1. Image and Sound Editing
Raed S. Rasheed
2012

2. Digital Sound Pitch digital sound Echo digital sound
Fade in digital sound
Fade out digital sound

3. Pitch digital sound
Is the process of changing the speed or duration of an audio signal. The simplest way to change the duration or pitch of a digital audio clip is to resample it. This is a mathematical operation that effectively rebuilds a continuous waveform from its samples and then samples that waveform again at a different rate. When the new samples are played at the original sampling frequency, the audio clip sounds faster or slower

4. Pitch digital sound

5. Pitch digital sound
ALGORITHM Sound_Pitch INPUT Sound, rate 02 OUTPUT NewSound 03 BEGIN 04 Create new sound file NewSound; 05 SET index = 0, c = 0; 06 WHILE index < Sound.Length 07 SET i = tranc(index); 08 SET frac = index - i; 09 SET S1 = Sound[i]; 10 SET S2 = Sound[i+1]; 11 SET NewSound[c] = S1 + ( S2 – S1) * frac; 12 SET c = c+1; 13 SET index = index + rate; 14 END WHILE 15 RETURN NewSound; 16 END

6. Echo (Reverb ) digital sound
is the persistence of sound in a particular space after the original sound is produced. A reverberation, or reverb, is created when a sound is produced in an enclosed space causing a large number of echoes to build up and then slowly decay as the sound is absorbed by the walls and air.

7. Echo (Reverb ) digital sound

8. Echo (Reverb ) digital sound
ALGORITHM Sound_Echo INPUT Sound, delay, decay 02 OUTPUT NewSound 03 BEGIN 04 SET delaySample = delay; 05 SET i = 0; 06 WHILE i < Sound.Length 07 IF i < delaySample THEN 08 SET NewSound[i] = Sound[i]; 09 ELSE 10 SET NewSound[i] = Sound[i] + Sound[i - delaySample] * decay; 11 END IF 12 SET i = i + 1; 13 END WHILE 14 RETURN NewSound; 15 END

9. Fade in digital sound
ALGORITHM Sound_FadeIn INPUT Sound 02 OUTPUT NewSound 03 BEGIN 04 SET decayRate = 1 / Sound.Length; 05 SET decay = 0; 06 SET i = 0; 07 WHILE i < Sound.Length 08 SET NewSound[i] = Sound[i] * decay; 09 SET i = i + 1; 10 SET decay = decay + decayRate; 11 END WHILE 12 RETURN NewSound; 13 END

10. Fade out digital sound
ALGORITHM Sound_FadeOut INPUT Sound 02 OUTPUT NewSound 03 BEGIN 04 SET decayRate = 1 / Sound.Length; 05 SET decay = 1; 06 SET i = 0; 07 WHILE i < Sound.Length 08 SET NewSound[i] = Sound[i] * decay; 09 SET i = i + 1; 10 SET decay = decay - decayRate; 11 END WHILE 12 RETURN NewSound; 13 END