Noble metal image forming method

A method for producing an image comprising, forming a silver image on a photographic material which comprises a glass substrate having thereon at least one silver halide emulsion layer having a binder comprising at least one material selected from the group consisting of gelatin, colloidal albumin, casein, a cellulose derivative, a saccharide derivative, a synthetic hydrophilic colloid, a modified gelatin, a gelatin derivative, or a synthetic high molecular weight material, either directly or on at least one subbing layer on the substrate, by (1) imagewise exposing and developing said photographic material, (2) replacing said silver image with a noble metal image by contacting said silver image with a toning solution containing a compound containing a noble metal having an ionization tendency smaller than the ionization tendency of silver to form a mixed image of a silver compound and said noble metal, said noble metal being selected from the group consisting of gold, platinum, palladium, rhodium, iridium and ruthenium, and (3) then subsequently heating after toning the photographic material in an oxygen-containing gas to a temperature between about 350.degree. to 600.degree. C for a period sufficient to thermally decompose and substantially remove the organic components on the substrate.