JP6101939B2 - Signal processing apparatus and signal processing method - Google Patents

Description

  The present disclosure relates to a signal processing device and a signal processing method for performing signal processing on input content data.

  Patent Document 1 discloses a display device, a display control method, and a program. The display device includes a display unit that outputs an image signal and a signal processing unit that executes control of the image signal output to the display unit. The signal processing unit corresponds to an elapsed time from the observation start time of the display unit. Thus, control for gradually lowering the color temperature of the image signal is executed. By lowering the color temperature, it is possible to reduce the blue component and reduce user fatigue.

JP 2013-257457 A

  The present disclosure provides a signal processing device capable of suppressing the discomfort of color change in an image region while reducing fatigue of a user who views displayed content data.

  The signal processing device according to the present disclosure divides the display area of the content data into a plurality of areas, the first ratio of the display area to the display area of the first area where the characters are mainly displayed, and the display area mainly other than the characters Has a calculation unit for calculating a second ratio of the second area to the display area. Further, a setting unit that sets the target color temperature of the content data and a conversion unit that changes the color temperature of the content data to the target color temperature based on the first ratio and the second ratio are provided.

  The signal processing device according to the present disclosure is effective in suppressing the uncomfortable feeling of color change in the image area while reducing fatigue of the user who views the displayed content data.

The block diagram which shows the example of 1 structure of the display apparatus in 1st Embodiment The figure which shows an example of the density histogram of the 1st area | region in 1st Embodiment. The figure which shows an example of the density histogram of the 2nd area | region in 1st Embodiment. The flowchart for demonstrating an example of operation | movement of the calculation part in 1st Embodiment The flowchart for demonstrating an example of operation | movement of the setting part in 1st Embodiment The figure explaining an example of the color temperature setting in 1st Embodiment Explanatory drawing of an example of the color temperature conversion method of the conversion part in 1st Embodiment Explanatory drawing of the other example of the color temperature conversion method of the conversion part in 1st Embodiment The figure which shows the color temperature change in 1st Embodiment The block diagram which shows the example of 1 structure of the display apparatus in 2nd Embodiment The figure which shows an example of the color temperature setting in 2nd Embodiment The block diagram which shows the example of 1 structure of the display apparatus in 3rd Embodiment The figure which shows an example of the color temperature setting in 3rd Embodiment

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

  The inventor provides the accompanying drawings and the following description in order for those skilled in the art to fully understand the present disclosure, and is not intended to limit the subject matter described in the claims. Absent.

(First embodiment)
Hereinafter, the first embodiment will be described with reference to FIGS.

[1-1. Constitution]
FIG. 1 is a block diagram showing the configuration of the display device 1 according to the first embodiment. As illustrated in FIG. 1, the display device 1 includes an acquisition unit 100, a signal processing device 10, a display control unit 104, and a display unit 105. The signal processing apparatus 10 includes a calculation unit 101, a setting unit 102, and a conversion unit 103.

  The acquisition unit 100 is an input unit for content data. Here, the content data is digital information expressed by video, images, characters, or a combination thereof. For example, it is data in a file format conforming to a standard such as MPEG, JPEG, PDF, BMP.

  The calculation unit 101 divides the display area of the content data input from the acquisition unit 100 into a plurality of display areas, and a first ratio of the first area in the display area where characters are mainly displayed to the display area, A second ratio of the second area where mainly non-characters such as images are displayed to the display area is calculated. Here, “characters are mainly displayed” means that characters are displayed in an area that is 1/2 or more of the display area. Similarly, “non-characters are mainly displayed” indicates that non-characters are displayed in an area of ½ or more of the display area. It should be noted that the ratio of characters or characters other than the characters shown in the display area for determining the first area and the second area is not limited to ½.

  The setting unit 102 sets a target color temperature for displaying content data according to the first ratio and the second ratio calculated by the calculation unit 101. Note that the color temperature indicates a hue when a gray gradation including white is displayed. When the color temperature is low, the display is reddish, and when the color temperature is high, the display is blue. The color temperature in the present disclosure indicates not only the color on the black body radiation locus represented on the chromaticity diagram but also the color of the coordinates including the vicinity of the black body radiation locus which is the so-called correlated color temperature.

  The conversion unit 103 changes the color temperature when the content data acquired by the acquisition unit 100 is displayed to the target color temperature set by the setting unit 102. The change in the color temperature can be changed immediately to the set color temperature, but may be changed gradually to the target color temperature with the passage of time.

  The display control unit 104 performs processing for displaying the content data whose color temperature has been changed by the conversion unit 103 on the display unit 105 in the subsequent stage.

