JP4791570B2 - Moving image correction coefficient calculation device - Google Patents

Description

  The present invention relates to a moving image correction coefficient calculation apparatus, a moving image correction coefficient calculation method, a moving image correction coefficient calculation program, and a calculated correction coefficient that are applied to a moving image frame. In particular, a moving image correction coefficient calculation apparatus, a moving image correction apparatus, a moving image correction coefficient calculation method, and a moving image capable of realizing a good balance between improvement in image quality and reduction in calculation amount The present invention relates to an image correction coefficient calculation program.

  Conventionally, various corrections such as gamma correction, color balance correction, and saturation correction have been performed on moving images acquired by a video camera or the like for the purpose of improving image quality. This correction is normally performed for each frame of the moving image. However, since the calculation amount is enormous, a method capable of reducing the calculation amount has been proposed.

  For example, Patent Document 1 discloses a moving image in which a correction coefficient is calculated only when a scene change in which an image changes greatly is detected, and the calculation amount is reduced by using the correction coefficient until the next scene change is detected. A processing device is disclosed.

  Patent Document 2 discloses a video processing device that calculates a correction coefficient when there is a scene change, or when the number of moving image frames is counted and the counted value exceeds a predetermined threshold. ing.

JP 2002-77723 A JP 2002-262303 A

  However, in the prior arts of Patent Document 1 and Patent Document 2 described above, the same correction coefficient is used until a scene change is detected or until the number of frames exceeds a certain value. There was a problem that I could not hope.

  Therefore, in order to improve the image quality, in the prior art of Patent Document 2, the predetermined threshold value compared with the value obtained by counting the number of frames may be reduced, and the correction coefficient may be calculated at a shorter time interval. There has been a problem that the amount of calculation for calculating the correction coefficient increases.

  The present invention has been made to solve the above-described problems caused by the prior art, and a moving image correction coefficient calculating device and a moving image correcting device capable of realizing a good balance between improvement in image quality and reduction in calculation amount. Another object is to provide a moving image correction coefficient calculation method and a moving image correction coefficient calculation program.

  In order to solve the above-described problems and achieve the object, the present invention is a moving image correction coefficient calculation apparatus for calculating a correction coefficient applied to a moving image frame, and includes a moving image correction coefficient calculation device. Temporary correction coefficient calculation means for calculating a temporary correction coefficient applied to a frame extracted based on the first reference, and temporary correction coefficient for storing the temporary correction coefficient calculated by the temporary correction coefficient calculation means Storage means; and correction coefficient calculation means for calculating a correction coefficient to be applied to the moving image frame based on the temporary correction coefficient stored by the temporary correction coefficient storage means. .

  Further, the present invention is characterized in that the correction coefficient calculating means calculates a correction coefficient applied to the frame of the moving image extracted based on a second reference.

  In addition, the present invention is characterized in that the first reference and the second reference are references related to a time interval for extracting a frame.

  Further, the present invention is characterized in that the correction coefficient calculation means changes the second reference based on a fluctuation amount of the temporary correction coefficient calculated by the temporary correction coefficient calculation means.

  Further, according to the present invention, the correction coefficient calculation means calculates a correction coefficient applied to the frame of the moving image by performing a weighted average of the temporary correction coefficients calculated by the temporary correction coefficient calculation means. It is characterized by.

  In the invention, it is preferable that the correction coefficient calculation unit applies a larger weight coefficient to a provisional correction coefficient for a frame having a small time difference from a frame to which the correction coefficient is applied when performing the weighted average. .

  According to the present invention, the correction coefficient calculation means calculates a correction coefficient applied to the frame of the moving image by interpolating the temporary correction coefficient calculated by the temporary correction coefficient calculation means. It is characterized by.

  Further, the present invention is characterized in that the correction coefficient calculation means applies a larger weight coefficient to a provisional correction coefficient for a frame having a small time difference from a frame to which the correction coefficient is applied when performing the interpolation calculation. .

  In addition, the present invention further includes a variation amount determination unit that determines an image variation amount of a frame, and the temporary correction coefficient calculation unit performs the second processing when the variation amount determination unit determines that the image variation amount is large. It is characterized by changing the standard.

  Further, the present invention is characterized in that the variation amount determining means determines the image variation amount of a frame based on a change in a temporary correction coefficient.

  In the invention, it is preferable that the correction coefficient calculation unit changes the first reference when the variation amount determination unit determines that the image variation amount is large.

  In the present invention, the correction coefficient calculation means may calculate the correction coefficient based on the magnitude of the image fluctuation amount when the fluctuation amount determination means determines that the image fluctuation amount is large. A weighting coefficient applied to the correction coefficient is set.

  In addition, the present invention further includes an input receiving unit that receives a setting related to the calculation of the temporary correction coefficient or an input of a setting related to the calculation of the correction coefficient, and the temporary correction coefficient calculating unit or the correction coefficient calculating unit includes the input A temporary correction coefficient or a correction coefficient is calculated based on the setting received by the receiving unit.

  The present invention is further characterized by further comprising correction coefficient transmitting means for transmitting the correction coefficient calculated by the correction coefficient calculating means.

  The present invention also applies a correction coefficient receiving means for receiving the correction coefficient transmitted by the correction coefficient transmitting means of the moving image correction coefficient calculating device, and applying the correction coefficient received by the correction coefficient receiving means to the frame of the moving image. And moving image correction means for correcting the frame of the moving image.

  The present invention is also a moving image correction coefficient calculation method for calculating a correction coefficient to be applied to a moving image frame, the frame extracted based on a first reference from the moving image frame. A temporary correction coefficient calculating step for calculating a temporary correction coefficient applied to the temporary correction coefficient, a temporary correction coefficient storing step for storing the temporary correction coefficient calculated by the temporary correction coefficient calculating step, and a temporary correction coefficient storing step. And a correction coefficient calculating step of calculating a correction coefficient applied to the moving image frame based on the provisional correction coefficient.

