Survey on different methods in image compression of Brain Images

The survey of brain and medical image compression methods. Reduce the size of image as image compression. Necessity and importance of compression of an image has been discussed. Application of the lossy compression technique is multimedia data. Various compression approaches are discussed for two categories. Also brain image compression techniques are highlighted, in addition with, quantitative comparisons between different compression methods. Also advantages and disadvantages of each method are discussed.


Introduction
This paper describes that for compression of an image lossy compression method is not that much useful. Due to compression method there is possibility of loss in useful information, which has been used for researchers and practitioners. Some operations like enhancement may steer to further deterioration hence there is need of efficient method of image compression. Lossless compression as a better option as a remedy. Many lossless schemes are based on linear prediction and interpolation. There are exploitations of correlation within the image frame, hence context based approach is used popularly. This paper brief about the various coding algorithms & betterment as well as advancement in this field. 1) Lossy compression methods is not that much useful.
2) Due to lossy compression method there is possibility of loss in useful information.
3) Some operations like enhancement may steer to further deterioration hence there is need of efficient method of image compression.
4) Lossless compression used as a remedy.

5)
Various coding algorithms and betterment as well as advancement in this field are discussed.
B) An Overview of Image Compression Approaches by Cebrail Taskin, Serdar Kursat Sarikoz, The Third International Conference on Digital Telecommunications. Findings: 1) The purpose of both compression techniques i.e. lossy and lossless.
2) These techniques are used to reduce the size of the Compressed image size is affected by the ratio of the compression.
3) The ratio of lossless image compression is 2:1 or 3:1. and the ratio varies from 10:1 to 50:1 for the lossy compression. Findings: 1) Brain and medical image compression has discussed.
2) Necessity and importance of compression of an image has been discussed.
Application of the lossy compression technique is multimedia data such as audio, video, and still images.

D) An Overview of Principal Component Analysis by Sasan Karamizadeh, Information Processing
Findings: 1) Importance of PCA in image processing has been discussed.
2) Mainly the basic steps of PCA algorithm are elaborated, which are useful for implementation in the image processing. 1) The quality measurement and assessment i.e. MSE, PSNR Structure-WSNR, NQM, UQI, VSNR, SSIM.
3) Also brief discussion has been carried out on image texture.
4) Image quality assessment based on brightness discrimination, error density and gradient (BDEDG). 2) Importance of quality measurement has been discussed. 1) Simple and efficient algorithm were discussed by using DCT & DWT.
2) DCT gives excellent CR as well as image quality.
3) Wavelet transform is very superior method, for both transform JPEG image is considered. 1) In this work improved quasi-lossless fractal coding scheme is described which preserve the rich features of the medical images.
2) To improve the performance of the fractal coding and to reduce encoding computational complexity machine learning model is used. 1) Study and use of CLAHE is discussed.

3) To evaluate the performance Compression
2) By using "Contrast Limited Adaptive Histogram Equalization (CAHE)" results are improved.
3) CLAHE enhances the visibility of structures that extend across pixel boundaries.
L) A Survey of Medical Image Compression Using Hybrid Techniques by Mr.Amit S.Tajne, International Journal of Computer Science and mobile Computing Findings: 1) Some unique characteristics are used.
2) All compression techniques are useful for real time medical image transmission and storage. Selection of high PSNR value will maintain the quality of the image and achieve successful results of compression process. 2) MBF is introduced to detect micro calcifications.

M) A Hybrid
It describes a new method for the detection of microcalcifications by using morphological bandpass filter. Comparing to DWT method, this method is more accurate in positions and sizes of microcalcifications.

Conclusion
In the entire survey of 15 papers it's found that for betterment and to achieve efficient and accurate coding of the medical images hybrid technique is used. Available compression scheme gives a very high compression rate with some loss of quality which is considerable. For doctors, it is necessary to have high image quality in ROI. This study discusses a hybrid model of lossless compression in ROI & the lossy compression has been used in remaining region. Computers are preferably used for keeping images. To store amount of data, space is issue. Sufficient space is required to send the data or data should be compressed. To dominate these disadvantages image compression techniques are used.