  The display unit 105 is a display, and includes, for example, a liquid crystal display, an organic EL display, or a plasma display.

[1-2. Operation]
The operation of the signal processing apparatus configured as described above will be described below.

[1-2-1. Operation of calculation unit]
FIG. 2 is a diagram illustrating an example of the density histogram of the first region in the first embodiment. FIG. 3 is a diagram illustrating an example of the density histogram of the second region in the first embodiment. 2 and 3, the horizontal axis indicates the density value, and the vertical axis indicates the frequency of each density value.

  As shown in FIG. 2, the density histogram of the first area in which characters are mainly displayed is divided into two peaks, with the density values of the character part and the background part gathering. Further, as shown in FIG. 3, the density value varies as a whole in the area where the image which is an example of the second area is displayed.

  The calculation unit 101 uses the feature of the density histogram of the first region shown in FIG. 2 and the feature of the density histogram of the second region shown in FIG. 3 to determine which region the discrimination target region corresponds to. Determine.

  Here, the density value may be obtained by adding and averaging the signal levels of the RGB signals, or may be a luminance value obtained from the RGB signals. The luminance value is expressed by the following (Equation 1), for example.

(Equation 1)
Luminance value = 0.3R + 0.6G + 0.1B
Here, in (Equation 1), R, G, and B indicate the signal levels of the red signal, the green signal, and the blue signal, respectively.

  Further, the calculation unit 101 may add determination based on the edge amount in the area in addition to determination of the area based on the density histogram. The calculation unit 101 determines a region using the fact that there are more large edge changes than small edge changes in the first region and many small edge changes in the second region.

  The calculation unit 101 calculates the ratio of the first area and the second area in the display area from the first area number and the second area number obtained by the area determination method described in the above example. .

  In the calculation of the ratio, the same background color area as that of the first area and a margin where no character exists may be included in the second area, or included in both the first and second areas. You may not.

  In addition, the calculation unit 101 may determine that a region in which the background saturation of the first region is equal to or greater than a predetermined value is not the first region.

  FIG. 4 is a flowchart for explaining an example of the operation of the calculation unit 101 according to the first embodiment. FIG. 4 is an example of a processing flow when the background color of the first region is considered. FIG. 4 shows an example in which a density histogram is used for region discrimination.

  The calculation unit 101 divides the display area of the content data into a plurality of predetermined unit areas, and determines whether each area is a first area or a second area.

  (Step S401) The calculation unit 101 reads the target area and calculates a feature amount (for example, a density histogram) of the area.

  (Step S402) The calculation unit 101 determines whether the region is the first region based on the feature amount calculated in step S401. If the calculation unit 101 determines that the region is not the first region, the calculation unit 101 proceeds to step S403. If the calculation unit 101 determines that the region is the first region, the calculation unit 101 proceeds to step S404.

  (Step S403) The calculation unit 101 counts the area as the second area, and proceeds to step S406.

  (Step S404) The calculation unit 101 determines whether the background saturation in the region is equal to or greater than a predetermined value. If the calculation unit 101 determines that the background saturation is equal to or greater than the predetermined value, the calculation unit 101 does not count the region as the first region, and proceeds to step S406. If the background saturation is smaller than the predetermined value, the calculation unit 101 proceeds to step S405.

  (Step S405) The calculation unit 101 counts the area as the first area, and proceeds to step S406.

  (Step S406) The calculation unit 101 determines whether or not the determination of all areas has been completed, and proceeds to step S407 if it has been completed. If the determination of all areas has not been completed, the calculation unit 101 returns to step S401.

  (Step S407) The calculation unit 101 calculates the first ratio and the second ratio from the count number of the first area and the count number of the second area.

[1-2-2. Operation of the setting unit]
FIG. 5 is a flowchart for explaining an example of the operation of the setting unit 102.

  (Step S501) The setting unit 102 proceeds to step S502 if the first ratio is greater than or equal to the second ratio, and proceeds to step S503 if the second ratio is large.

  (Step S502) The setting unit 102 sets the color temperature of the first region to 3000K to 5000K. For example, if the first ratio is 100%, the color temperature is set to 3000K. If the first ratio is about 50%, the color temperature is set to 5000K. Further, when the first ratio is between 50% and 100%, a color temperature of 3000K to 5000K is set according to the ratio.

  (Step S503) The setting unit 102 sets the color temperature of the second region to 5000K to 6500K. For example, if the second ratio is 100%, the color temperature is set to 6500K. If the second ratio is about 50%, the color temperature is set to 5000K. Further, when the second ratio is between 50% and 100%, a color temperature of 5000K to 6500K is set according to the ratio.

