Transmitting apparatus, transmitting method, receiving apparatus, and receiving method

A receiver, comprising:

• circuitry configured to:
• receive transmission image data and a control message via broadcast or network, the transmission image data being generated by applying a predetermined opto-electrical transfer function to input image data of a high dynamic range image, and the control message including a first mapping threshold;
• generate converted image data based on the received transmission image data by
• performing a first conversion on a luminance level within a sub-region of an image represented by the transmission image data when the luminance level is not greater than the first mapping threshold, and
• performing a second conversion on the luminance level within the sub-region of the image when the luminance level is greater than the first mapping threshold;
• and
• display a converted image on a display according to the converted image data.

A receiving method, comprising:

• receiving transmission image data and a control message via broadcast or network, the transmission image data being generated by applying a predetermined opto-electrical transfer function to input image data of a high dynamic range image, and the control message including a first mapping threshold;
• generating, by circuitry of a receiving device, converted image data based on the received transmission image data, including
• performing a first conversion on a luminance level within a sub-region of an image represented by the transmission image data when the luminance level is not greater than the first mapping threshold, and
• performing a second conversion on the luminance level within the sub-region of the image when the luminance level is greater than the first mapping threshold;
• and
• displaying a converted image on a display according to the converted image data.

A transmitter, comprising:

• circuitry configured to:
• apply a predetermined opto-electrical transfer function to input image data of a high dynamic range image to obtain transmission image data;
• generate a control message that includes a first mapping threshold for a sub-region of an image represented by the transmission image data, a luminance level within the sub-region of the image is
• subject to a first conversion processed by a receiver when the luminance level is not greater than the first mapping threshold, and
• subject to a second conversion processed by the receiver when the luminance level is greater than the first mapping threshold;
• and
• transmit the transmission image data and the control message to the receiver.

A transmitting method, comprising:

• applying a predetermined opto-electrical transfer function to input image data of a high dynamic range image to obtain transmission image data;
• generating, by circuitry of a transmitter, a control message that includes a first mapping threshold for a sub-region of an image represented by the transmission image data, a luminance level within the sub-region of the image is
• subject to a first conversion processed by a receiver when the luminance level is not greater than the first mapping threshold, and
• subject to a second conversion processed by the receiver when the luminance level is greater than the first mapping threshold;
• and
• transmitting, by the circuitry, the transmission image data and the control message to the receiver.