  The present invention is also a moving image correction coefficient calculation program for calculating a correction coefficient applied to a moving image frame, the frame extracted based on a first reference from the moving image frame. A temporary correction coefficient calculation procedure for calculating a temporary correction coefficient applied to the temporary correction coefficient, a temporary correction coefficient storage procedure for storing the temporary correction coefficient calculated by the temporary correction coefficient calculation procedure, and a temporary correction coefficient storage procedure. And a correction coefficient calculation procedure for calculating a correction coefficient to be applied to the frame of the moving image based on the provisional correction coefficient.

  According to the present invention, a temporary correction coefficient to be applied to a frame extracted based on the first criterion from among the frames of a moving image is calculated, the calculated temporary correction coefficient is stored, and stored. Since the correction coefficient to be applied to the moving image frame is calculated based on the provisional correction coefficient, the effect of improving the image quality and reducing the amount of calculation can be realized in a balanced manner. Play.

  According to the present invention, since the correction coefficient applied to the moving image frame extracted based on the second criterion is calculated, the calculation amount for calculating the correction coefficient can be further reduced. There is an effect that can be.

  Further, according to the present invention, since the first reference and the second reference are the standards related to the time interval for extracting frames, the image quality can be reduced by calculating the correction coefficient at a predetermined time interval. There is an effect that improvement and reduction of the calculation amount can be realized in a balanced manner.

  Further, according to the present invention, since the second reference is changed based on the calculated fluctuation amount of the temporary correction coefficient, correction is performed at appropriate intervals according to the magnitude of the temporary correction coefficient fluctuation. There is an effect that the coefficient can be calculated.

  Further, according to the present invention, the correction coefficient applied to the frame of the moving image is calculated by performing weighted averaging of the calculated temporary correction coefficient. There is an effect that reduction and improvement in image quality can be realized in a balanced manner.

  In addition, according to the present invention, when performing weighted averaging, a larger weighting factor is applied to a provisional correction factor for a frame to which a correction factor is applied and a frame having a smaller time difference, so that the correction factor is applied. Emphasizing the provisional correction coefficient of a frame that is temporally close to the frame provides an effect that the image quality can be improved.

  Further, according to the present invention, the correction coefficient applied to the frame of the moving image is calculated by performing an interpolation operation on the calculated temporary correction coefficient. There is an effect that reduction and improvement in image quality can be realized in a balanced manner.

  Further, according to the present invention, when performing the interpolation calculation, the provisional correction coefficient for the frame to which the correction coefficient is applied and the frame having a small time difference are applied with a larger weighting coefficient, so that the correction coefficient is applied. Emphasizing the provisional correction coefficient of a frame that is temporally close to the frame provides an effect that the image quality can be improved.

  Further, according to the present invention, since the image fluctuation amount of the frame is determined, and it is determined that the image fluctuation amount is large, the second reference is changed. In some cases, the image quality can be improved by changing the timing for calculating the correction coefficient.

  Further, according to the present invention, since the frame image fluctuation amount is determined based on the change in the temporary correction coefficient, there is an effect that the frame image fluctuation amount can be determined efficiently.

  Further, according to the present invention, when the image fluctuation amount is determined to be large, the first reference is changed, so that the correction coefficient can be further increased by changing the timing for calculating the temporary correction coefficient. It is possible to appropriately calculate and improve the image quality.

  Further, according to the present invention, when it is determined that the image variation amount is large, the weighting coefficient applied to the temporary correction coefficient is set based on the magnitude of the image variation amount when calculating the correction coefficient. As a result, the correction coefficient can be calculated more appropriately, and the image quality can be improved.

  Further, according to the present invention, a setting for calculating a temporary correction coefficient or an input of a setting for calculating a correction coefficient is received, and a temporary correction coefficient or a correction coefficient is calculated based on the received setting, respectively. Therefore, the setting specified by the user can be reflected in the provisional correction coefficient or the calculation of the correction coefficient.

  Further, according to the present invention, since the calculated correction coefficient is transmitted, there is an effect that the correction coefficient created by the own apparatus can be used by another apparatus.

  In addition, according to the present invention, since the transmitted correction coefficient is received and the received correction coefficient is applied to the moving image frame to correct the moving image frame, the correction calculated by another device is performed. By correcting the frame using the coefficient, the own apparatus does not need to calculate the correction coefficient, and the load on the own apparatus can be reduced.

FIG. 1 is an explanatory diagram for explaining the concept of a moving image correction coefficient calculation process according to the first embodiment. FIG. 2 is a functional block diagram illustrating a functional configuration of the moving image correction coefficient calculation apparatus 20 according to the first embodiment. FIG. 3 is an explanatory diagram for explaining the scene change detection process performed by the variation determination unit 25d. FIG. 4 is an explanatory diagram for explaining correction coefficient calculation processing when a scene change is detected. FIG. 5 is a diagram showing a situation of the usage rate of the scene change gamma value calculation frame when a scene change is detected. FIG. 6 is a flowchart of the process procedure of the moving image correction coefficient calculation process according to the first embodiment. FIG. 7 is a flowchart of a process procedure of the scene change detection gamma value calculation process shown in FIG. FIG. 8 is an explanatory diagram for explaining the concept of the moving image correction process of the moving image correction system according to the second embodiment. FIG. 9 is a functional block diagram of a functional configuration of the moving image correction system according to the second embodiment. FIG. 10 is a diagram illustrating the configuration of the computer system according to the third embodiment. FIG. 11 is a block diagram showing the configuration of the main body in the computer system shown in FIG.

  Exemplary embodiments of a moving image correction coefficient calculation device, a moving image correction device, a moving image correction coefficient calculation method, and a moving image correction coefficient calculation program according to the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, a correction coefficient (gamma value) for gamma correction is taken as an example of the correction coefficient, but the present invention is not limited to this, and a correction coefficient for color balance correction or a correction coefficient for saturation correction. The same processing can be performed for other correction coefficients.

  First, the concept of the moving image correction coefficient calculation process according to the first embodiment will be described. FIG. 1 is an explanatory diagram for explaining the concept of a moving image correction coefficient calculation process according to the first embodiment. The example of FIG. 1 shows an example of a moving image that is played back at 25 frames per second (1 frame at 0.04 seconds).

