and the blood vessels  103  of the reference frame (fundus image frame F 1 ) depicted with the dotted lines. As a result, the positions of the macula  101 , the optic disc  102 , and the blood vessels  103  match in the fundus image frames F 1  to F 4 , and therefore, involuntary eye movement is eliminated from the fundus video data  100 . 
     Also, the first elimination unit  601  may eliminate, from the fundus video data  100 , comparison frames in which the above-mentioned correlation value is less than or equal to a threshold. A comparison frame with a correlation value less than or equal to the threshold has a low degree of similarity to the reference frame, and thus, can be said to be frames showing microsaccades, which are a relatively large and fast eye movements, microsaccades being one of the dynamic characteristics of the involuntary eye movement. Thus, by eliminating comparison frames with a correlation value less than or equal to the threshold from the fundus video data  100 , the first elimination unit  601  can generate the fundus video data  110  in which microsaccades are not displayed. 
     Next, the second elimination unit  602  will be described. The second elimination unit  602  executes elimination processing for the emphasis unit  403  to emphasize only the color change, among the movement and color change, of specific tissue such as the blood vessels  103 . Specifically, the second elimination unit  602  has a separation unit  621 , a time filtering unit  622 , a phase noise elimination unit  623 , an attenuation unit  624 , and a reconstruction unit  625 , for example. 
     The separation unit  621  uses a known filtering process such as complex steerable pyramids to separate the fundus image frames G into a high frequency component hpr, a low frequency component lpr, and a plurality of orthogonal components every time a fundus image frame G that was subjected to involuntary eye movement elimination by the first elimination unit  601  is inputted. 
     That is, the separation unit  621  separates localized wave amplitudes (high frequency component hpr, low frequency component lpr) from the phases (plurality of orthogonal components) of the wave. The separation unit  621  outputs the high frequency component hpr and the low frequency component lpr to the reconstruction unit  625  and outputs the plurality of orthogonal components to the time filtering unit  622 . 
     The time filtering unit  622  independently filters, by time, the phases (plurality of orthogonal components) of the fundus image frames F by position, direction, and scale. The phase noise elimination unit  623  applies spatial smoothing that is weighted by amplitude to increase the S/N ratio of the phases. 
     The attenuation unit  624  attenuates the phases that were band-passed by time by the time filtering unit  622 . As a result, movement of specific tissue (e.g., the blood vessels  103 ) due to errors (corresponding to heartbeats) occurring due to position-matching by the first elimination unit  601  is suppressed. The reconstruction unit  625  reconstructs the fundus image frames G using the output from the attenuation unit  624 , the high frequency component hpr, and the low frequency component lpr. Thus, the reconstructed fundus image frames G are image frames in which the movement of specific tissue is suppressed. 
     Next, the third elimination unit  603  will be described. The third elimination unit  603  executes elimination processing for the emphasis unit  403  to emphasize only the movement, among the movement and color change, of specific tissue such as the blood vessels  103 . Specifically, for example, the third elimination unit  603  accumulates the fundus image frames G that were subjected to involuntary eye movement elimination by the first elimination unit  601 , and determines whether the difference in color density in specific tissue (e.g., the blood vessels  103 ) between two consecutive fundus image frames G is greater than or equal to a threshold. If the difference is greater than or equal to the threshold, then the fundus image frame G with the lighter color density for the specific tissue (e.g., the blood vessels  103 ), among the two consecutive fundus image frames G, is eliminated. 
     In the case of the fundus image frames G 1  to G 4  shown in (B) of  FIG. 1 , for example, if the difference in color density of the blood vessels  103  between the fundus image frames G 1  and G 2  is greater than or equal to the threshold, the third elimination unit  603  eliminates the fundus image frame G 1 , which has the lighter color density for the blood vessels  103 . If the difference in color density of the blood vessels  103  between the fundus image frames G 2  and G 3  and between the fundus image frames G 3  and G 4  is not greater than or equal to the threshold, the fundus image frames G 2  and G 3  are not eliminated. 
       FIG. 6B  is a block diagram showing a detailed functional configuration example of the emphasis unit  403 . The emphasis unit  403  has a spatial separation unit  701 , a time filtering unit  702 , amplification units  703 - 1 ,  703 - 2  . . .  703 - n  (n being an integer of 2 or greater), addition units  704 - 1 ,  704 - 2  . . .  704 - n , and a reconstruction unit  705 . If not distinguishing between the amplification units  703 - 1 ,  703 - 2  . . .  703 - n , these are referred to simply as the amplification units  703 . If not distinguishing between the addition units  704 - 1 ,  704 - 2  . . .  704 - n , these are referred to simply as the addition units  704 . First, the spatial separation unit  701  will be described. 
     The spatial separation unit  701  separates the fundus image frames G into a plurality of different spatial frequency bands (band  1 , band  2  . . . band n) every time a fundus image frame G subjected to involuntary eye movement elimination by the elimination unit  402  is inputted. A known filtering process such as bandpass filters and complex steerable pyramids can be used. The spatial frequency increases in the order of the band  1 , the band  2  . . . the band n. The image data g 1  allocated to the band  1 , the image data g 2  allocated to the band  2  . . . and the image data gn allocated to the band n by the spatial separation unit  701  are outputted to the time filtering unit  702 . 
