An image pickup apparatus includes: an image data production unit configured to produce data of a plurality of kinds of images from an image frame obtained by picking up an image of an object as a moving picture for each of pixel strings which configure a row; and an image sending unit configured to extract a pixel string in a region requested from a host terminal from within the data of each of the plurality of kinds of images and connect the pixel strings to each other for each unit number of pixels for connection determined on the basis of a given rule to produce a stream and then transmit the stream to the host terminal. The image sending unit switchably determines whether the unit number of pixels for connection is to be set to a fixed value or a variable value in response to the kind of each image.