  In the first embodiment, first, a temporary gamma value calculation frame is extracted at a predetermined interval in order to calculate a temporary gamma value. In the example of FIG. 1, provisional gamma value calculation frames 1a to 1d are extracted every two seconds. Then, gamma values for the extracted temporary gamma value calculation frames 1a to 1d are calculated, and the calculated gamma value is set as a temporary gamma value.

  Here, a known technique is used to calculate the gamma value. For example, the literature “Juha Ktajamaki (the last a is a umlaut of a) and Pekka Laihanen,“ Image Dependent Gamma Selection Based on Color Palette Equalization and a Simple Lightness Model, ”Proc. Of 7th CIC, 301-306 (1999) The gamma value is calculated by a method as shown in FIG.

  Then, a temporary gamma value difference is calculated between adjacent temporary gamma value calculation frames (for example, between the temporary gamma value calculation frames 1a and 1b, between the temporary gamma value calculation frames 1b and 1c, etc.) The frame interval for calculating the gamma value is set according to the magnitude of the difference, and the gamma value calculation frames 2a to 2d and 3a to 3k for calculating the gamma value are extracted.

  Specifically, when the difference between the temporary gamma values is less than a first threshold (for example, 0.1), it is determined that the change in the image is small, and the interval between the gamma value calculation frames is set wide. .

  In the example of FIG. 1, the temporary gamma value difference between the temporary gamma value calculation frames 1a and 1b and the temporary gamma value difference between the temporary gamma value calculation frames 1b and 1c are less than 0.1. The intervals between the gamma value calculation frames 2a and 2b, between the gamma value calculation frames 2b and 2c, and between the gamma value calculation frames 2c and 2d are 0.67 seconds.

  On the other hand, when the difference between the temporary gamma values is equal to or larger than the first threshold value, it is determined that the image change is large, and the interval between the gamma value calculation frames is set to be narrow.

  In the example of FIG. 1, since the difference in the temporary gamma value between the temporary gamma value calculation frames 1c and 1d is less than 0.1, between the gamma value calculation frames 3a and 3b, between the gamma value calculation frames 3b and 3c, etc. The interval between gamma value calculation frames is 0.2 seconds.

  Then, the gamma value of the gamma value calculation frame is calculated by weighting the temporary gamma value and further performing interpolation calculation and weighted average. Note that the gamma value of the frame for which the gamma value has not been calculated is set to the value of the gamma value of the gamma value calculation frame immediately before that frame.

  Here, the weighting coefficient assigned to the temporary gamma value is set to a larger weighting coefficient for a temporary gamma value calculation frame that is temporally closer to the gamma value calculation frame for which the gamma value is to be calculated.

  For example, in the example of FIG. 1, a weighting factor other than 0 is set to the temporary gamma value of the temporary gamma value calculation frame within 4 seconds before and after the reproduction time of the gamma value calculation frame for calculating the gamma value. Yes.

  Specifically, as shown in FIG. 1, the magnitude of the weighting coefficient for the temporary gamma value is calculated using the weighting coefficient of the temporary gamma value calculation frame corresponding to the reproduction time of the gamma value calculation frame as a peak value. This is determined by a straight line connecting 0 and the peak when the weighting coefficient of the temporary gamma value calculation frame 4 seconds before and after the frame reproduction time is set to 0.

  The gamma value of the gamma value calculation frame is calculated by performing an interpolation operation using a temporary gamma value weighted by a weighting coefficient. Here, the gamma value is calculated by performing an interpolation operation. However, the gamma value may be calculated by performing a weighted average operation of temporary gamma values using a weighting coefficient.

  In this way, instead of calculating gamma values for all frames, frames are extracted at predetermined intervals to calculate temporary gamma values, and gamma values are calculated based on the calculated temporary gamma values. Since the gamma value used for correction is calculated, improvement in image quality and reduction in calculation amount can be realized in a balanced manner.

  Next, a functional configuration of the moving image correction coefficient calculation apparatus according to the first embodiment will be described. FIG. 2 is a functional block diagram illustrating a functional configuration of the moving image correction coefficient calculation apparatus 20 according to the first embodiment. The moving image correction coefficient calculation device 20 is a device that acquires a moving image acquired from the camera 10 and performs gamma correction processing on the acquired moving image.

  As illustrated in FIG. 2, the moving image correction coefficient calculation device 20 includes an interface unit 21, an input unit 22, a display unit 23, a storage unit 24, and a control unit 25.

  The interface unit 21 is an interface for acquiring moving image frame data from the camera 10. The input unit 22 is an input device such as a keyboard or a mouse, and the display unit 23 is a display device such as a display.

  The storage unit 24 is a storage device such as a hard disk device, and stores frame data 24a, temporary correction coefficient 24b, correction coefficient 24c, and correction frame data 24d. The frame data 24 a stores frame data of moving images acquired from the camera 10.

  The temporary correction coefficient 24b stores the temporary gamma value calculated for the temporary gamma value calculation frame, and the correction coefficient 24c is the gamma value of the gamma value calculation frame calculated based on the temporary gamma value. Is memorized. The corrected frame data 24d stores frame data corrected using a gamma value.

  The control unit 25 is a control unit that performs overall control of the moving image correction coefficient calculation device 20, and includes a moving image acquisition unit 25a, a temporary correction coefficient calculation unit 25b, a correction coefficient calculation unit 25c, a variation amount determination unit 25d, and a moving image correction. Part 25e.

  The moving image acquisition unit 25a acquires frame data of the moving image from the camera 10 and stores the frame data as frame data 24a in the storage unit 24.

  The temporary correction coefficient calculation unit 25b extracts a temporary correction coefficient calculation frame from the frame data 24a at a set time interval, calculates a temporary gamma value of the extracted temporary correction coefficient calculation frame, and calculates the calculated temporary gamma value. Is stored in the storage unit 24 as a temporary correction coefficient 24b.

  The correction coefficient calculation unit 25c extracts a correction coefficient calculation frame from the frame data 24a at set time intervals, and based on the temporary gamma value calculated by the temporary correction coefficient calculation unit 25b, the gamma value of the correction coefficient calculation frame And the calculated gamma value is stored in the storage unit 24 as the correction coefficient 24c.

