1. A display apparatus with an image-capturing function, comprising: an image-capturing unit; an outputting unit configured to output an image signal of an image captured using the image-capturing unit to an external apparatus; an inputting unit configured to input a combined image generated by an image combining unit configured to combine an external input image with an image captured using the image-capturing unit from the external apparatus; a display unit; a corrector configured to perform image-capture-distortion correction and display-distortion correction on an image signal of captured by the image-capturing unit; a controller configured to control the corrector to perform the image capture-distortion correction if a correction mode of the image capture-distortion is set, control the corrector to perform the display distortion correction if a correction mode of the display distortion is set, and control the corrector to perform the image capture-distortion correction and the display distortion correction at the same time if a correction mode of the image capture-distortion and the correction mode of the display-distortion are set; and a setting unit configured to set a type of distortion correction performed by the corrector and to determine whether or not the image combining unit is to perform image combining, wherein the controller performs the control according to the settings made by the setting unit, wherein the corrector performs the image-capture-distortion correction using a first correction table that contains image-capture-distortion correction data and performs the display-distortion correction using a second correction table that contains display-distortion correction data, and wherein when the image combining unit performs image combining to generate the combined image, the corrector performs image-capture inverse distortion correction on the external input image by applying distortion equal to image-capture distortion caused by the image-capturing unit, and the corrector performs image-capture-distortion correction and display-distortion correction on the combined image.