Image forming apparatus and image forming method for adjusting heat applied during the fixing stage

An image forming apparatus that performs fixing processing on a sheet having a transferred toner image in smaller area units than the size of the sheet, the apparatus comprising:

• an input unit that inputs color image data;
• an image forming unit that performs color separation on color image data input by the input unit and forms a toner image in each of at least one predetermined color;
• a transfer unit that transfers the toner image in each color formed by the image forming unit over a sheet;
• a detecting unit that detects, for each of the areas, the maximum number of stacked toner images transferred within the area of the sheet having a transferred toner image in the each of the at least one predetermined color by the transfer unit;
• a determining unit that determines, for each of the areas, the amount of heat to be applied to the applicable area based on the maximum number of stacked toner images of the area detected by the detecting unit;
• and
• a fixing unit that, on each of the areas on the sheet after the transfer processing by the transfer unit, applies the amount of heat determined by the determining unit as the amount of heat to be applied to the area and fixes a transferred toner image in each color.