  Specifically, the correction coefficient calculation unit 25c compares the temporary gamma value between adjacent temporary correction coefficient calculation frames, and when the absolute value of the difference between the temporary gamma values is equal to or greater than the first threshold value, It is determined that the image change is large, and the interval between correction coefficient calculation frames for calculating the gamma value is set narrow.

  If the absolute value of the difference between the temporary gamma values is less than the first threshold, the correction coefficient calculation unit 25c determines that the change in the image is small, and sets the interval between correction coefficient calculation frames wide. Then, the correction coefficient calculation unit 25c calculates the gamma value of the correction coefficient calculation frame by performing an interpolation operation or a weighted average operation using the weighted temporary gamma value.

  The fluctuation amount determination unit 25d checks whether or not the difference in the temporary gamma value between adjacent temporary correction coefficient calculation frames is equal to or greater than a predetermined threshold. If the difference is equal to or greater than the predetermined threshold, It is determined that there is a scene change with a large change. Here, the predetermined threshold is set to a value larger than the first threshold described above. When it is determined that there is a scene change, the fluctuation amount determination unit 25d requests the temporary correction coefficient calculation unit 25b and the correction coefficient calculation unit 25c to execute a scene change correction coefficient calculation process.

  FIG. 4 is an explanatory diagram for explaining correction coefficient calculation processing when a scene change is detected. As shown in FIG. 4, when a scene change is detected by the fluctuation amount determination unit 25d, the correction coefficient calculation unit 25c extracts the gamma value calculation frames 7a to 7i at a narrower interval than when there is no scene change, Gamma value calculation frames 7a to 7i are calculated.

  In the example of FIG. 4, when there is no scene change, the gamma value calculation frames 6a to 6f are extracted at intervals of 0.67 seconds, but when there is a scene change, the gamma value calculation frames 7a to 7i are extracted. , Extracted at intervals of 0.25 seconds.

  Further, the temporary correction coefficient calculation unit 25b extracts the temporary gamma value calculation frames 5a to 5h at a narrower interval and calculates a temporary gamma value at a narrower interval when a scene change is detected by the variation determination unit 25d. To do.

  In the example of FIG. 4, when there is no scene change, the temporary gamma value calculation frames 4a and 4b are extracted at intervals of 2.0 seconds, but when there is a scene change, the temporary gamma value calculation frames 5a to 5b. 5h is extracted at intervals of 0.29 seconds.

  FIG. 5 is a diagram showing a situation of the usage rate of the scene change gamma value calculation frame when a scene change is detected. As shown in FIG. 5, when a scene change is detected, the ratio of the gamma value calculation frames extracted at a narrower time interval than when there is no scene change gradually increases.

  This is because, as described with reference to FIG. 1, the gamma value of the gamma value calculation frame is calculated based on the result obtained by performing interpolation calculation or weighted averaging on a plurality of temporary gamma values. Therefore, it is possible to suppress a sudden change in the image quality of the moving image, and to make the image quality fluctuation natural.

  Returning to the description of FIG. 2, the moving image correction unit 25e performs gamma correction of the frame data 24a using the gamma value calculated by the correction coefficient calculation unit 25c and stored in the storage unit 24 as the correction coefficient 24c. A process of storing the frame data subjected to the gamma correction as the corrected frame data 24d is performed.

  Next, a processing procedure of moving image correction coefficient calculation processing according to the first embodiment will be described. FIG. 6 is a flowchart of the process procedure of the moving image correction coefficient calculation process according to the first embodiment.

  As shown in FIG. 6, first, the temporary correction coefficient calculation unit 25b of the moving image correction coefficient calculation apparatus 20 calculates temporary gamma values from the frame data 24a stored in the storage unit 24 at predetermined time intervals. The temporary gamma value calculation frame is extracted (step S101).

  Then, the temporary correction coefficient calculation unit 25b calculates a temporary gamma value for the extracted temporary gamma value calculation frame (step S102), and further calculates a difference in temporary gamma value between neighboring temporary gamma value calculation frames. (Step S103).

  Thereafter, the fluctuation amount determination unit 25d checks whether or not the difference in the temporary gamma value is less than the second threshold described with reference to FIG. 3 (step S104). If the difference is not less than the second threshold (step S104) S104, No), it is determined that there is a scene change with a large image change, and a gamma value calculation process at the time of scene change detection is performed (step S110). The gamma value calculation process when this scene change is detected will be described in detail with reference to FIG.

  In step S104, when the temporary gamma value difference is less than the second threshold value (step S104, Yes), the correction coefficient calculation unit 25c determines that the temporary gamma value difference is the first described in FIG. It is checked whether it is less than the threshold value (step S105). Here, the first threshold value is set to a value smaller than the second threshold value.

  If the difference between the temporary gamma values is less than the first threshold value (Yes in step S105), the correction coefficient calculation unit 25c sets the calculation interval for calculating the gamma value as the first interval (step S105). S106).

  If the difference between the temporary gamma values is not less than the first threshold (No at Step S105), the correction coefficient calculation unit 25c sets the calculation interval for calculating the gamma value as the second interval (Step S109). ). In this case, since it is determined that the change in the moving image is large, the second interval is set to be shorter than the first interval.

  After step S106 or step S109, the correction coefficient calculation unit 25c calculates a weighting coefficient to which the temporary gamma value is applied using the method described with reference to FIG. 1 (step S107). Thereafter, the correction coefficient calculation unit 25c performs an interpolation calculation or a weighted average calculation using the weighted temporary gamma value to which the weighting coefficient is applied, thereby performing gamma at the time interval set in step S106 or step S109. The value is calculated (step S108), and this moving image correction coefficient calculation process is terminated.

  Next, the process procedure of the gamma value calculation process at the time of scene change detection shown in FIG. 6 will be described. FIG. 7 is a flowchart of a process procedure of the scene change detection gamma value calculation process shown in FIG.

  As shown in FIG. 7, first, the temporary correction coefficient calculation unit 25b of the moving image correction coefficient calculation apparatus 20 re-extracts the temporary gamma value calculation frame at an interval shorter than the interval extracted at step S101 in FIG. Step S201).

