Haar wavelet transform embedded lossless type IV discrete cosine transform
A shared lossless Haar transform and an appended type-IV discrete cosine transform are combined to form a lossless discrete cosine type-IV transform having a fast pipeline architecture for providing fast reversible lossless DCT-IV transform data.
1. A transform for transforming input data into DCT transformed data, the transform useful for transforming the Haar transform input data into the DCT-IV transform data for communicating the Haar transform data in a transform domain over a communication data link, the transform comprising,
a latch for latching and permuting the Haar transform input data comprising words five, six, seven, eight, one, two, three, and four respectively into latched words one, three, two, four, five, seven, six, eight,
a processor for DCT-IV block transforming the latched words one, two, three, four, five, six, seven, and eight, into processed words one, two, three, four, five, six, seven, and eight, and
four process units, the four process units are rotators for providing DCT-IV transform data, a first rotator rotating processed words one and two by π/32 radians into words one and two of the DCT-IV transform data, a second rotator rotating processed words eight and three by π/16 radians into words three and four of the DCT-IV transform data, a third rotator rotating processed words seven and four by 3π/32 radians into words five and six of the DCT-IV transform data, a fourth rotator rotating processed words six and five by π/8 radians into words seven and eight of the DCT-IV transform data.
2. The transform of claim 1 wherein,
each of the four process units is a 2×2 rotator having two bit-parallel serial word inputs X 1 and X 2 that are rotated by an angle θ in radians into two outputs Y 1 and Y 2 where Y 1 =cos θX 1 =sin θX 2 and Y 2 =cos θX 1 +sin θX 2 .
3. The transform of claim 1 wherein,
each of the four process units is a three stage lifting transform.
4. A system for transforming input data into DCT-IV transform data, the system useful for transforming the input data into DCT-IV transform data for communicating the input data in a transform domain over a communication data link, the system comprising,
a shared Haar transform for transforming the input data into Haar transformed data, and
a DCT-IV appended transform for transforming the Haar transformed data into the DCT-IV transform data, the DCT-IV transform data is reversible into the input data as lossless transform data when the DCT-IV transform data is inversely transform by the DCT-IV appended transform and the shared Haar transform.
5. The system of claim 4 wherein,
each of the four process units is a three stage lifting transform.
6. The system of claim 4 wherein,
the input data is eight words,
the DCT-IV transform data is eight words.
7. The system of claim 4 wherein the DCT-IV appended transform comprises,
a latch for latching and permuting the Haar transform data into latched data,
a block processor for processing the latched data into processed data, and
four process units for rotating the process data into the DCT-IV transform data.
8. The system of claim 7 wherein,
the latched data is latched data words,
the block processor comprises three cascaded DCT-IV transforms, and
the block processor operates on half words of the latched data words.
9. The system of claim 4 wherein the DCT-IV appended transform comprises,
a latch for latching and permuting the Haar transform input data comprising words five, six, seven, eight, one, two, three, and four respectively into latched words one, three, two, four, five, seven, six, eight,
a processor for DCT-IV block transforming the latched words one, two, three, four, five, six, seven, and eight, into processed words one, two, three, four, five, six, seven, and eight, and
four process units are four rotators for rotating processed words, a first rotator rotating processed words one and two by π/32 radians into DCT-IV transform data words one and two, a second rotator rotating processed words eight and three by π/16 radians into DCT-IV transform data words three and four, a third rotator rotating processed words seven and four by 3π/32 radians into DCT-IV transform data words five and six, a fourth rotator rotating processed words six and five by π/8 radians into DCT-IV transform data words seven and eight.