Image formation method and apparatus for printing images using reduced amount of developer

An image formation apparatus comprising:

• a memory configured to store image data including objects each having information on a type and densities of colors of the object;
• a developer-remaining-amount sensor configured to sense and output remaining-amount information indicating a color of a developer having a small remaining amount among colors of respective developers for image formation;
• a controller configured to transform first pixel values of the densities of the colors of each object included in the image data stored in the memory into second pixel values indicating use amounts of the colors of the developers, for each object based on a type of the object and the remaining-amount information;
• and
• an image formation unit configured to form images on a recording medium for the objects included in the image data by using the developers in accordance with use amounts of the developers corresponding to the second pixel values transformed by the controller,
• wherein the controller includes:
• an object extraction unit configured to extract the type of each of the object included in the image data stored in the memory;
• a pixel-transformation-matrix generator configured to generate a pixel transformation matrix for each object based on the type and the remaining-amount information, the pixel transformation matrix being for transforming the first pixel values into the second pixel values;
• and
• a pixel-value transformer configured to transform the first pixel values of each object into the second pixel values based on the pixel transformation matrix,
• wherein the object each have an identification number, and
• wherein the object extraction unit is configured to extract from the image data stored in the memory, the identification number of each object having the first pixel values and the type of the object based on the identification number.

An image formation apparatus comprising:

• a memory configured to store image data including objects each having information on a type and densities of colors of the object;
• an object extraction unit configured to extract each of the objects included in the image data stored in the memory and the type of the object including first pixel values indicating the densities of the colors of the object;
• and
• a pixel-value transformer configured to transform the first pixel values of the type of each object extracted by the object extraction unit into second pixel values indicating use amounts of the colors of the developers, based on remaining-amount information indicating a color of a developer having a small remaining amount among the colors of the developers, wherein
• as objects whose images are to be formed by using the use amounts of the developers corresponding to the second pixel values transformed by the pixel-value transformer, a text object and at least one type of image object different from the text object are extracted by the object extraction unit
• the pixel-value transformer is configured to set a reduction amount by transformation of the first pixel value into the second pixel value of the color of the developer having the small remaining amount in such a manner that the reduction amount for the text object is smaller than the reduction amount for the image object, wherein the small remaining amount equals the second pixel value minus the first pixel value.