  In remote sensing, image fusion technique is a useful tool used to fuse high
spatial resolution panchromatic images (PAN) with lower spatial resolution
multispectral images (MS) to create a high spatial resolution multispectral of
image fusion (F) while preserving the spectral information in the multispectral
image (MS).There are many PAN sharpening techniques or Pixel-Based image fusion
techniques that have been developed to try to enhance the spatial resolution
and the spectral property preservation of the MS. This paper attempts to
undertake the study of image fusion, by using two types of pixel-based image
fusion techniques i.e. Arithmetic Combination and Frequency Filtering Methods
of Pixel-Based Image Fusion Techniques. The first type includes Brovey
Transform (BT), Color Normalized Transformation (CN) and Multiplicative Method
(MLT). The second type include High-Pass Filter Additive Method (HPFA),
High-Frequency-Addition Method (HFA) High Frequency Modulation Method (HFM) and
The Wavelet transform-based fusion method (WT). This paper also devotes to
concentrate on the analytical techniques for evaluating the quality of image
fusion (F) by using various methods including Standard Deviation (SD),
Entropy(En), Correlation Coefficient (CC), Signal-to Noise Ratio (SNR),
Normalization Root Mean Square Error (NRMSE) and Deviation Index (DI) to
estimate the quality and degree of information improvement of a fused image
quantitatively.
