Journal ArticleDOI
Halftone screen techniques for photographic film response shaping with application to optical processing of medical x-ray images.
I. Glaser,H. H. Barrett +1 more
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TLDR
This work presents several methods, all using halftone screens, to obtain proper response from the input photographic film, and demonstrates one particular method, both theoretically and experimentally, as applied to x-ray recording of coded images that are to be used as input for an optical transaxial tomography processor.Abstract:
Optical image processing is notoriously sensitive to nonlinearities in the input medium; many otherwise successful optical processors fail to perform adequately outside the laboratory environment because of this problem. The usual solutions to the problem-use of special photographic emulsions, developers, and even preexposure (bias)-severely limit the applicability of many optical processing schemes and may also degrade the SNR of the input image. We present several methods, all using halftone screens, to obtain proper response from the input photographic film. We then demonstrate one particular method, both theoretically and experimentally, as applied to x-ray recording of coded images that are to be used as input for an optical transaxial tomography processor.read more
Citations
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Journal ArticleDOI
Incoherent optical processor for x-ray transaxial tomography
TL;DR: A single-channel incoherent optical processor that reconstructs an object from its 1-D x-ray projections has been developed and should offer equivalent performance at a reduced cost.
Journal ArticleDOI
Grazing incidence tomography
G Thuesen,A Lindegaard-Andersen +1 more
TL;DR: It is shown that unfiltered, transaxial tomographic summation images can yield high-quality tomograms of high-contrast objects and an improvement of the method seems possible.
Journal ArticleDOI
Phase information in binary image encoding
Dieter Just,Olof Bryngdahl +1 more
TL;DR: The explicit introduction of phase information in implicit passive binarization procedures is demonstrated and a doubling of the number of quantization levels without changing other parameters is demonstrated.
Book ChapterDOI
I Optical and Electronic Processing of Medical Images
TL;DR: Some of the most important applications of the processing of images to medical problems are described in this chapter, with special emphasis on the optical methods, although digital and electronic procedures are also mentioned.
Journal ArticleDOI
Adaptive optical nonlinear image processing
TL;DR: This work proposes a method of implementing input-dependent nonlinear image processing optically, which simplifies and automates some image processing operations that require response curves that depend on some input image characteristics.
References
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Journal ArticleDOI
Analog reconstruction methods for transaxial tomography
TL;DR: Transaxial tomography is a radiographic technique that provides an image of an isolated two-dimensional section of a three-dimensional object as mentioned in this paper, and the equivalence of various mathematical formulations is shown The properties of the resulting image for various filter functions are described and limitations imposed by the quantum statistics of the radiation source are briefly discussed.
Journal ArticleDOI
Operations achievable with coherent optical information processing systems
TL;DR: This paper reviews the operations commonly achieved in the past, and discusses newer techniques which are capable of significantly extending the class of achievable operations.
Journal ArticleDOI
Linear Multiple Image Storage
TL;DR: This work presents a novel optical multiplex scheme that combines four continuous tone image exposures multiplied by a unique spatial carrier, and the resulting exposure products are added sequentially on a single emulsion.
Journal ArticleDOI
Nonlinear transformations and logarithmic filtering in coherent optical systems
Hisatoyo Kato,Joseph W. Goodman +1 more
TL;DR: A contact screen which performs a logarithmic transformation has been studied both theoretically and experimentally and its possible applications include removal of speckle, extraction of images from multiplicative noise, and biomedical image processing.
Journal ArticleDOI
Equidensitometry by coherent optical filtering
TL;DR: A new and simple method has been developed for fabrication of multilevel halftone screens that have proved useful for generation of equidensity contours by means of coherent optical filtering and the possible application of this method to optical analog-to-digital conversion using a single Halftone photograph is discussed.