  FIG. 6 is a diagram illustrating an example of color temperature setting.

  In FIG. 6A, since the first ratio is between 50% and 100%, the color temperature is set between 3000K and 5000K. In the case of the figure, it is set to a value close to 3000K. In FIG. 6B, since the first ratio is about 50%, the color temperature is set to 5000K. In FIG. 6C, since the second ratio is between 50% and 100%, the color temperature is set between 5000K and 6500K. In the case of the figure, it is set to a value close to 6500K.

  As shown in FIG. 6, the color temperature is set lower as the first ratio in the display area is larger.

[1-2-3. Operation of conversion unit]
FIG. 7 is a diagram illustrating an example of a color temperature conversion method of the conversion unit 103 according to the first embodiment. FIG. 7 shows an example in which the displayed color temperature is 5000K when the RGB signals are set to the same level. When changing the color temperature, each RGB signal is multiplied by a predetermined gain to change the RGB signal ratio. When increasing the color temperature, the level of the B signal is increased and the level of the R signal is decreased. When the color temperature is lowered, the level of the B signal is lowered and the level of the R signal is raised.

  FIG. 8 is a diagram illustrating another example of the color temperature conversion method of the conversion unit 103 according to the first embodiment. FIG. 8 shows an example in which the displayed color temperature is 9000K when the RGB signals are at the same level. When the color temperature is lowered, each of the RGB signals is multiplied by a predetermined gain to change the levels of the B and G signals.

  FIG. 9 is a diagram illustrating a change in color temperature in the first embodiment. As shown in FIG. 9, it is a figure which shows the example when the conversion part 103 gives a color temperature change gradually with progress of time. In FIG. 9, A is the color temperature when the first ratio is large. C is the color temperature when the second ratio is large. B is the color temperature when the first ratio and the second ratio are approximately the same. The target color temperature is a lower color temperature when the first ratio is large (color temperature A in FIG. 9), and is a higher color temperature when the second ratio is large (color temperature C in FIG. 9). ing. In FIG. 9, it can be seen that the color temperatures A to C draw a gentle curve toward the target color temperature and gradually change the color temperature over time. In this way, by gradually changing the color temperature, it is possible to change the user so that the user does not feel uncomfortable using the adaptability that the user who is looking at the display unit 105 adapts to the color.

[1-3. Effect]
As described above, in the present embodiment, calculation unit 101 divides the display area of content data into a plurality of areas, and each area includes a first area where characters are mainly displayed, and an image other than mainly characters such as images. A second area to be displayed is determined, and a first ratio of the first area to the display area and a second ratio of the second area to the display area are set. The setting unit 102 sets a target color temperature for displaying content data according to the first ratio and the second ratio calculated by the calculation unit 101. The conversion unit 103 changes the color temperature when displaying content data to the target color temperature set by the setting unit 102.

  Thus, in the content data, when the first ratio is large, the color temperature setting decrease range is set large, and when the second ratio is large, the color temperature setting decrease range is decreased. Therefore, when the first region is large, the blue light emission component that is supposed to increase user fatigue can be greatly reduced. In addition, when the second area is large, it is possible to display so as to reduce the blue light emission component and suppress a sense of discomfort in the original color of the image. Here, the blue light-emitting component is a light component having a wavelength of about 400 nm to 500 nm, for example, called blue light.

  Further, in the present embodiment, when the background saturation of the first area is equal to or greater than a predetermined value, the calculation unit 101 determines that the area is not the first area.

  As a result, even if it is determined as the first area by the density value histogram or the like, if the background saturation is equal to or higher than a predetermined value, it is not determined as the first area, and the decrease in the color temperature is reduced. . For this reason, it is possible to reduce the blue light emission component and obtain a display that does not greatly break the relationship between the character and the background color.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to FIGS.

[2-1. Constitution]
FIG. 10 is a block diagram illustrating a configuration example of the display device 2 according to the second embodiment. As illustrated in FIG. 10, the display device 2 includes an acquisition unit 100, a signal processing device 20, a display control unit 104, and a display unit 105. The signal processing device 20 includes a calculation unit 101, a setting unit 202, and a conversion unit 203. Here, the same reference numerals are given to components that perform the same operations as those in the first embodiment, and descriptions thereof are omitted. In the present embodiment, operations of the setting unit 202 and the conversion unit 203 are mainly described.

