This paper presents the nine wavelet techniques used for compression and uncompression of gray scale and true
color images. The valid compression methods are divided in three categories. 1) Progressive coefficients significancemethods (PCSM) which contains EZW (Embedded Zero Tree Wavelet), SPIHT (Set Partitioning in Hierarchical Trees), STW (Spatial Orientation Tree Wavelet), WDR(Wavelet Difference Reduction), ASWDR (Adaptively Scanned Wavelet Difference Reduction), SPIHT 3D(Set Partitioning In Hierarchical Trees 3D for true color image) methods. 2) Coefficient
Thresholding Methods (CTM-1) which contains Sub band thresholding of coefficient and Huffman encoding. 3) Coefficient thresholding methods (CTM-2) which contain Global thresholding of coefficients and fixed encoding, Global Thresholding of coefficients & Huffman encoding. In this paper Comparison of different quality assessment metrics for the enhancement and compression techniques are carried out. This comparison is done .