1. 02/11/05ENEE408G Spring 2005 Multimedia Signal Processing 1 ENEE408G: Capstone Design Project: Multimedia Signal Processing Design Project 1: Image Processing and Digital Photography

2. 02/11/05ENEE408G Spring 2005 Multimedia Signal Processing 2 Outline JPEC-like Codec Matlab Assignment – Common Mistakes Matlab Programming Tasks Announcement

3. 02/11/05ENEE408G Spring 2005 Multimedia Signal Processing 3 JPEC-like Codec - Encoder At beginning of the encoder: !del JPEG_Y.jpg JPEG_Cb.jpg JPEG_Cr.jpg Apply: JPEG_entropy_encode.m three times After each use: !rename JPEG.jpg JPEG_x.jpg

4. 02/11/05ENEE408G Spring 2005 Multimedia Signal Processing 4 JPEC-like Codec - Decoder Apply: JPEG_entropy_decode.m three times Before each use: !rename JPEG_x.jpg JPEG.jpg JPEC-like Codec - Demo

5. 02/11/05ENEE408G Spring 2005 Multimedia Signal Processing 5 Matlab Assignment – Common Mistakes Wrong Names: ENEE408G-Assign1, 408G-Assign1 Problem 1: Use 8 bits to quantize the hidden message Z Z = Z/power(2, 8-1) – 1; sound(Z, fs, 8); Initialize Z before using for loop Z = zeros(1, N/8); or Z= zeros(N/8,1);

6. 02/11/05ENEE408G Spring 2005 Multimedia Signal Processing 6 Matlab Assignment – Common Mistakes Problem 2 and 3: Convert uint8 (unsigned 8-bit integers) to double (double-precision) Im = imread(‘Girl.bmp’); Im = double(Im); Im = double(imread(‘Girl.bmp’)); Initialize before using for loop for summation [H,W] = size(Im); Im_new = zeros(H,W); Im_new = zeros(size(Im)); Work on the whole array (vectors, matrices,…) instead of on the individuals (elements).

7. 02/11/05ENEE408G Spring 2005 Multimedia Signal Processing 7 Matlab Programming Tasks Two types of Matlab programs: function or script Scripts do not accept input arguments or return output arguments. They operate on data in the workspace. Functions can accept input arguments and return output arguments. Internal variables are local to the function. Example: Im = imread(‘Girl.bmp’); Should write functions for Matlab programming tasks JPEC_encoder(filename, blk_size, comp_factor)

8. 02/11/05ENEE408G Spring 2005 Multimedia Signal Processing 8 Matlab Programming Tasks A clear program structure with components: Show the understanding about the implemented system Easy to integrate the components together between group members Example: In JPEC_encoder.m Member1: ImY_DCT = DCT_transformer(ImY, N); Member1: ImY_Q = quantizer(ImY_DCT, N, comp_factor);

9. 02/11/05ENEE408G Spring 2005 Multimedia Signal Processing 9 Announcement Office Hours: Time: 5pm – 7pm on Thursdays Place : Jasmine Lab Design project 1 [I] Report: Submit to your group’s folder in ECELABS File server Deadline: 02/18 (next Friday). 8:45am for section 0102 and 12:45pm for section 0101

10. 02/11/05ENEE408G Spring 2005 Multimedia Signal Processing 10 Announcement Next Friday (02/18/2005) Check in : Digital Camera, Pocket PC Bring your own microphone, earphone, and converter. Today: Test your Pocket PC programs for the current projects. Useful Link VcDemo: Image and Video Compression Tool http://www-ict.its.tudelft.nl/~inald/vcdemo/ Wotsit’s Multimedia Format Resource http://www.wotsit.org/