Nonseparable 2D FIR filter design using nonuniform frequency sampling

Sonali Bagchi; Sanjit K. Mitra

doi:10.1117/12.205470

23 March 1995 Nonseparable 2D FIR filter design using nonuniform frequency sampling

Sonali Bagchi, Sanjit K. Mitra

Proceedings Volume 2421, Image and Video Processing III; (1995) https://doi.org/10.1117/12.205470
Event: IS&T/SPIE's Symposium on Electronic Imaging: Science and Technology, 1995, San Jose, CA, United States

Abstract

We propose a nonuniform frequency sampling method for 2D FIR filter design based on the concept of the nonuniform discrete Fourier transform (NDFT). The NDFT of a 2D sequence is defined as a sequence of samples of its z-transform taken at distinct points located arbitrarily in the (z₁, z₂) space. In our design method, we determine the independent filter coefficients by taking samples of the desired frequency response at points located nonuniformly on the unit bi-disc, and then solving the linear equations given by the NDFT formulation. The choice of sample values and locations depends on the shape of the 2D filter. Best results are obtained when samples ar placed on contour lines that match the desired passband shape. The proposed method produces nonseparable filters with good passband shapes and low peak ripples. In this paper, we consider the design of square- and diamond-shaped filters. Extensive comparisons with filters designed by other methods demonstrate the effectiveness of the proposed method. We also investigate the performances of the filters designed by applying them as prefilters and postfilters to schemes for rectangular and quincunx downsampling of images. Examples show that the filters designed by our method produce output images which are sharper and have a higher PSNR, as compared with other filters.

Citation Download Citation

Sonali Bagchi and Sanjit K. Mitra "Nonseparable 2D FIR filter design using nonuniform frequency sampling", Proc. SPIE 2421, Image and Video Processing III, (23 March 1995); https://doi.org/10.1117/12.205470

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available