An image coding process and notion detecting process using bidirectional prediction

An image processing apparatus comprising:

• a) absolute difference value calculating means for calculating an absolute difference value of each pixel between image data of first and second fields constituting a frame image;
• b) first comparison means for comparing the absolute difference value calculated by said absolute difference value calculating means with a first threshold value;
• c) calculation means for calculating a sum total of comparison results of said first comparison means;
• and
• d) judging means for judging a field correlation of said image data between the first and second fields in accordance with the sum total calculated by said calculation means.

An image processing apparatus comprising:

• a) absolute difference value calculating means for calculating an absolute difference value of each pixel between image data of first and second fields constituting a frame image;
• b) first comparison means for comparing the absolute difference value calculated by said absolute difference value calculating means with a first threshold value;
• c) count means for counting comparison results of said first comparison means;
• and
• d) judging means for judging a field correlation of said image data between the first and second fields in accordance with a count value of said count means.

An image processing method capable of coding image data through bidirectional prediction, comprising:

• a) a first storage step of storing a reference image in a forward direction in a first memory area;
• b) a first motion vector detecting step of detecting a motion vector by reading image data stored in said first memory area;
• c) a second storage step of storing a reference image in a backward direction in a second memory area;
• d) a third storage step of storing a reference image in a forward direction in an expanded range, in a third memory area;
• e) a second motion vector detecting step of detecting a motion vector by reading image data stored in said second or third memory area;
• and
• f) a coding step of coding, through motion compensation prediction, input image data by using a motion vector detected by said first or second motion vector detecting step.

An image processing method comprising:

• a) an absolute difference value calculating step of calculating an absolute difference value of each pixel between image data of first and second fields constituting a frame image;
• b) a first comparison step of comparing the absolute difference value calculated by at absolute difference value calculating step with a first threshold value;
• c) a calculation step of calculating a sum total of comparison results obtained at said first comparison step;
• and
• d) a judging step of judging a field correlation of said image data between the first and second fields in accordance with the sum total calculated at said calculation step.

An image processing method comprising:

• a) an absolute difference value calculating step of calculating an absolute difference value of each pixel between image data of first and second fields constituting a frame image;
• b) a first comparison step of comparing the absolute difference value calculated at said absolute difference value calculating step with a first threshold value;
• c) a count step of counting comparison results obtained at said first comparison step;
• and
• d) a judging step of judging a field correlation of said image data between the first and second fields in accordance with a count value obtained at said count step.

An image processing apparatus capable of coding image data through bidirectional prediction, comprising:

• a) storage means for storing a reference image in a forward direction, in a first memory area, a reference image in a backward direction, in a second memory area, and a reference image in a forward direction in an expanded range, in a third memory area;
• b) first motion vector detecting means for detecting a motion vector by reading image data stored in said first memory area;
• c) second motion vector detecting means for detecting a motion vector by reading image data stored in said second or third memory area;
• and
• d) coding means for coding, through motion compensation prediction, input image data by using a motion vector detected by said first or second motion vector detecting means.

An image processing method capable of coding image data through bidirectional prediction, comprising:

• a) a storage step of storing a reference image in a forward direction, in a first memory area, a reference image in a backward direction, in a second memory area, and a reference image in a forward direction in an expanded range, in a third memory area;
• b) a first motion vector detecting step of detecting a motion vector by reading image data stored in said first memory area;
• c) a second motion vector detecting step of detecting a motion vector by reading image data stored in said second or third memory area;
• and
• d) a coding step of coding, through motion compensation prediction, input image data by using a motion vector detected at said first or second motion vector detecting step.