     Next, the time filtering unit  702  uses a known filtering process such as a second-order infinite impulse response (IIR) filter to extract 60-80 kHz frequency components, which are frequencies at which the human heart beats, from the image data g 1 , g 2  . . . gn. 
     The image data g 1  that has passed through the time filtering unit  702  is amplified on the basis of an emphasis coefficient set by the amplification unit  703 - 1 . The emphasis coefficient is set to a factor of 10, for example, and the amplitude of the image data g 1  is amplified by 10 times. The image data g 1  that has passed through the amplification unit  703 - 1  is added by the addition unit  704 - 1  to the image data g 1  outputted from the spatial separation unit  701  and outputted to the reconstruction unit  705 . Similarly, the image data g 2  is also outputted to the reconstruction unit  705  via the amplification unit  703 - 2  and the addition unit  704 - 2 . The image data gn is also outputted to the reconstruction unit  705  via the amplification unit  703 - n  and the addition unit  704 - n.    
     The emphasis coefficient of the amplification unit  703  is the same for the entirety of the fundus image frame G subjected to involuntary eye movement elimination by the elimination unit  402 , but the emphasis coefficient may be set spatially (for each pixel). Specifically, an emphasis region such as the optic disc  102  or the blood vessels  103  is extracted by image processing employing artificial intelligence or the like or by user instruction, and the emphasis coefficient of the pixels of the extracted emphasis region is set to a differing value than other regions in the fundus image frame G. As a result, video emphasis is performed only on the emphasis regions of the fundus image frame G. 
     The reconstruction unit  705  uses the image data h 1 , h 2  . . . hn outputted from the addition units  704 - 1 ,  704 - 2  . . .  704 - n  to reconstruct the fundus image frames G. In this manner, the reconstructed fundus image frames G are the image frames H 1  to H 4  in which periodic fluctuations resulting from the heartbeat are emphasized for specific tissue. 
     The user (ophthalmologist or the like) can select among a plurality of video emphasis modes via an input device  303 . At least the following video emphasis modes are made available: normal mode in which both movement and color changes are emphasized; color emphasis mode in which only color change is emphasized; and movement emphasis mode in which only movement is emphasized. If normal mode is selected, the fundus video data  100  is subjected by the first elimination unit  601  of the elimination unit  402  to correction of positional offset among frames resulting from involuntary eye movement, and subjected to video emphasis by the emphasis unit  403 . 
     If color mode is selected, the fundus video data  100  is subjected by the first elimination unit  601  of the elimination unit  402  to correction of positional offset among frames resulting from involuntary eye movement, and then movement of specific tissue is eliminated by the second elimination unit  602 . Then, video emphasis is performed by the emphasis unit  403 . 
     If movement emphasis mode is selected, the fundus video data  100  is subjected by the first elimination unit  601  of the elimination unit  402  to correction of positional offset among frames resulting from involuntary eye movement, and then color change is eliminated by the third elimination unit  603 . Then, video emphasis is performed by the emphasis unit  403 . 
     &lt;Fundus Video Data  120  Subjected to Video Emphasis&gt; 
       FIG. 7  is a descriptive drawing showing the fundus video data  120  subjected to video emphasis by the emphasis unit  403 . In  FIG. 7 , periodic fluctuation resulting from the heartbeat is emphasized for specific tissue such as the blood vessels  103 . Color change of the blood vessels  103  is observed as a darkening of the blood vessel  103  when blood is sent therethrough and a lightening of the blood vessel  103  thereafter, for example. The movement of the blood vessels  103  involves expansion when blood is pumped therethrough (increased width of the blood vessels  103 ), and then contraction of the blood vessels  103 . Movement and color change tend to be greater for veins than arteries. 
     (A) shows the fundus video data  120  generated by performing video emphasis on the fundus video data  110  subjected to involuntary eye movement elimination by the first elimination unit  601 . In this fundus video data  120 , both movement and color changes of the blood vessels  103  are emphasized. 
     (B) shows the fundus video data  120  generated by performing video emphasis on the fundus video data  110  subjected to involuntary eye movement elimination by the first elimination unit  601  and movement elimination for specific tissue by the second elimination unit  602 . In this fundus video data  120 , the specific tissue is the blood vessels  103 , and only the color change of the blood vessels  103  is emphasized. 
     (C) shows the fundus video data  120  generated by performing video emphasis on the fundus video data  110  subjected to involuntary eye movement elimination by the first elimination unit  601  and color change elimination by the third elimination unit  603 . In this fundus video data  120 , the color change is eliminated (the fundus image frame G 1  with the lighter color density is eliminated), and only the movement of the blood vessels  103  (change in width of the blood vessels) is emphasized. 
