An Efficient Adaptive Algorithm for Electron Microscopic Image Enhancement and Feature Extraction

Author(s):  
Vivek Arya ◽  
Vipul Sharma ◽  
Garima Arya

In this article, a block-based adaptive contrast enhancement algorithm has been proposed, which uses a modified sigmoid function for the enhancement and features extraction of electron microscopic images. The algorithm is based on a modified sigmoid function that adapts according to the input microscopic image statistics. For feature extraction, the contrast of the image is very important and authentic property by which this article enhances the visual quality of the image. In this work, for better contrast enhancement of image, a block based on input value, combined with a modified sigmoid function that is used as contrast enhancer provides better EMF values for a smaller block size. It provides localized contrast enhancement effects adaptively which is not possible using other existing techniques. Simulation and experimental results demonstrate that the proposed technique gives better results compared to other existing techniques when applied to electron microscopic images. After the enhancement of microscopic images of actinomycetes, various important features are shown, like coil or spiral, long filament, spore and rod shape structures. The proposed algorithm works efficiently for different dark and bright microscopic images.

Author(s):  
S. K. Paik ◽  
J. R. Allen

Considerable progress in freeze etching technique has been made during the last ten years. The purpose of this technique is the preparation of replicas for electron microscopy. The technique consists of four steps. After (a) freeze-fixation, (b) the specimen surface is fractured with a cooled microtome knife in the vacuum chamber, (c) etched by low temperature sublimation, and (d) a replica of the etched surface is produced by evaporation of platinum and carbon.The electron microscopic image obtained with a freeze-etched replica is highly dependent upon the quality of the replìcas. This quality is very easily affected by the thickness of the evaporated layer and the angle of shadowing.


2019 ◽  
Vol 11 (7) ◽  
pp. 849 ◽  
Author(s):  
Chengwei Liu ◽  
Xiubao Sui ◽  
Xiaodong Kuang ◽  
Yuan Liu ◽  
Guohua Gu ◽  
...  

In this paper, an optimized contrast enhancement method combining global and local enhancement results is proposed to improve the visual quality of infrared images. Global and local contrast enhancement methods have their merits and demerits, respectively. The proposed method utilizes the complementary characteristics of these two methods to achieve noticeable contrast enhancement without artifacts. In our proposed method, the 2D histogram, which contains both global and local gray level distribution characteristics of the original image, is computed first. Then, based on the 2D histogram, the global and local enhanced results are obtained by applying histogram specification globally and locally. Lastly, the enhanced result is computed by solving an optimization equation subjected to global and local constraints. The pixel-wise regularization parameters for the optimization equation are adaptively determined based on the edge information of the original image. Thus, the proposed method is able to enhance the local contrast while preserving the naturalness of the original image. Qualitative and quantitative evaluation results demonstrate that the proposed method outperforms the block-based methods for improving the visual quality of infrared images.


2004 ◽  
Vol 12 (1) ◽  
pp. 3-7
Author(s):  
Stephen W. Carmichael ◽  
Jon Charlesworth

The use of fluorescent probes is becoming more and more common in cell biology. It would be useful if we were able to correlate a fluorescent structure with an electron microscopic image. The ability to definitively identify a fluorescent organelle would be very valuable. Recently, Ying Ren, Michael Kruhlak, and David Bazett-Jones devised a clever technique to correlate a structure visualized in the light microscope, even a fluorescing cell, with transmission electron microscopy (TEM).Two keys to the technique of Ren et al are the use of grids (as used in the TEM) with widely spaced grid bars and the use of Quetol as the embedding resin. The grids allow for cells to be identified between the grid bars, and in turn the bars are used to keep the cell of interest in register throughout the processing for TEM. Quetol resin was used for embedding because of its low auto fluorescence and sectioning properties. The resin also becomes soft and can be cut and easily peeled from glass coverslips when heated to 70°C.


Shinku ◽  
1971 ◽  
Vol 14 (5) ◽  
pp. 178-183
Author(s):  
Hideo TODOKORO ◽  
Tsutomu KONODA ◽  
Mikio ASHIKAWA

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