Patent ID: 7139436

Claim:
An orthogonal transform apparatus operable to perform one of an N-by-N orthogonal transformation and an N/2-by-N/2 orthogonal transformation on data on an N-pixels-by-N-lines-formed pixel block, where N is equal to 2x, and x is an exponent, said orthogonal transform apparatus comprising: an input unit operable to enter N-pieces of pixel data after receipt of the N-pieces of pixel data in an N-by-N orthogonal transform mode, and said input unit operable to enter N/2-pieces of first pixel data and N/2 pieces of second pixel data after receipt of the N-pieces of pixel data in an N/2-by-N/2 orthogonal transform mode; and an orthogonal transform operation unit operable to, in the N-by-N orthogonal transform mode, perform an operation on the entered N-pieces of pixel data and given N-by-N orthogonal transformation-related coefficient data, thereby producing N-number of orthogonal transform coefficients, said orthogonal transform operation unit operable to, in the N/2-by-N/2 orthogonal transform mode, perform an operation on the entered N/2-pieces of first pixel data and given N/2-by-N/2 orthogonal transformation-related coefficient data, thereby producing a first N/2-number of orthogonal transform coefficients, and said orthogonal transform operation unit operable to, in the N/2-by-N/2 orthogonal transform mode, perform an operation on the entered N/2-pieces of second pixel data and the given N/2-by-N/2 orthogonal transformation-related coefficient data, thereby producing a second N/2-number of orthogonal transform coefficients.