Image rotation method and image rotation processing apparatus

An image rotation processing apparatus which rotates an M.times.N image, said apparatus comprising:

• a first accumulator circuit for accumulating the cosine value corresponding to a rotation angle .theta. of the unit value of the coordinate value x;
• a second accumulator circuit for accumulating the sine value corresponding to the rotation angle .theta. of the unit value of the coordinate value x;
• a third accumulator circuit for adding the negative sine value corresponding to the rotation angle .theta. of the unit value of the coordinate value y to an output of said first accumulator circuit, and summing the negative sine value with the added value to determine the value of the rotated coordinate x';
• and
• a fourth accumulator circuit for adding the cosine value corresponding to the rotation angle .theta. of the unit value of the coordinate value y to an output value of said second accumulator circuit and summing the cosine value with the added value to determine the value of the rotated coordinate y'.

An image rotation processing circuit which rotates on M.times.N image through a rotation angle .theta., said circuit comprising:

• a first adder having first and second inputs and an output;
• a first register connected to the output of said adder which stores the output from said first adder;
• means for supplying a cosine value (n) of the rotation angle .theta. as the first input to said first adder;
• feedback means interconnecting said first register and said adder for supplying the contents of said first register as the second input to said first adder;
• a first transmitting gate connected to said first adder which transmits the output of said first adder;
• a second adder having first and second inputs and an output;
• means for supplying a negative sine value (-m) of the rotation angle .theta. to the adder as the first input;
• a second register connected to said first transmission gate and the output of said second adder;
• feedback means interconnecting said second adder and said second register for supplying the contents of said second register as the second input to said second adder;
• a second transmitting gate connected to said second adder which transmits the output of said second adder responsive to a control signal to produce a rotational coordinate x';
• a third adder having first and second inputs and an output;
• a third register connected to the output of said adder which stores the output from said third adder;
• means for supplying a sine value (m) of the rotation angle .theta. as the first input to said third adder;
• feedback means interconnecting said third register and said third adder for supplying the contents of said third register as the second input to said third adder;
• a third transmitting gate connected to said third adder which transmits the output of said third adder;
• a fourth adder having first and second inputs and an output;
• means for supplying the negative sine value (-m) to the adder as the first input;
• a fourth register connected to said first transmission gate and the output of said fourth adder;
• feedback means interconnecting said fourth adder and said fourth register for supplying the contents of said fourth register as the second input to said fourth adder;
• a fourth transmitting gate connected to said fourth adder which transmits the output of said fourth adder responsive to a second control signal to produce a rotational coordinate y'.