backprojection

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back·pro·jec·tion

(bak'prō-jek'shŭn),
In computed tomography or other imaging techniques requiring reconstruction from multiple projections, an algorithm for calculating the contribution of each voxel of the structure to the measured ray data, to generate an image; the oldest and simplest method of image reconstruction. Compare: Fourier analysis.
Farlex Partner Medical Dictionary © Farlex 2012

back·pro·jec·tion

(bak'prŏ-jek'shŭn)
In computed tomography or other imaging techniques requiring reconstruction from multiple projections, an algorithm for calculating the contribution of each voxel of the structure to the measured ray data, to generate an image; the oldest and simplest method of image reconstruction.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
However, Wu's scheme is vulnerable to geometric attacks such as cropping, scaling, rotation, and histogram equalization, whereas our scheme is able to withstand such attacks.
Results of histogram equalization and FFT presented in (Fig-2) and (Fig-3) respectively.
This paper presents an algorithm that preprocess the image and then extract the features after applying the histogram equalization. Good results are obtained from the implemented of this algorithm.
The robustness is expressed in terms of BER (%) after mean filter (Figure 8), JPEG compression (Figure 9), median filter (Figure 10) and gamma correction, Poisson noise, histogram equalization, and image unsharpening (Figure 11).
Karthikeyan and Poornima [14] used histogram equalization and median filtering for preprocessing of ALL images and then fuzzy C-means was used to segment out the white blood cells and after extracting features using Gabor texture extraction method support vector machine was used for classification of blasted cells.
(a) Gaussian filter 39.482 Laplacian filter 2.838 Wiener filter 50.687 Mean filter 33.194 Median filter 45.836 (b) Intenstiy adjustment 1.299 Histogram equalization 1.276 CLAHE 1.328 Note: Table made from bar graph.
Figure 2(b) shows the result of histogram equalization. After histogram equalization, the contrast of the piglets is enhanced, but the image is susceptible to noise, shadow, and light changes.
Consequently, the histogram equalization is presented to stretch the image histogram to extract more details from the image.
Caption: FIGURE 6: CT image modification detection rates for different centered block sizes and various modification types: (a) JPEG2000, (b) Gaussian filtering, (c) Laplacian filtering, (d) brightening, (e) scaling, (f) histogram equalization, (g) JPEG compression.
Histogram equalization (HE) [7] is most extensively utilized for contrast enhancement.
[3] Another method is the improved image contrast enhancement using histogram equalization which goes well with multiple-peak images.