Image processing technique is a method of improving the quality of an image. Many image processing operations can be grouped into some method. These are image representation, image preprocessing, image enhancement, image restoration, image analysis, image reconstruction and image data compression. Many images contain a lot of irrelevant and unwanted parts. The process of enhancing pixel intensity and image quality are also carried out after preprocessing. Image preprocessing is enhancement the quality of the image because it is eliminating noise and reducing the distortions of the input images. Thus, preprocessing techniques require for images because it is contained annoying parts in an image. Image filtering is a standard process used in almost every image processing system. In this paper, we describe the various images filtering techniques and filtering algorithms used for image filtering or smoothing. Image smoothing is one of the most important in image processing and it is widely used in image application and which algorithm is the best for smoothing and filtering the images. Image smoothing is to reduce noise and improve the visual quality of the image. The proposed system describes the median filtering, Gaussian high filtering and Gaussian low filtering in preprocessing techniques. The median filter used to remove noise and it is a nonlinear digital filtering technique. Gaussian High pass filters are usually used for sharpening. The filtering techniques have been simulated using Matlab 2018a. In performance of this filtering technique, low pass filtering technique is better and its takes less processing time than other filtering methods. After the preprocessing, the image quality is increase.