  Then, the temporary correction coefficient calculation unit 25b calculates a temporary gamma value for the extracted temporary gamma value calculation frame (step S202), and further calculates a difference between the temporary gamma values (step S203). Here, the difference between the temporary gamma values is calculated according to the method described with reference to FIG.

  Subsequently, the correction coefficient calculation unit 25c sets the gamma value calculation interval to the third interval (step S204). Here, the third interval is set to be shorter than the second interval described in FIG.

  Thereafter, the correction coefficient calculation unit 25c checks whether or not the difference between the temporary gamma values calculated in step S203 is greater than or equal to the third threshold (step S205). If the difference between the temporary gamma values is not greater than or equal to the third threshold (No at Step S205), the correction coefficient calculation unit 25c calculates a first weighting coefficient to be applied to the temporary gamma values (Step S206).

  Specifically, in FIG. 1, the weighting coefficient of the temporary gamma value calculation frame at the fourth and the second seconds before and after the reproduction time of the gamma value calculation frame is set to 0, but the temporary gamma value difference is not greater than or equal to the third threshold value. In this case, for example, the correction coefficient calculation unit 25c sets the weighting coefficient of the temporary gamma value at the second and second seconds before and after the reproduction time of the gamma value calculation frame to 0, and increases the weighting coefficient of the peak value accordingly, By determining the weighting coefficient by a straight line connecting the peak values, the temporary gamma value of the temporary gamma value calculation frame that is temporally close to the gamma value calculation frame is more emphasized.

  In step S205, when the difference between the temporary gamma values is equal to or greater than the third threshold (step S205, Yes), the correction coefficient calculation unit 25c calculates a second weighting coefficient to be applied to the temporary gamma values. (Step S207).

  Specifically, when the difference in the temporary gamma value is greater than or equal to the third threshold, the correction coefficient calculation unit 25c, for example, weights the temporary gamma value for the first second before and after the reproduction time of the gamma value calculation frame. Temporary gamma value of the temporary gamma value calculation frame that is temporally close to the gamma value calculation frame by setting the coefficient to 0, increasing the weighting coefficient of the peak value, and determining the weighting coefficient by a straight line connecting 0 and the peak value To emphasize more.

  After step S206 or step S207, the correction coefficient calculation unit 25c performs the interpolation operation or the weighted average operation using the weighted temporary gamma value to which the weighting coefficient is applied, thereby setting the time set in step S204. A gamma value is calculated at intervals (step S208), and this scene change detection gamma value calculation process is terminated.

  Here, the time interval for calculating the temporary gamma value, the time interval for calculating the gamma value, the weighting factor, the threshold value, etc. are set in advance, and some of them are calculated in the course of the gamma value calculation process. Although it is supposed to be updated by the apparatus 20, the provisional correction coefficient calculation unit 25b, the correction coefficient calculation unit 25c, or the variation amount determination unit 25d accepts input of setting of these values from the user in the process of calculating the gamma value. The received setting may be reflected in the gamma value calculation process.

  As described above, in the first embodiment, the temporary correction coefficient calculation unit 25b calculates a temporary gamma value to be applied to a frame extracted at a predetermined time interval from a moving image frame, and stores it. The unit 24 stores the calculated temporary gamma value, and the correction coefficient calculation unit 25c calculates the gamma value applied to the frame of the moving image based on the stored temporary gamma value. Therefore, improvement in image quality and reduction in calculation amount can be realized in a balanced manner.

  In the first embodiment, since the correction coefficient calculation unit 25c calculates the gamma value applied to the moving image frames extracted at predetermined time intervals, the calculation amount for calculating the gamma value is reduced. Further reduction can be achieved.

  In the first embodiment, the correction coefficient calculation unit 25c changes the time interval for calculating the gamma value based on the calculated amount of change in the temporary gamma value. The gamma value can be calculated at an appropriate interval according to the size of.

  In the first embodiment, the correction coefficient calculation unit 25c calculates the gamma value applied to the frame of the moving image by performing weighted averaging of the calculated temporary gamma value. Reduction in the amount of calculation for calculating the value and improvement in image quality can be realized in a balanced manner.

  In the first embodiment, the correction coefficient calculation unit 25c applies a larger weight coefficient to a provisional gamma value for a frame to which a gamma value is applied and a frame having a small time difference when performing weighted averaging. The image quality can be improved by placing importance on the temporary gamma value of a frame that is temporally close to the frame to which the gamma value is applied.

  In the first embodiment, the correction coefficient calculation unit 25c calculates a gamma value to be applied to a moving image frame by performing an interpolation operation on the calculated temporary gamma value. Reduction in the amount of calculation for calculating the value and improvement in image quality can be realized in a balanced manner.

  In the first embodiment, the correction coefficient calculation unit 25c applies a larger weighting coefficient to a provisional gamma value for a frame to which the gamma value is applied and a frame having a small time difference when performing the interpolation calculation. The image quality can be improved by placing importance on the temporary gamma value of a frame that is temporally close to the frame to which the gamma value is applied.

  Further, in the first embodiment, when the variation amount determination unit 25d determines the image variation amount of the frame and determines that the image variation amount is large, the timing at which the correction coefficient calculation unit 25c calculates the gamma value is set. Since the change is made, the image quality can be improved by changing the timing for calculating the gamma value.

  Further, in the first embodiment, the fluctuation amount determination unit 25d determines the image fluctuation amount of the frame based on the temporary change in the gamma value, so that the image fluctuation amount of the frame can be efficiently determined. it can.

  Further, in the first embodiment, when the temporary correction coefficient calculation unit 25d determines that the image fluctuation amount is large, the timing for calculating the temporary gamma value is changed. When there is a change, the gamma value can be calculated more appropriately and the image quality can be improved.

  In the first embodiment, when the correction coefficient calculation unit 25c determines that the image fluctuation amount is large, the correction coefficient calculation unit 25c applies the temporary gamma value when calculating the gamma value based on the magnitude of the image fluctuation amount. Since the weighting factor to be set is set, the gamma value can be calculated more appropriately and the image quality can be improved.

  In the first embodiment, the temporary correction coefficient calculation unit 25b, the correction coefficient calculation unit 25c, or the fluctuation amount determination unit 25d receives a setting related to the calculation of the temporary gamma value or a setting related to the calculation of the gamma value, Since the temporary gamma value or gamma value is calculated based on the accepted setting, the setting designated by the user can be reflected in the calculation of the temporary gamma value or gamma value.

