Patent ID: 7675649

Claim:
An image forming apparatus for carrying out image forming in an electrophotography mode by processing a multi-valued image, the image forming apparatus comprising: a small domain generation section for generating, in the processed multi-valued image, a plurality of small domains each constituted of a plurality of pixels such that each of the plurality of pixels constituting the plurality of small domains is included as a pixel for subjection to toner quantity equivalent value calculation in only one of the plurality of small domains, so as to respectively convert pixels of the multi-valued image into count values relative to toner consumption quantity; a toner quantity equivalent value calculation section which converts gradation data of the pixel to be subjected to toner quantity equivalent value calculation into a toner quantity equivalent value, using (i) the gradation data of said pixel and (ii) the gradation data of at least one other pixel in the same small domain, and with reference to a previously-stored correlation between the gradation data of said at least one other pixel of the small domain and an actual toner consumption of the pixel subjected to toner quantity equivalent value calculation, the toner quantity equivalent value calculation section determining toner quantity equivalent values of all pixels of the multi-valued image based on the toner quantity equivalent value converted from the gradation data; a total toner quantity equivalent value calculation section for determining a total toner quantity equivalent value by accumulating the toner quantity equivalent values of the all pixels of the multi-valued image calculated by the toner quantity equivalent value calculation section; and a control section for setting conditions for process control when the total toner quantity equivalent value reaches a predetermined value.