A process for forming an image which comprises heating a light-sensitive material comprising a support having thereon at least a light-sensitive silver halide, a binder and a dye-releasing redox compound which is reductive to the light-sensitive silver halide and which is capable of releasing a hydrophilic dye upon reaction with the light-sensitive silver halide on heating, after imagewise exposure or simultaneously with imagewise exposure, in a substantially water-free condition the dye-releasing redox compound being represented by the formula (I) wherein R represents a phenyl group having a hydroxy-substituted alkoxy group or an alkoxy-substituted alkoxy group at at least the 2-position thereof with respect to the diazo group and a group of the formula --SO.sub.2 NH--Y at the 5-position thereof with respect to the diazo group where Y represents a group capable of being oxidized silver halide to release a dye moiety including the --SO.sub.2 NH moiety.