  In the first embodiment described above, the moving image correction coefficient calculating apparatus performs gamma correction of a moving image frame using the gamma value calculated by the own apparatus. The client device (moving image correction device) may select and acquire gamma value information suitable for the device from the device (moving image correction coefficient calculation device), and perform gamma correction.

  Therefore, in the second embodiment, a case will be described in which a client device acquires gamma value information suitable for its own device from a server device that calculates a gamma value.

  First, the concept of the moving image correction process of the moving image correction system according to the second embodiment will be described. FIG. 8 is an explanatory diagram for explaining the concept of the moving image correction process of the moving image correction system according to the second embodiment.

  As shown in FIG. 8, in this moving image correction system, the server device 30 calculates a gamma value, and the client device 40 acquires the gamma value calculated by the server device 30 to obtain a gamma value of the frame of the moving image. It is configured to perform correction.

  The server device 30 is adapted to the frame data 31 for which the gamma value is calculated, the correction coefficient 32 which is the gamma value calculated for the frame data 31, and the moving image display characteristics of the client device 40. The device-dependent correction coefficient 33 that is the calculated gamma value is stored.

  The client device 40 acquires the frame data 44 of the moving image to be reproduced from the frame data 31 stored in the server device, and acquires the gamma value 41 for the frame data 44 from the correction coefficient 32. Further, the client device 40 acquires, from the device-dependent correction coefficient 33, a device-dependent gamma value 42 calculated in accordance with the display characteristics of the moving image of the own device.

  Thereafter, the client device 40 combines the gamma value 41 acquired from the server device 30 and the device-dependent gamma value 42 to calculate a combined gamma value 43 used for gamma correction. Then, the client device 40 performs gamma correction of the frame data 44 using the composite gamma value 43, and acquires corrected frame data 45 that has been subjected to gamma correction.

  Next, a functional configuration of the moving image correction system according to the second embodiment will be described. FIG. 9 is a functional block diagram of a functional configuration of the moving image correction system according to the second embodiment. As shown in FIG. 9, in this moving image correction system, a server device 30 and a client device 40 are connected via a network 60 such as the Internet.

  The server device 30 is a device that calculates a gamma value, and includes an interface unit 35, an input unit 36, a display unit 37, a storage unit 38, and a control unit 39.

  The interface unit 35 is a network interface that exchanges data with the client device 40. The input unit 36 is an input device such as a keyboard or a mouse. The display unit 37 is a display device such as a display.

  The storage unit 38 is a storage device such as a hard disk device, and stores frame data 38a, a correction coefficient 38b, and a device-dependent correction coefficient 38c.

  The frame data 38a stores moving image frame data. The correction coefficient 38b stores the gamma value calculated as described in the first embodiment. The device-dependent correction coefficient 38c stores a device-dependent gamma value calculated according to the moving image display characteristics of each client device.

  The control unit 39 is a control unit that controls the server device 30 as a whole, and includes a correction coefficient calculation processing unit 39a and a data transmission unit 39b.

  The correction coefficient calculation processing unit 39a is a processing unit that calculates the gamma value of the frame data 38a. The correction coefficient calculation processing unit 39a includes the moving image acquisition unit 25a, the temporary correction coefficient calculation unit 25b, and the correction coefficient of the moving image correction coefficient calculation device 20 illustrated in FIG. The calculation unit 25c and the variation determination unit 25d have the same functions.

  The data transmission unit 39b acquires the frame data 44, the gamma value 41, and the device-dependent gamma value 42 for which the transmission request has been received by the client device 40 from the frame data 38a, the correction coefficient 38b, and the device-dependent correction coefficient 38c, and the client device 40 Send to.

  The client device 40 is a device that acquires the gamma value calculated by the server device 30 and performs gamma correction of the frame of the moving image, and includes an interface unit 46, an input unit 47, a display unit 48, a storage unit 49, and a control unit. 50.

  The interface unit 46 is a network interface that exchanges data with the server device 30. The input unit 47 is an input device such as a keyboard or a mouse. The display unit 48 is a display device such as a display.

  The storage unit 49 is a storage device such as a hard disk device, and stores frame data 49a, a correction coefficient 49b, a device-dependent correction coefficient 49c, a combined correction coefficient 49d, and correction frame data 49e.

  The frame data 49a, the correction coefficient 49b, and the device-dependent correction coefficient 49c are data of the frame data 44, the gamma value 41, and the device-dependent gamma value 42 acquired from the server device 30.

  The composite correction coefficient 49d is the composite gamma value 43 obtained by combining the gamma value 41 and the device-dependent gamma value 42 as described with reference to FIG. The corrected frame data 49e is frame data that has been subjected to gamma correction.

  The control unit 50 is a control unit that controls the entire client device 40, and includes a data reception unit 50a and a moving image correction unit 50b.

  The data receiving unit 50a requests the server device 30 to transmit the frame data 44, the gamma value 41, or the device-dependent gamma value 42, and when those data are transmitted by the server device 30, the data Receive.

  The moving image correction unit 50b performs gamma correction of the frame data 49a using the gamma value stored in the storage unit 49 as the correction coefficient 49b, the device-dependent correction coefficient 49c, or the composite correction coefficient 49d, and the frame subjected to the gamma correction. A process of storing data as correction frame data 49e is performed.

  As described above, in the second embodiment, since the data transmission unit 39b of the server device 30 transmits the calculated gamma value to the client device 40, the gamma value created by itself is transmitted to another device. Can be used.

  In the second embodiment, the data receiving unit 50a of the client device 40 receives the transmitted gamma value, and corrects the moving image frame by applying the received gamma value to the moving image frame. Therefore, by correcting the frame using the gamma value calculated by the server device 30, the own device does not need to calculate the gamma value, and the load on the own device can be reduced.

  By the way, the moving image correction coefficient calculation apparatus, server apparatus, and client apparatus described in the first or second embodiment can be realized by executing a program prepared in advance on a computer system such as a personal computer or a workstation. it can.

