Computed Tomography or CAT Scans/FBP


how image is reconstructed using filtered back projection?? i need to know a little bit about how to implement it(i mean pseudo code or something like that)??

And what are it's advantages over other image reconstruction techniques??

waiting for your kind reply??

thank u..

In filtered back projection method the projections are first convoluted to a suitable high pass filter and then the back projection is carried out to get the reconstructed image. In back projection the projections in the acquisition stage are just reversed with the same affected gray levels those are obtained after normalization.

The pseudo code can be generated by downloading one of my papers those are carrying the flow charts related to this well known commercial technique.

This technique is quick, easy to implement in programming and accompanying lesser computational load.


Dr. Shahzad.

Computed Tomography or CAT Scans

All Answers

Answers by Expert:

Ask Experts


Dr. Shahzad Ahmad Qureshi


I can answer questions about transmission computed tomography, simulated annealing-based tomography and binary & continuous genetic algorithms-based tomography. I shall not be able to answer as an expert about MRI, fMRI...


I have an eight year experience as a researcher.

National Institute of Lasers and Optronics, Islamabad, Pakistan.


1. S. A. Qureshi, S. M. Mirza, Nasir M. Rajpoot, Member IEEE, and M. Arif A Novel GA Approach to Tomographic Image Reconstruction, IEEE Trans. Image Processing, Vol. 20, Issue 7, pp. 1977-1990, 2011 (Online ISSN: 1057-7149, DOI: 10.1109/TIP.2011.2107328) ISI index: 4.205, 2011

2. S. A. Qureshi, S. M. Mirza, and M. Arif Hybrid Simulated Annealing Image Reconstruction for Parallel-Ray Transmission Tomography, Inverse Problems in Science and Engineering, Taylor & Francis, Vol. 17, Issue 5, pp. 647-664, 2009 (Online ISSN: 1741–5985, Print ISSN: 1741–5977, DOI: 10.1080/17415970802390085) ISI index: 0.416, 2008

3. S. A. Qureshi, S. M. Mirza, and M. Arif Determination of Optimal Number of Projections and Parametric Sensitivity Analysis of Operators for Parallel-Ray Transmission Tomography using Hybrid Continuous Genetic Algorithm, International Journal of Imaging Systems and Technology, Vol. 17, Issue 1, pp. 10-21, 2007 (Online ISSN: 1098-1098, Print ISSN: 0899-9457, DOI: 10.1002/ima.20093), ISI index: 0.983, 2006

4. S. A. Qureshi, S. M. Mirza, and M. Arif Optimization of Projections for Parallel-Ray Transmission Tomography using Genetic Algorithm, in Wireless Networks, Information Processing and Systems, Vol. 20, Issue 3, pp. 20-39, 2006, Springer Berlin Heidelberg, 2008 (Online ISSN: 1865-0929, Print ISSN: 1865-0937, Online ISBN: 978-3-540-89852-8, Print ISBN: 978-3-540-89853-5, DOI: 10.1007/978-3-540-89853-5_6)


PhD (Computer Science), MS (Nuclear Engg.), MSc (Computer Science), BE (Metallurgical Engg. and Materials Science)

Awards and Honors

• Fellowship for Ph.D. in Computer Science by Higher Education Commission, Islamabad (2004).

• Fellowship for Research Work at the University of Warwick, the United Kingdom during PhD in the Image Processing Group at the Department of Computer Science (2008)

• Fellowship for M.Sc. Nuclear Engineering from Quaid-i-Azam University, Islamabad for the session 1994-96

• University Merit Scholarship by UET, Lahore awarded every year for being declared as the Top Student during BE

• Gold Medalist of BE with HONOURS by UET, Lahore for the session 1988-92

• Secured Bull’s Eye (100% score) in TCP/IP 4.0 and 90% in Networking Essentials and Microsoft Windows NT 4.0 Workstation (MCSE)

©2017 All rights reserved.