Image processing apparatus using tonal degree conversion

A method for processing an image comprising the steps of:

• inputting image information and modification information for said image information;
• calculating a data quantity of modified image information, in accordance with said inputted image information and modification information;
• comparing a data quantity of said image information not modified with the data quantity calculated in said calculation step;
• and
• modifying said image information, wherein, if said comparison step indicates that the data quantity of said information not modified is larger, said image information is modified in accordance with said modification information and is stored in a buffer memory, and said modification information is overwritten, and wherein, if said comparison step indicates that the data quantity calculated in said calculating step is larger, said image information is stored in the buffer memory and said image information stored in said buffer memory is modified in accordance with said modification information and is stored in a frame memory.

An image processing method comprising the steps of:

• inputting image information and modification information representing a modification process to be performed on the image information;
• storing in a frame memory the image information modified on the basis of the modification information;
• determining whether or not the image information input in said inputting step is stored in the image area of a buffer memory without having been modified;
• storing the image information input in said inputting step in the image area of a buffer memory and for storing the modification information input in said inputting step in the image modification area of the buffer memory, when the determination obtained in said determining step is positive;
• storing in the image area of the buffer memory the image information obtained by modifying the image information input in said inputting step and storing information different from the modification information input in said inputting step in the image modification area of the buffer memory, when the determination obtained in said determining step is negative;
• and
• generating image information to be stored in the frame memory on the basis of the image information and the modification information stored in the buffer memory.

An image processing apparatus comprising:

• means for inputting image information and modification information representing a modification process to be performed on the image information;
• and
• a frame memory for storing the image information modified on the basis of the modification information,
• wherein said apparatus further comprises:
• a buffer memory having an image area for storing the image information and an image modification area for storing the modification information;
• means for determining whether or not the image information input by said input means is stored in the image area of said buffer memory without having been modified;
• means for storing the image information input by said input means in the image area of said buffer memory and for storing the modification information input by said input means in the image modification area of said buffer memory, when the determination by the determining means is positive;
• means for storing in the image area of said buffer memory the image information obtained by modifying the image information input by said input means and for storing information different from the modification information input by said input means in the image modification area of said buffer memory, when the determination by said determining means is negative;
• and
• process means for generating image information to be stored in said frame memory on the basis of the image information and the modification information stored in the buffer memory.