  Therefore, in the third embodiment, a computer system that executes a program that causes a computer system to perform the same function as the moving image correction coefficient calculation device, the server device, and the client device described in the first or second embodiment will be described.

  FIG. 10 is a diagram illustrating the configuration of the computer system according to the third embodiment. FIG. 11 is a block diagram illustrating the configuration of the main body in the computer system illustrated in FIG.

  As shown in FIG. 10, the computer system 100 includes a main body 101, a display 102 for displaying information such as an image on a display screen 102 a according to an instruction from the main body 101, and various information on the computer system 100. And a mouse 104 for designating an arbitrary position on the display screen 102a of the display 102.

  As shown in FIG. 11, the main body 101 in the computer system 100 includes a CPU 121, a RAM 122, a ROM 123, a hard disk drive (HDD) 124, a CD-ROM drive 125 that receives a CD-ROM 109, and a flexible disk. An FD drive 126 that accepts an (FD) 108; an I / O interface 127 that connects the display 102, keyboard 103, and mouse 104; and a LAN interface 128 that connects to a local area network or wide area network (LAN / WAN) 106 Prepare.

  Further, a modem 105 for connecting to a public line 107 such as the Internet is connected to the computer system 100, and another computer system (PC) 111 and server 112 are connected via a LAN interface 128 and a LAN / WAN 106. In addition, a printer 113 and the like are connected.

  The computer system 100 implements functions similar to those of the moving image correction coefficient calculation device, the server device, and the client device by reading and executing a program recorded in a predetermined recording medium.

  Here, the predetermined recording medium is not limited to “portable physical medium” such as flexible disk (FD) 108, CD-ROM 109, MO disk, DVD disk, magneto-optical disk, IC card, etc. Connected to internal and external hard disk drives (HDD) 124, “fixed physical media” such as RAM 122 and ROM 123, public line 107 connected via modem 105, other computer system 111 and server 112 Any recording medium that records a program that can be read by the computer system 100, such as a “communication medium” that holds the program in a short period of time when the program is transmitted, such as a LAN / WAN 106 that is used.

  That is, this program is recorded on a recording medium such as the above-mentioned “portable physical medium”, “fixed physical medium”, “communication medium”, etc. so that it can be read by a computer. By reading and executing the program from such a recording medium, functions similar to those of the moving image correction coefficient calculating device, the server device, and the client device are realized.

  The program is not limited to be executed by the computer system 100, and when the other computer system 111 or the server 112 executes the program, or these cooperate to execute the program. In such a case, the present invention can be similarly applied.

  Although the embodiments of the present invention have been described so far, the present invention can be implemented in various different embodiments within the scope of the technical idea described in the claims other than the embodiments described above. Is also good.

  In addition, among the processes described in this embodiment, all or part of the processes described as being performed automatically can be performed manually, or the processes described as being performed manually can be performed. All or a part can be automatically performed by a known method.

  In addition, the processing procedure, control procedure, specific name, and information including various data and parameters shown in the above-described document and drawings can be arbitrarily changed unless otherwise specified.

  Each component of each illustrated device is functionally conceptual and does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each device is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed or arbitrarily distributed in arbitrary units according to various loads or usage conditions. Can be integrated and configured.

  Further, all or any part of each processing function performed in each device may be realized by a CPU and a program analyzed and executed by the CPU, or may be realized as hardware by wired logic.

(Supplementary Note 1) A moving image correction coefficient calculating apparatus for calculating a correction coefficient applied to a frame of a moving image,
Temporary correction coefficient calculating means for calculating a temporary correction coefficient applied to a frame extracted based on a first reference from the frames of the moving image;
Temporary correction coefficient storage means for storing the temporary correction coefficient calculated by the temporary correction coefficient calculation means;
Correction coefficient calculation means for calculating a correction coefficient applied to the frame of the moving image based on the temporary correction coefficient stored by the temporary correction coefficient storage means;
A moving image correction coefficient calculation apparatus comprising:

(Additional remark 2) The said correction coefficient calculation means calculates the correction coefficient applied with respect to the frame of the said moving image extracted based on the 2nd reference | standard, The moving image correction of Additional remark 1 characterized by the above-mentioned. Coefficient calculation device.

(Supplementary note 3) The moving image correction coefficient calculation apparatus according to supplementary note 2, wherein the first reference and the second reference are references relating to a time interval for extracting a frame.

(Supplementary note 4) The supplementary note 2 or 3, wherein the correction coefficient calculating means changes the second reference based on a fluctuation amount of the temporary correction coefficient calculated by the temporary correction coefficient calculating means. The moving image correction coefficient calculation apparatus described.

(Additional remark 5) The said correction coefficient calculation means calculates the correction coefficient applied with respect to the flame | frame of the said moving image by carrying out the weighted average of the temporary correction coefficient calculated by the said temporary correction coefficient calculation means. The moving image correction coefficient calculation apparatus according to any one of Supplementary notes 1 to 4.

(Additional remark 6) The said correction coefficient calculation means applies a larger weight coefficient to the provisional correction coefficient with respect to the flame | frame with a small time difference, and the frame where a correction coefficient is applied, when performing the said weighted average. The moving image correction coefficient calculation apparatus described in 1.

(Supplementary note 7) The correction coefficient calculating means calculates a correction coefficient to be applied to the frame of the moving image by interpolating the temporary correction coefficient calculated by the temporary correction coefficient calculating means. The moving image correction coefficient calculation apparatus according to any one of Supplementary notes 1 to 4.

(Additional remark 8) The said correction coefficient calculation means applies a larger weighting coefficient to the provisional correction coefficient with respect to the flame | frame to which a correction coefficient is applied, and a flame | frame with a small time difference, when performing the said interpolation calculation. The moving image correction coefficient calculation apparatus described in 1.

(Additional remark 9) It further has the fluctuation amount determination means which determines the image fluctuation amount of a flame | frame, The said temporary correction coefficient calculation means uses a 2nd reference | standard when the fluctuation amount determination means determines with an image fluctuation amount being large. The moving image correction coefficient calculation apparatus according to any one of supplementary notes 1 to 8, wherein the moving image correction coefficient calculation apparatus is changed.

