Showing papers on "Histogram equalization published in 1981"
TL;DR: Two contrast-modification techniques for the display of scintigraphic images are developed that improve the readability of data, but are often far from usual images and necessitate an apprenticeship for the physician.
Abstract: this article develops two contrast-modification techniques for the display of scintigraphic images. Based on histogram-modification techniques, histogram equalization, where each level of gray is used to the same extent, gives maximum entropy. The first technique uses the application of histogram equalization in the whole image. To eliminate contrast attenuation in image areas that represent a statistically small but important portion of the gray scale histogram, local area histogram equalization has been applied to images with differences in intensity. Both techniques were tested using a phantom with known characteristics. The global equalization technique is more suitable to bone scintigraphies, and some well-chosen boundaries improved the differnce between two comparable areas. For liver scintigraphies, where intensity is quite equal in every pixel, a local area equalization was chosen that allowed detection of heterogeneous structures. The images resulting from histogram-equalization techniques improve the readability of data, but are often far from usual images and necessitate an apprenticeship for the physician.
14 citations
TL;DR: Limited experience to date indicates that false color conversion is probably more useful than histogram equalization in black and white and that this system is particularly valuable for rotational averaging and selected area Fourier transforms.
14 citations
28 Jul 1981
TL;DR: This paper reviews briefly some of the previous work done with the EIKONIX Diffusion Model Transformation (DMT) as an image enhancement algorithm for electro-optical imagery and compares the technique to some other common forms of image enhancement, such as linear high pass filtering - homomorphic highPass filtering - histogram remapping.
Abstract: This paper reviews briefly some of the previous work done with the EIKONIX Diffusion Model Transformation (DMT) as an image enhancement algorithm for electro-optical imagery. It also compares the technique to some other common forms of image enhancement, such as: - linear high pass filtering - homomorphic high pass filtering - histogram remapping The DMT produced results superior to the other enhancement methods. A combination of the DMT and histogram equalization proved still better.© (1981) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
1 citations