Image interpolation apparatus and image interpolation method

An image interpolation apparatus which generates a single frame of color image data whose size is changed in magnification at least one of the horizontal direction and the vertical direction by using pixel data in a plurality of fields input in time-series order while switching a line reading method periodically, the image interpolation apparatus comprising:

• an index value computing section configured to extract discrete pixel data from the fields, select a plurality of groups of pixel data arranged in a specific direction from the pixel data in the vicinity of a position corresponding to the pixel position of the single frame of color image data in the extracted pixel data, and calculate an index value for the specific direction;
• a direction decision section configured to detect a direction in which there is a strong correlation in the pixel position on the basis of the index value calculated at the index value computing section;
• a switching section configured to select operation data used in operation for interpolation for each of a plurality of primary colors constituting the color image data from the field on the basis of which of the fields where the line reading method has been switched periodically a field to be interpolated at the change of magnification comes under and of the direction in which there is a strong correlation detected by the direction decision section and switch operation data;
• and
• an interpolation section configured to determine pixel data in the pixel position using the operation data switched by the switching section.

An image interpolation method which generates a single frame of image data interpolated using pixel data in a plurality of fields input in time-series order while switching a line reading method periodically, the image interpolation method comprising:

• an index value computing step of calculating an index value for a specific direction from a plurality of groups of pixel data arranged in the specific direction in the vicinity of a position in the field corresponding to the pixel position of the single frame of image data;
• a direction decision step of detecting a direction in which there is a strong correlation in the pixel position on the basis of the index value;
• a switching step of selecting operation data used in operation for interpolation from the field on the basis of which of the fields where the line reading method has been switched periodically a field to be interpolated comes under and of the direction in which there is a strong correlation and switching operation data;
• and
• an interpolation step of determining pixel data in the pixel position using the operation data.