1. An image signal processing device which performs a predetermined signal process on original image data supplied from an image sensor, comprising: a sensor controller that controls an operation of the image sensor by a plurality of photographing modes, and generates and outputs a control signal that controls photographic attributes corresponding to at least one of the plurality of photographing modes that are predetermined in a candidate image presenting mode or one selected by a user; a frame image generating unit that generates a plurality of frame image data by processing the original image data sequentially input from the image sensor by frames; a frame memory that stores the plurality of frame image data; a thumbnail image generating unit that generates a plurality of thumbnail image data by respectively scaling the plurality of frame image data, at least one of the plurality of frame image data being encoded to create at least one of the plurality of thumbnail image data in a compressed format for output; an output unit that firstly outputs the plurality of thumbnail image data and reads and secondly outputs a frame image data corresponding to a thumbnail image data, which is selected on the basis of a user's selection signal out of the plurality of thumbnail image data, from the frame memory; and a multimedia processor that determines whether the frame image data output by the user's selection signal is in the compressed format and, in response to determining that the frame image data output by the user's selection signal is not in the compressed format, encodes the frame image data upon the user's selection signal to output in the compressed format, while storing the frame image data without further encoding in response to determining that the frame image data is in the compressed format, wherein the original image data are sequentially generated by causing the image sensor to apply different photographing attributes by the frames on the basis of a sensor control signal input from the image signal processing device, and wherein the thumbnail image generating unit determines one or more thumbnail attributes of an arrangement order and a size of the plurality of thumbnail images on the basis of an image analysis information.