     &lt;Display Examples of Fundus Video Data&gt; 
     Next, display examples of the fundus video data  100 ,  110 , and  120  will be described with reference to  FIGS. 8 to 10 . The computer  300  may display the fundus video data  110  and  120  in real time during examination, treatment, and surgery, or may read the fundus video data  110  and  120  stored in the storage device  302  and play back the fundus video data, for example. The fundus video data  100  not subjected to involuntary eye movement elimination may be 2-dimensional video data or 3-dimensional video data. 
       FIG. 8  is a descriptive drawing showing a display example 1 of the fundus video data. A display screen  800  includes a video data display region  801 , a patient information display region  802 , and a parameter information display region  803 . The video data display region  801  displays the fundus video data  100  and  120 . Thus, the user can view while comparing the fundus video data  100 , which is live footage, and the fundus video data  120 , which was subjected to involuntary eye movement elimination and video emphasis. 
     The patient information display region  802  displays patient information. The patient information is information identifying the patient such as the personal name, the address, and the like. The patient is a person having the subject eye being imaged as the fundus video data  100 . 
     The parameter information display region  803  displays parameter information. The parameter information includes an emphasis parameter and biological monitoring information, for example. The emphasis parameter is a parameter indicating the frequency domain to be emphasized by video emphasis by the emphasis unit  403  and the degree of emphasis. The biological monitoring information is information from monitoring the body of the patient such as the pulse of the patient. 
       FIG. 9  is a descriptive drawing showing a display example 2 of the fundus video data. A display screen  900  includes a first video data display region  901 , a second video data display region  902 , the patient information display region  802 , and the parameter information display region  803 . The first video data display region  901  displays the fundus video data  100  prior to involuntary eye movement elimination. The first video data display region  901  is the main screen and is larger than the second video data display region  902 . The second video data display region  902  displays the fundus video data  120  after involuntary eye movement elimination and video emphasis. The second video data display region  902  is a subscreen and is smaller than the first video data display region  901 . As a result, the user can focus on the first video data display region  901  while viewing the second video data display region  902  as necessary. 
       FIG. 10  is a descriptive drawing showing a display example 3 of the fundus video data. The display screen  1000  has the first video data display region  901  that displays the fundus video data  100  prior to involuntary eye movement elimination and the second video data display region  902  that displays the fundus video data  120  after involuntary eye movement elimination and video emphasis, for example. The second video data display region  902  is displayed so as to be superimposed on the upper right corner of the first video data display region  901 . As a result, the user can focus on the first video data display region  901  while viewing the second video data display region  902  as necessary. 
     If a changeover switch such as a foot switch is provided to the ophthalmic apparatus  201 , then the display content of the video data display region  801  and the second video data display region  902  may be switched from the fundus video data  120  to the fundus video data  110  or from the fundus video data  110  to the fundus video data  120  according to the changeover switch being switched ON or OFF. As a result, it is possible to see the difference before and after the video emphasis. 
     Also, in  FIGS. 9 and 10 , switching may be performed according to the switching of the changeover switch ON or OFF such that the fundus video data  120  is displayed in the first video data display region  901  and the fundus video data  100  is displayed in the second video data display region  902 . As a result, it is possible for the user to view the fundus video data  120  in the larger main screen. 
     Also, if viewing the fundus video data through an eyepiece of the ophthalmic apparatus  201 , the fundus video data  110  and  120  may respectively be viewable through either one of the lenses of the eyepiece for each eye. For example, in the case of  FIG. 10 , the fundus video data  100  is viewed with the right eye and the fundus video data  100  and  120  is viewed with the left eye. 
     Also, the display screens  800 ,  900 , and  1000  of  FIGS. 8 to 10  may display a mode switching button for switching between video emphasis modes, enabling the user to select between the normal mode in which both movement and color changes are emphasized, color emphasis mode in which only color change is emphasized, and movement emphasis mode in which only movement is emphasized. The fundus video data  120  in the selected video emphasis mode is displayed in the video data display region  801  or the second video data display region  902 . 
     Also, the display screens  800 ,  900 , and  1000  of  FIGS. 8 to 10  display live video (fundus video data  100  prior to involuntary eye movement elimination), but may display the fundus video data  120  after involuntary eye movement elimination. 
     In this manner, it is possible to improve flexibility for the user in viewing the video data before and after video emphasis after being subjected to involuntary eye movement elimination. 
     The present invention is not limited to the content above, and the content above may be freely combined. Also, other aspects considered to be within the scope of the technical concept of the present invention are included in the scope of the present invention. 
     EXPLANATION OF REFERENCES 
     
         
           100 , 110 , 120  fundus video data,  101  macula,  102  optic disc,  103  blood vessel,  200  ophthalmic system,  201  ophthalmic apparatus,  204  management server,  205  terminal,  400  video processing apparatus,  401  acquisition unit,  402  elimination unit,  403  emphasis unit,  404  output unit,  601  first elimination unit,  602  second elimination unit,  603  third elimination unit,  621  separation unit,  622  time filtering unit,  623  phase noise elimination unit,  624  attenuation unit,  625  reconstruction unit, F,G,H fundus image frame