A signal processing device comprising: a conversion unit configured to convert a dynamic range of an image signal to be output to an output device in dependence upon output device information, the output device information indicative of a dynamic range capability and a type of the output device, wherein for output device information indicating that the output device connected to the signal processing device is a non-display type of output device, the conversion unit is configured to prohibit conversion of the dynamic range of the image signal; and a transmission unit configured to transmit the image signal output by the conversion unit to the output device, wherein, for output device information indicating that the output device is a display type of output device, the conversion unit is configured to convert the dynamic range of the image signal depending on the dynamic range capability of the output device, wherein the conversion unit is configured to convert a High Dynamic Range image signal into a Standard Dynamic Range image signal, wherein for output device information indicating that the output device connected to the signal processing device is the non-display type of output device and is compatible with HDR image signals the transmission unit is configured to transmit the image signal output by the conversion unit to the output device and to transmit an HDR InfoFrame to the output device, and wherein for output device information indicating that the output device connected to the signal processing device is the non-display type of output device and is not compatible with HDR image signals the transmission unit is configured to transmit the image signal output by the conversion unit to the output device without transmitting the HDR InfoFrame. a conversion unit configured to convert a dynamic range of an image signal to be output to an output device in dependence upon output device information, the output device information indicative of a dynamic range capability and a type of the output device, wherein for output device information indicating that the output device connected to the signal processing device is a non-display type of output device, the conversion unit is configured to prohibit conversion of the dynamic range of the image signal; and a transmission unit configured to transmit the image signal output by the conversion unit to the output device, wherein, for output device information indicating that the output device is a display type of output device, the conversion unit is configured to convert the dynamic range of the image signal depending on the dynamic range capability of the output device, wherein the conversion unit is configured to convert a High Dynamic Range image signal into a Standard Dynamic Range image signal, wherein for output device information indicating that the output device connected to the signal processing device is the non-display type of output device and is compatible with HDR image signals the transmission unit is configured to transmit the image signal output by the conversion unit to the output device and to transmit an HDR InfoFrame to the output device, and wherein for output device information indicating that the output device connected to the signal processing device is the non-display type of output device and is not compatible with HDR image signals the transmission unit is configured to transmit the image signal output by the conversion unit to the output device without transmitting the HDR InfoFrame.