(Supplementary note 10) The moving image correction coefficient calculating apparatus according to supplementary note 9, wherein the fluctuation amount determination means determines the image fluctuation amount of a frame based on a change in a temporary correction coefficient.

(Supplementary note 11) The moving image according to supplementary note 9 or 10, wherein the correction coefficient calculation unit changes the first reference when the variation amount determination unit determines that the image variation amount is large. Correction coefficient calculation device.

(Additional remark 12) The correction coefficient calculating means, when the fluctuation amount determining means determines that the image fluctuation amount is large, the provisional correction when calculating the correction coefficient based on the magnitude of the image fluctuation amount 12. The moving image correction coefficient calculation apparatus according to Supplementary Note 9, 10 or 11, wherein a weighting coefficient applied to the coefficient is set.

(Additional remark 13) It further has the input reception means to receive the setting input which concerns on the setting concerning calculation of a temporary correction coefficient, or calculation of a correction coefficient, The said temporary correction coefficient calculation means or the said correction coefficient calculation means is the said input reception means 13. The moving image correction coefficient calculation device according to any one of appendices 1 to 12, wherein a temporary correction coefficient or a correction coefficient is calculated based on the setting received by each of the above.

(Supplementary note 14) The moving image correction coefficient calculating device according to any one of supplementary notes 1 to 13, further comprising correction coefficient transmitting means for transmitting the correction coefficient calculated by the correction coefficient calculating means.

(Supplementary Note 15) Correction coefficient receiving means for receiving the correction coefficient transmitted by the correction coefficient transmitting means of the moving image correction coefficient calculating apparatus according to Supplementary Note 14, and the correction coefficient received by the correction coefficient receiving means as a frame of a moving image A moving image correction apparatus comprising: a moving image correction unit that applies the correction to a frame of the moving image.

(Supplementary Note 16) A moving image correction coefficient calculation method for calculating a correction coefficient applied to a frame of a moving image,
A temporary correction coefficient calculating step of calculating a temporary correction coefficient applied to a frame extracted based on a first reference from the frames of the moving image;
A temporary correction coefficient storage step for storing the temporary correction coefficient calculated by the temporary correction coefficient calculation step;
A correction coefficient calculating step for calculating a correction coefficient applied to the frame of the moving image based on the temporary correction coefficient stored by the temporary correction coefficient storage step;
A moving image correction coefficient calculation method comprising:

(Supplementary note 17) A moving image correction coefficient calculation program for calculating a correction coefficient applied to a frame of a moving image,
A temporary correction coefficient calculation procedure for calculating a temporary correction coefficient to be applied to a frame extracted based on a first criterion from the frames of the moving image;
A temporary correction coefficient storage procedure for storing the temporary correction coefficient calculated by the temporary correction coefficient calculation procedure;
A correction coefficient calculation procedure for calculating a correction coefficient to be applied to the frame of the moving image based on the temporary correction coefficient stored by the temporary correction coefficient storage procedure;
A computer-executable program for calculating a moving image correction coefficient.

  As described above, the moving image correction coefficient calculation device, the moving image correction device, the moving image correction coefficient calculation method, and the moving image correction coefficient calculation program according to the present invention achieve a good balance between improving the image quality and reducing the amount of calculation. Therefore, the present invention is useful for a moving image correction coefficient calculation system and a moving image correction system.

DESCRIPTION OF SYMBOLS 10 Camera 20 Moving image correction coefficient calculation apparatus 21 Interface part 22 Input part 23 Display part 24 Storage part 24a Frame data 24b Temporary correction coefficient 24c Correction coefficient 24d Correction frame data 25 Control part 25a Moving image acquisition part 25b Temporary correction coefficient calculation part 25c Correction coefficient calculation unit 25d Fluctuation amount determination unit 25e Moving image correction unit 30 Server device 35 Interface unit 36 Input unit 37 Display unit 38 Storage unit 38a Frame data 38b Correction coefficient 38c Device dependent correction coefficient 39 Control unit 39a Correction coefficient calculation processing unit 39b Data transmission unit 40 Client device 46 Interface unit 47 Input unit 48 Display unit 49 Storage unit 49a Frame data 49b Correction coefficient 49c Device dependent correction coefficient 49d Composite correction coefficient 49e Correction frame data 50 Control unit 50a data receiving unit 50b moving image correcting unit

Claims (3)

A moving image correction coefficient calculating apparatus for calculating a correction coefficient applied to a frame of a moving image,
Temporary correction coefficient calculation means for calculating a temporary correction coefficient applied to a frame extracted based on a predetermined interval as a first reference from the frames of the moving image;
A correction coefficient to be applied to a frame extracted based on the second criterion, which is shorter than the first criterion, from the frames of the moving image, and a time difference from a frame to which the correction factor is applied. For a frame in which the temporary correction coefficient for a small frame is calculated by interpolation calculation or weighted average of the temporary correction coefficient calculated by the temporary correction coefficient calculation means using a larger weighting coefficient, and the correction coefficient is not calculated A correction coefficient calculation means for using the correction coefficient of the frame in which the correction coefficient is calculated immediately before the frame as the correction coefficient of the frame;
A moving image correction coefficient calculation apparatus comprising: When the fluctuation amount of the temporary correction coefficient calculated by the temporary correction coefficient calculation means is larger than a second threshold (second threshold> first threshold), the first frame is selected from the frames of the moving image. A fluctuation amount determining means for calculating a fluctuation amount of a temporary correction coefficient applied to a re-extracted frame based on an interval shorter than the reference of
The correction coefficient calculation means is a weighting coefficient applied to a temporary correction coefficient for a frame to which the correction coefficient is applied and a frame having a small time difference as the fluctuation amount of the temporary correction coefficient calculated by the fluctuation amount determination means is larger. The moving image correction coefficient calculation apparatus according to claim 1, wherein the weighting coefficient is set so as to increase. An input receiving means for receiving an input of the first reference and the second reference;
The temporary correction coefficient calculating means or the correction coefficient calculating means calculates a temporary correction coefficient or a correction coefficient based on the first reference and the second reference received by the input receiving means, respectively. The moving image correction coefficient calculation apparatus according to claim 2, wherein

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