Improved Feature Localization Through Broadband Image Processing
Van Keuren, Edward
Traditional photographic digital images are acquired from an array of photodetector elements whose physical size and location define the image pixels. Each element measures the amount of light incident upon it. The images used in our research are produced from a raster scan of focused broadband terahertz (THz) pulses. Each resulting pixel contains the THz waveform (temporal and spectral) measured at its scan location. However, the quality of such images is non-optimal because of the broadband nature of the measurement pulses. Since the focal spot diameter of a focused beam is proportional to the wavelength, a broadband pulse contains a plurality of focal spot sizes. This focal spot size range results in pixel ambiguity. A spot of diameter less than the pixel size yields unmeasured space within a given pixel. A spot of diameter greater than the pixel size yields information outside a given pixel being attributed to that pixel. This research focuses on developing an image processing algorithm to improve feature localization and edge definition by correcting this ambiguity. The algorithm achieves this goal by using the measured waveform for each pixel to determine the signal from each component spot contained within a pulse. We used the signal from these component spots within a pixel in combination with its neighboring pixels to more precisely localize feature edges. The algorithm has the potential to enhance images from a variety of applications, including the initial intended use in THz imaging for nondestructive test and evaluation.
MetadataShow full item record
Showing items related by title, author, creator and subject.
Generalizing on Best Practices in Image Processing: A Model for Promoting Research Integrity: Commentary On: Avoiding Twisted Pixels: Ethical Guidelines for the Appropriate Use and Manipulation of Scientific Digital Images Benos, Dale J; Vollmer, Sara H (2010-12)Modifying images for scientific publication is now quick and easy due to changes in technology. This has created a need for new image processing guidelines and attitudes, such as those offered to the research community by ...