DIGITAL SIGNAL PROCESSING SUBMITTED BY:- KARAN KUMAR
Contents .What is DSP? . What is DSP used for? Speech & Audio processing Image & Video processing Adaptive filtering .DSP Devices and Architectures .DSP at EPSON Scotland Design Centre .Summary & Conclusions
What is DSP? Digital Signal Processing – it is a numerical processincal processing of on a digital computer, its images are from images and probes ,voltages generated by the heart and brain,radar and sonar echoes,and countless other application............. ADC Digital Signal Processor Input Signal Output Signal ADC DAC Analogue to Digital Converter Digital to Analogue Converter
What is DSP Used For? …And much more!
Speech Processing 1.Speech coding/compression 2.Speech synthesis 3.Speech recognition
SPEECH CODING 1.Speech code refers to a frame work for communication in a given speech community 2.As an academic discipline , it explores the manner in which groups 3Communicate based on societal ,cultural,gender,occupational and other factors .
Speech Synthesis Applications 1. Speaking clocks 2. Spoken (variable) announcements 3. Talking emails + talking heads for mobile 4. Synthesis of location-based information (e.g. traffic information) 5. Interactive systems (e.g. catalogue orderig ...)
SPEECH RECOGNITION Speech recognition (also known as automatic speech recognition, computer speech recognition, speech to text, or just STT) converts spoken words to text. The term "voice recognition" is sometimes used to refer to recognition systems that must be trained to a particular speaker—as is the case for most desktop recognition software. Recognizing the speaker can simplify the task of translating speech. Speech recognition is a broader solution that refers to technology that can recognize speech without being targeted at single speaker—such as a call system that can recognize arbitrary voices. Speech recognition applications include voice user interfaces such as voice dialing (e.g., "Call home"), call routing (e.g., "I would like to make a collect call"), domotic appliance control, search (e.g., find a podcast where particular words were spoken), simple data entry (e.g., entering a credit card number), preparation of structured documents (e.g., a radiology report), speech-to-text processing (e.g., word processors or emails), and aircraft (usually termed Direct Voice Input)
Audio Coding 1-Key standards: --MPEG: Layers I, II, and III (MP3); AAC. used in DAB, DVD --Dolby AC3, Dolby Digital, Dolby Surround. 2-Typical bit rates for 2-channel stereo: --64kbits/s to 384 kbits/s. 3-Subband- or transform-based, making use of perceptual masking properties.
Image/Video 1-Still Image Coding: --JPEG (Joint Photographic Experts Group): -Discrete Cosine Transform (DCT) based --JPEG2000: Wavelet Transform based 2-Video Coding: --MPEG (Moving Pictures Experts Group): - DCT-based, - Interframe and intraframe prediction, - Motion estimation. --Applications: Digital TV, DVD, etc.
JPEG (100:1) Original JPEG Example JPEG (4:1)
Adaptive Filtering Applications 1-Echo cancellation (telephone lines) --Used in modems (making Internet access possible!!) 2-Acoustic echo cancellation --Hands-free telephony 3-Adaptive equalization 4-Active noise control 5-Medical signal processing --e.g. foetal heart beat monitoring
DSP Devices & Architectures 1-Selecting a DSP – several choices: --Fixed-point; --Floating point; --Application-specific devices(e.g. FFT processors, speech recognizers,etc.). 2-Main DSP Manufacturers: --Texas Instruments --Motorola --Analog Devices
DSP at EPSON Scotland Design “Energy-saving Firmware” Centre EPSON Scotland Design Centre develops a broad range of technologies to minimize power consumption and maximize cost effectiveness in mobile DSP applications.
ADVANTAGES OF DSP 1. Digital signal processing allows sounds to be recorded and transmitted in ways not possible through previously used analog technology. 2.Digital signals are now used in a variety of technologies and disciplines including cell phones, music recording equipment and televisions. 3.The digital signal is also greatly benefited from the Internet, which enables users to send digitally produced audio files from one computer to the other.
Summary & Conclusions • 1-DSP used in a wide range of everyday applications • 2-Looked at: • --Speech coding; Speech synthesis & recognition; • --Image/Video; • --Adaptive filtering. • 3-Other areas include: • -Image analysis (e.g. face recognition, OCR, etc.); • -RADAR/SONAR; • -Data transmission and reception;