  The setting unit 202 sets a target color temperature when the display unit 105 displays content data according to the first ratio and the second ratio calculated by the calculation unit 101. After calculating the next target color temperature, the setting unit 202 sets a color temperature between the current target color temperature and the next target color temperature as the target color temperature.

[2-2. Operation]
The operation of the signal processing apparatus configured as described above will be described below.

  FIG. 11 is a diagram illustrating an example of a color temperature setting method according to the second embodiment.

  In FIG. 11, the horizontal axis represents time, and the content data is displayed on the display unit 105 in order of content data A from time 0, content data B from time t2, and content data C from time t4. As shown in FIG. 11, the setting unit 202 calculates the target color temperature of 6500K for the content data A, 4000K for the content data B, and 5000K for the content data C by the method of the first embodiment. To do.

  First, the setting unit 202 sets the target color temperature 6500K of the content data A. Next, when the setting unit 202 calculates the target color temperature of the content data B at the time t1 until the time t2, the target color temperature is set to the target color temperature 6500K of the content data A and the target color temperature 4000K of the content data B. The color temperature C1 is set in between. Next, when the content data B is displayed from time t2, the setting unit 202 sets the target color temperature to 4000K. Further, when the setting unit 202 calculates the target color temperature of the content data C at time t3 until time t4, the setting color temperature is set between the target color temperature 4000K of the content data B and the target color temperature 5000K of the content data C. Is set to a color temperature C2. When the content data C is displayed from time t4, the setting unit 202 sets the target color temperature to 5000K. When the setting unit 202 calculates the target color temperature of the next content (not shown) at time t5 until the display of the content data C is completed, the setting unit 202 sets the target color temperature to the target color temperature 5000K of the content data C and the next content. Is set to a color temperature C3 between the target color temperature and the target color temperature.

  As shown in FIG. 11, the conversion unit 203 changes the color temperature of the content data A so as to approach the target color temperature 6500K at the start of display. Next, the conversion unit 203 changes the color temperature of the content data A to approach the target color temperature C1 from time t1. Next, the conversion unit 203 changes the color temperature of the content data B so as to approach the target color temperature 4000K from time t2. Next, the conversion unit 203 changes the color temperature of the content data B so as to approach the target color temperature C2 from time t3. Further, the conversion unit 203 changes the color temperature of the content data C so as to approach the target color temperature 5000K from time t4. The conversion unit 203 changes the color temperature of the content data C so as to approach the target color temperature C3 from time t5.

[2-3. Effect]
As described above, in the present embodiment, the setting unit 202 sets the target color temperature according to the first ratio and the second ratio calculated by the calculation unit 201. When the setting unit 202 calculates the target color temperature of the content data to be displayed next, the setting unit 202 is currently displaying the color temperature between the target color temperature of the currently displayed content data and the target color temperature of the content data to be displayed next. Set as the target color temperature of the content data. The conversion unit 203 changes the color temperature of the display content so as to approach the target color temperature set by the setting unit 202.

  As a result, even if the difference between the target color temperature set for the currently displayed content data and the target color temperature set for the next displayed content data is large, the display of the content data is switched. The change to the next color temperature can be initiated before, avoiding a sudden change in color temperature. For this reason, it is possible to reduce the blue light emitting component and to suppress the uncomfortable feeling of the color received by the user that occurs when the color temperature changes greatly.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to FIGS.

[3-1. Constitution]
FIG. 12 is a block diagram illustrating a configuration example of the display device 3 according to the third embodiment. As illustrated in FIG. 12, the display device 3 includes an acquisition unit 100, a signal processing device 30, a display control unit 104, and a display unit 105. The signal processing device 30 includes a calculation unit 101, a setting unit 302, a conversion unit 103, and a detection unit 300. Here, the same reference numerals are given to components that perform the same operations as those in the first embodiment, and descriptions thereof are omitted. In the present embodiment, operations of the setting unit 302 and the detection unit 300 will be mainly described.

  The detection unit 300 detects the color temperature of the ambient light in the environment where the display device 3 is used, using an optical sensor or the like.

  The setting unit 302 sets a target color temperature for displaying content data according to the first ratio and the second ratio calculated by the calculation unit 101 and the color temperature of the ambient light detected by the detection unit 300. .

  The conversion unit 103 changes the color temperature of the content data to be displayed so as to approach the target color temperature set by the setting unit 302.

[3-2. Operation]
The operation of the signal processing apparatus configured as described above will be described below.

[3-2-1. Operation of the setting unit]
The setting unit 302 sets the target color temperature of the content data according to the first ratio and the second ratio calculated by the calculation unit 101. At this time, the color temperature is set lower as the first ratio of the first region in the content data is larger. Furthermore, the setting unit 302 sets a target color temperature between the color temperature set according to the first ratio and the second ratio calculated by the calculation unit 101 and the color temperature of the ambient light detected by the detection unit 300. Set.

