| Image: low frequency events are spread out in time and high frequency events are localized in time |
| Further structure of Image is not uniform over x or y direction of image but rather in blocks where say head or a particular detail is. This is why JPEG uses FFT's in blocks. Wavelets automatically build in block structure adaptively so get more detail where you need it. |
| sines or cosines (FFT) - cannot provide information about the time behavior of signal because they have infinite support |
| impulse function - frequency behavior is not described because of its infinitesimally small support |
| wavelets - set of basis functions, each with finite support of a different width |
| wide variety of wavelet-based image compression schemes reported in the literature |