Page 129 - DSP Integrated Circuits

114 Chapters Digital Signal Processing

3.31 Show that transposition of the intermediate array can be accomplished in the
DCT processor by appropriately writing and reading the intermediate values.
3.32 A 1024-point FFT is computed for a digital signal obtained from a CD player.
What is the frequency resolution?

3.33 Wang [44] classified the following DCT kernels for N = power of 2:

where

(a) Compare the four transforms with the ones previously defined.
(b) Find the inverse transforms.

DESIGN PROJECTS

JPEG
Desktop publishing, graphic arts, color facsimile, and medical imaging are some
new applications that require efficient compression of images. An international
standard for compression of digital grayscale and color images has been estab-
lished by JPEG. The discrete cosine transform is a key algorithm in this compres-
sion scheme.
Analyze the algorithms that are used, develop a functional description, and
draw the corresponding block diagrams for the scheme used in the still picture
JPEG coder-decoder. Determine also a functional specification that can be used
for the design of an ASIC. Compare your findings with the performance of the
CL550 coprocessor from C-Cube Microsystems Inc. See ISO/IEC JTC11 Draft
Intern. Standard 10918-1, Nov. 1991, and 10918-2, Dec. 1991.

Adaptive Filter
Develop in parallel to the FFT case study an implementation of the adaptive filter
described in sections 3.14.1 and 3.14.2. Define an appropriate specification for a
typical application or select for the sake of simplicity the internal data word
length to 16 bits, N = 10, and /"sample = 32 kHz. This abbreviation should not be
confused with LSI (large scale integration).