We are working with speckle noise reduction in ultrasound images by using various despeckling filtering techniques. We compare the performance of each filtering technique by using Quality metrics such as mean square error,signal to noise ratio,peak signal to noise ratio,Edge preservation index,Speckle index.
We know that mean square error metric indicates how different the images being compared are. Therefore the lower its value is,the closer the estimated image is to the original image. The peak signal to noise ratio must be high which indicates an improvement in speckle reduction.But when we calculate these metrics, mean square error is high and Peak signal to noise ratio is small. any one please say me why this happens so.
The original image that we have used is shown below
Then we corrupted the original image with 3% noise
The formula that we used to calculate these metrics is given below
The result which we obtain while using median filter is given below