To improve convenience in adjusting a development parameter.

A development processing device applies development processing to non-developed image data generated by a digital camera to produce developed image data. A first parameter group relating to a plurality of development parameters to be used for development processing is determined by a development parameter determination section, respectively. The development processing device includes a change screen display section for displaying a parameter change screen and the change screen display section displays on the parameter change screen a reference line, a plurality of number lines for a predetermined length with positions corresponding to the first parameter groups disposed on the reference line, and a plurality of marker images indicating, on the plurality of number lines, positions corresponding to a second parameter group changeable by a user on the number lines. On the basis of at least the second parameter group, a development processing section performs development processing.