ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

Table 1: quantitative criteria used for phantom image.
criteria Noisyimage
WST Contrast
MSE 53 24 38
SNR (dB) 8.3 15.8 11.3
The methods described in the methods section were applied on some ultrasound images
with some selected areas of interest. First, a WST filtering was applied on six
ultrasound images, an example of real ultrasound image is shown in figure 3 a. Wavelet
decomposition of level two with biorthogonal 3.5 basis was used during enhancement
process.
a b c
Figure 3 ( a) original image, (b) result of multiresolution contrast enhancement method, and (c) result of
the wavelet soft thresolding method, (d) segmentation of (b); (e) segmentation of (c) using snack
algorithm.
A soft-thresholding of two standard deviations as in(3) was applied on the first level
of detail components and one SD on the second level of components details, the
resulting image is shown in figure 3.
Figure 3.a shows an original image, 2b shows filtered image using a contrast method. A
two level contrast pyramid was used. A median filter of size 5x5 was applied on the
first level of contrast and a median filter of size 3x3 at the second level. Then,
subsequently, a reconstruction was used in order to obtain the enhanced image. It is
difficult for non-expert in the diagnoses of ultrasound images to notice the difference
between the two enhanced images. Fig 3.c shows the result of the wavelet soft
thresholding method. Figure 3d shows the segmented region using snack algorithm
after despeckling using contrast enhanced method. Figure 3e shows the segmented
region using the same segmentation algorithm after despeckling using WST method.
4. CONCLUSIONS
d e
5