  FIG. 13 is a diagram showing an example of color temperature setting in the present embodiment.

  In FIG. 13, the horizontal axis represents time, and the vertical axis represents color temperature. In FIG. 13, K1 is a color temperature set by the setting unit 302 according to the first ratio and the second ratio calculated by the setting unit 101. K2 is the color temperature of the surrounding environment detected by the detection unit 300. K3 is a target color temperature set between the color temperature K1 and the color temperature K2.

  As shown in FIG. 13, the color temperature K3 is set to a color temperature between the color temperature K1 and the color temperature K2.

[3-3. Effect]
As described above, in the present embodiment, the setting unit 302 uses the color temperature set according to the first ratio and the second ratio calculated by the calculation unit 101 and the color of the ambient light detected by the detection unit 300. Set the target color temperature between the temperature. The conversion unit 103 converts the color temperature of the content data displayed at the target color temperature.

  Thus, the color temperature set by the first ratio of the first area of the content data to the display area and the second ratio of the second area to the display area, and the color temperature of the ambient light using the signal processing device The target color temperature can be set to the color temperature between the two even when there is a large difference between the two. Therefore, the user's uncomfortable feeling caused by the difference between the color temperature set in the display unit 105 and the color temperature of the ambient environment light can be suppressed.

  As described above, the embodiments have been described as examples of the technology in the present disclosure. For this purpose, the accompanying drawings and detailed description are provided.

  Accordingly, among the components described in the accompanying drawings and the detailed description, not only the components essential for solving the problem, but also the components not essential for solving the problem in order to illustrate the above technique. May also be included. Therefore, it should not be immediately recognized that these non-essential components are essential as those non-essential components are described in the accompanying drawings and detailed description.

  Moreover, since the above-mentioned embodiment is for demonstrating the technique in this indication, a various change, replacement, addition, abbreviation, etc. can be performed in a claim or its equivalent range.

  The present disclosure is applicable to a signal processing device with a display unit. Specifically, the present disclosure is applicable to PC displays, in-flight displays, tablet terminals, head mounted displays, smartphones, and the like.

1, 2, 3 Display device 10, 20, 30 Signal processing device 100 Acquisition unit 101 Calculation unit 102, 202, 302 Setting unit 103, 203 Conversion unit 104 Display control unit 105 Display unit 300 Detection unit

Claims (7)

  The display area of the content data is divided into a plurality of areas, and a first ratio of the first area in which the characters are mainly displayed in the display area to the display area, and the display area in which the characters other than the characters are mainly displayed. A calculation unit that calculates a second ratio of each of the two regions to the display region, a setting unit that sets a target color temperature of the content data based on the first ratio and the second ratio, And a conversion unit that changes the color temperature of the content data to the target color temperature.   The signal processing apparatus according to claim 1, wherein the setting unit sets a lower color temperature as a target color temperature as the first ratio increases.   2. The signal processing apparatus according to claim 1, wherein the calculation unit does not set a region where a saturation of a background color is a predetermined value or more in the first region as the first region.   When the setting unit calculates the target color temperature of the content data to be displayed next, the setting unit currently displays the color temperature between the target color temperature of the currently displayed content data and the target color temperature of the content data to be displayed next The signal processing device according to claim 1, wherein the signal processing device is set as a target color temperature of content data therein. It has a detector that detects the color temperature of ambient ambient light,
The setting unit sets a color temperature between a color temperature detected by the detection unit and a color temperature set according to the first ratio and the second ratio calculated by the calculation unit as a target color temperature. The signal processing apparatus according to claim 1.   The display area of the content data is divided into a plurality of areas, and a first ratio of the first area in which the characters are mainly displayed in the display area to the display area, and the display area in which the characters other than the characters are mainly displayed. A calculation unit that calculates a second ratio of each of the two regions to the display region, and a conversion unit that changes a current color temperature in the content data to a target color temperature. A signal processing apparatus having a color temperature depending on a ratio between one area and the second area.   The display area of the content data is divided into a plurality of areas, and a first ratio of the first area in which the characters are mainly displayed in the display area to the display area, and the display area in which the characters other than the characters are mainly displayed. A second ratio of each of the two areas to the display area is calculated, a target color temperature of the content data is set based on the first ratio and the second ratio, and a current color in the content data is set. A signal processing method for finally changing the temperature to the set target color temperature.

Images