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Digital Image Processing. 7 Wavelets and Multiresolution Processing. Preview. 7.1 Background. Multiresolution Objects, which are of small size or of low contrast, require high resolution; Objects, which are of large size or of high contrast, often only require low resolution.
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Digital Image Processing 7 Wavelets and Multiresolution Processing
7.1 Background • Multiresolution • Objects, which are of small size or of low contrast, require high resolution; • Objects, which are of large size or of high contrast, often only require low resolution. • Statistics features
7.1.3 The Haar transform • Principle • Basis functions of the Haar transform are the oldest and simplest known orthonormal wavelets. • Expression of the Haar transform T = HFH where F is an image, H is the Haar transform. • An instance of the Haar transform
7.2 Multiresolution expansion • Series expansion • Scaling functions • Integer translation • Binary scaling
7.2 Multiresolution expansion • Wavelet functions • Definition • An example: the Haar wavelet function
7.3 Wavelet transform in one dimension • The wavelet series expansions • Expression • Approximation coefficients • Wavelet coeffients
7.3 Wavelet transform in one dimension • An example of the Haar wavelet series expansion
7.3 Wavelet transform in one dimension • The discrete wavelet transform • Definition
7.3 Wavelet transform in one dimension • The continuous wavelet transform • Definition • The inverse continuous wavelet transform
7.5 Wavelet transform in two dimension • Two dimensional scaling function (x, y) = (x) (y) • Two dimensional wavelet functions H(x, y) = (x) (y) V(x, y) = (x) (y) D(x, y) = (x) (y) • The scaled and translated basis functions
7.5 Wavelet transform in two dimension • Definition • The inverse discrete wavelet transform