Display apparatus and control method with images of different dynamic ranges

1. A display apparatus comprising:

a control circuit configured to switch to any one of a plurality of modes including a first mode capable of displaying an image of a first dynamic range on a display circuit and a second mode capable of displaying an image of a second dynamic range wider than the first dynamic range on a display circuit; and

a generating circuit configured to generate a partial image which includes at least a black region and is superimposed on an image displayed on the display circuit,

wherein the control circuit controls a luminance of the black region of the partial image in the second mode to be less than a luminance of the black region of the partial image in the first mode by changing a ratio of a gradation of the black region with respect to all gradations that can be displayed.

2. The apparatus according to claim 1 , wherein

the partial image includes character and/or graphic region,

the control unit controls the luminance of the character region in the second mode to be less than the luminance of the character region in the first mode.

3. The apparatus according to claim 2 , wherein the control unit changes a ratio of a gradation of the character and/or graphic region with respect to all the gradations that can be displayed.

4. The apparatus according to claim 3 , wherein the control unit controls the ratio of the luminance of the character and/or graphic region to the luminance of the black region in the second mode to be equal to or greater than the ratio of the luminance of the character and/or graphic region to the luminance of the black region in the first mode.

5. The apparatus according to claim 1 , wherein

the control unit is capable of changing a transmittance of the image including the black region,

the transmittance of the black region in the second mode is controlled to be smaller than the transmittance of the black region in the first mode.

6. The apparatus according to claim 1 , wherein the first dynamic range is SDR (Standard Dynamic Range),

the second dynamic range is High Dynamic Range.

7. A method of controlling a display apparatus comprising:

switching to any one of a plurality of modes including a first mode capable of displaying an image of a first dynamic range on a display unit and a second mode capable of displaying an image of a second dynamic range wider than the first dynamic range on the display unit;

generating a partial image which includes at least a black region and is superimposed on the image displayed on the display unit; and

controlling such that a luminance of the black region of the partial image in the second mode is less than a luminance of the black region of the partial image in the first mode by changing a ratio of a gradation of the black region with respect to all gradations that can be displayed.

8. A non-transitory computer-readable storage medium storing a program that causes a computer to execute a method of controlling a display apparatus comprising:

switching to any one of a plurality of modes including a first mode capable of displaying an image of a first dynamic range on a display unit and a second mode capable of displaying an image of a second dynamic range wider than the first dynamic range on the display unit;

generating a partial image which includes at least a black region and is superimposed on the image displayed on the display unit; and

controlling such that a luminance of the black region of the partial image in the second mode is less than a luminance of the black region of the partial image in the first mode by changing a ratio of a gradation of the black region with respect to all gradations that can be displayed.