An image formation method for forming a color image by imagewise exposing a color negative type silver halide photographic material comprising a transparent support having provided thereon at least three kinds of light-sensitive layers, followed by development processing at a temperature of 50.degree. C. or more, which comprises the steps of reading with an imaging apparatus an image obtained from the color negative type silver halide photographic material whose sensitivity and gradient satisfy the following relationship, applying digital image processing thereto, and then, obtaining output signals of three or more colors: [equation included] [equation included]
wherein S represents an ISO sensitivity, and .gamma. represents an average gradient of the three kinds of light-sensitive layers, thereby inviting no failure in shooting due to insufficient exposure in a compact camera or a film with lens, and forming a color image of high quality.