An image processing device comprising: an input unit configured to receive frame image data from an imaging device that images a subject and continuously outputs the frame image data; a storage unit configured to store a plurality of data formats corresponding to different image qualities, the data formats defining a format of at least two image quality elements among resolution, color representation, update period and gradation that are elements related to image quality of an image displayed on a display unit, the display unit continuously performing display processing on the frame image data and displaying the image, the storage unit being configured to store importance degree information indicating an order of the image quality elements according to an importance degree; an image processing unit configured to perform image processing on the frame image data input to the input unit according to the data format selected from the data formats stored in the storage unit; a wireless communication unit configured to transmit continuously wirelessly the frame image data subjected to the image processing by the image processing unit to the display unit; a detecting unit configured to detect a wireless communication environment when the wireless communication unit wirelessly transmits the frame image data; and a selection unit configured to select one of the data formats stored in the storage unit, the selection unit being configured to select the data format defining a combination of formats of the image quality element including a format lower in quality than a format defined in a currently selected data format for the element selected based on the importance degree information stored in the storage unit when deterioration of the communication environment is detected by the detection unit, wherein the storage unit is configured to store the importance degree information indicating an importance degree of the image quality elements, and store a plurality of data formats each of which corresponds to each user. an input unit configured to receive frame image data from an imaging device that images a subject and continuously outputs the frame image data; a storage unit configured to store a plurality of data formats corresponding to different image qualities, the data formats defining a format of at least two image quality elements among resolution, color representation, update period and gradation that are elements related to image quality of an image displayed on a display unit, the display unit continuously performing display processing on the frame image data and displaying the image, the storage unit being configured to store importance degree information indicating an order of the image quality elements according to an importance degree; an image processing unit configured to perform image processing on the frame image data input to the input unit according to the data format selected from the data formats stored in the storage unit; a wireless communication unit configured to transmit continuously wirelessly the frame image data subjected to the image processing by the image processing unit to the display unit; a detecting unit configured to detect a wireless communication environment when the wireless communication unit wirelessly transmits the frame image data; and a selection unit configured to select one of the data formats stored in the storage unit, the selection unit being configured to select the data format defining a combination of formats of the image quality element including a format lower in quality than a format defined in a currently selected data format for the element selected based on the importance degree information stored in the storage unit when deterioration of the communication environment is detected by the detection unit, wherein the storage unit is configured to store the importance degree information indicating an importance degree of the image quality elements, and store a plurality of data formats each of which corresponds to each user.