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This chapter presents two important DSP techniques, the overlap-add method, and FFT convolution. The overlap-add method is used to break long signals into smaller segments for easier processing. FFT convolution uses the overlap-add method together with the Fast Fourier Transform, allowing signals to be convolved by multiplying their frequency spect...

8 trang | Chia sẻ: tlsuongmuoi | Ngày: 22/02/2013 | Lượt xem: 2113 | Lượt tải: 0

Program PTB2; Var a,b,c:Integer; delta,x1,x2:Real; Begin Writeln('GIAI PHUONG TRINH BAC HAI'); Writeln(' --------------'); Repeat Write('-Nhap he so a= '); Readln(a); Until a <>0; Write('-Nhap he so b= '); Readln(b); Write('-Nhap he so c= '); Readln(c); delta:=b*b-4*a*c; If delta < 0 Then Writeln('*Phuong trinh vo nghiem') ...

4 trang | Chia sẻ: tlsuongmuoi | Ngày: 22/02/2013 | Lượt xem: 1932 | Lượt tải: 2

Recursive filters are an efficient way of achieving a long impulse response, without having to perform a long convolution. They execute very rapidly, but have less performance and flexibility than other digital filters. Recursive filters are also called Infinite Impulse Response (IIR) filters, since their impulse responses are composed of decaying ...

14 trang | Chia sẻ: tlsuongmuoi | Ngày: 22/02/2013 | Lượt xem: 1970 | Lượt tải: 0

Chebyshev filters are used to separate one band of frequencies from another. Although they cannot match the performance of the windowed-sinc filter, they are more than adequate for many applications. The primary attribute of Chebyshev filters is their speed, typically more than an order of magnitude faster than the windowed-sinc. This is because th...

10 trang | Chia sẻ: tlsuongmuoi | Ngày: 22/02/2013 | Lượt xem: 2064 | Lượt tải: 0

Decisions, decisions, decisions! With all these filters to choose from, how do you know which to use? This chapter is a head-to-head competition between filters; we'll select champions from each side and let them fight it out. In the first match, digital filters are pitted against analog filters to see which technology is best. In the second round,...

8 trang | Chia sẻ: tlsuongmuoi | Ngày: 22/02/2013 | Lượt xem: 2107 | Lượt tải: 0

Audio processing covers many diverse fields, all involved in presenting sound to human listeners. Three areas are prominent: (1) high fidelity music reproduction, such as in audio compact discs, (2) voice telecommunications, another name for telephone networks, and (3) synthetic speech, where computers generate and recognize human voice patterns. W...

22 trang | Chia sẻ: tlsuongmuoi | Ngày: 22/02/2013 | Lượt xem: 2117 | Lượt tải: 0

For every time domain waveform there is a corresponding frequency domain waveform, and vice versa. For example, a rectangular pulse in the time domain coincides with a sinc function [i.e., sin(x)/x] in the frequency domain. Duality provides that the reverse is also true; a rectangular pulse in the frequency domain matches a sinc function in the tim...

16 trang | Chia sẻ: tlsuongmuoi | Ngày: 22/02/2013 | Lượt xem: 2032 | Lượt tải: 0

Images are a description of how a parameter varies over a surface. For example, standard visual images result from light intensity variations across a two-dimensional plane. However, light is not the only parameter used in scientific imaging. For example, an image can be formed of the temperature of an integrated circuit, blood velocity in a patien...

24 trang | Chia sẻ: tlsuongmuoi | Ngày: 22/02/2013 | Lượt xem: 5555 | Lượt tải: 0

Linear image processing is based on the same two techniques as conventional DSP: convolution and Fourier analysis. Convolution is the more important of these two, since images have their information encoded in the spatial domain rather than the frequency domain. Linear filtering can improve images in many ways: sharpening the edges of objects, redu...

26 trang | Chia sẻ: tlsuongmuoi | Ngày: 22/02/2013 | Lượt xem: 2028 | Lượt tải: 0

This chapter presents four specific aspects of image processing. First, ways to characterize the spatial resolution are discussed. This describes the minimum size an object must be to be seen in an image. Second, the signal-to-noise ratio is examined, explaining how faint an object can be and still be detected. Third, morphological techniques are i...

28 trang | Chia sẻ: tlsuongmuoi | Ngày: 22/02/2013 | Lượt xem: 1978 | Lượt tải: 0