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FIGURE 13. How ART algorithm works. (A) Problem is to find values of 4 pixels given values in 6 bins. (B) ART algorithm: Difference between estimated and measured projections is computed and divided by number of pixels in given direction. Result is added to current estimate. (C) First step: Project initial estimate (zeros) in vertical direction, apply ART algorithm, and update pixel values. Repeat this process for oblique (D) and horizontal (E) rays. (F) Solution is obtained after 1 full iteration. However, with larger images, more iterations are typically required.
