We have developed a method for the linear reconstruction of an image from undersampled, dithered data. The algorithm, known as Variable-Pixel Linear Reconstruction, or informally as ``Drizzle,'' preserves photometry and resolution, can weight input images according to the statistical significance of each pixel, and removes the effects of geometric distortion on both image shape and photometry. This paper presents the method and its implementation. The photometric and astrometric accuracy and image fidelity of the algorithm as well as the noise characteristics of output images are discussed. In addition, we describe the use of drizzling to combine dithered images in the presence of cosmic rays.
Publications of the Astronomical Society of the Pacific
- Pub Date:
- February 2002
- Methods: Data Analysis;
- Techniques: Photometric;
- 19 pages, 5 figures, accepted for publication in February 2002 PASP. Major changes and much additional material since original submission in 1998