Visual data transmitted in the form of digital images is becoming a main method of digital communication but the received image is to be processed before it can be used in applications. Image denoising involves administration, control, handing of the image data to produce a visually high quality image. So that Denoising is the first and last step to be taken before the images is used for any application. Noise is added due to data transmission reception, necessary to apply a suitable denoising method. This paper presents a brief introduction of some image denoising methods. Potential future trends in the area of denoising are also mentioned.