Image rotation assist circuitry and method

A method for rotating a digital image, comprising the steps of:

• generating, prior to receiving a plurality of image blocks from an image processor, a set of precalculated values in response to a request for rotation of the digital image, each of the image blocks comprising a plurality of sub-blocks, the precalculated values being based on at least one of a predetermined rotation angle, an image block size, horizontal and vertical digital image dimensions and a memory module dimension;
• rotating each of the plurality of image blocks through the predetermined rotation angle to generate a plurality of rotated image blocks;
• performing only additive operations on at least two values in the set of precalculated values to determine a destination address for each of the sub-blocks;
• and
• storing each of the sub-blocks in a memory module at the destination address.

An apparatus for rotating a digital image comprising:

• an input module for receiving a digital image to be rotated;
• an image processor electrically coupled to the input module for generating a plurality of image blocks to be rotated from the digital image and rotating the image blocks through a predetermined rotation angle, each of the image blocks comprising a plurality of sub-blocks;
• a value processor for generating a set of precalculated values in response to a request for rotation of the digital image based on at least one of the predetermined rotation angle, an image block size, horizontal and vertical digital image dimensions and a memory module dimension;
• a rotation assist module electrically coupled to the image processor and the value processor and having an output, the rotation assist module receiving the set of precalculated values from the value processor prior to receiving the rotated image blocks from the image processor, the rotation assist module performing only additive operations on at least two values in the set of precalculated values to determine a destination address for each sub-block;
• and
• a memory module electrically coupled to the output of the rotation assist module for storage of each of the sub-blocks at each corresponding destination address.