International Journal of Engineering Trends and Technology (IJETT) – Volume 18 Number1- Dec 2014 Statistical analysis of Image restoration using GeometricTransform approach Ankita Sharma #1, Uday Bhan Singh#2, Ankur Chourasia#3 #1 #2,3 M.Tech Scholor IASSCOM Fortune Institute of Technology, Bhopal, India Assistant Professor IASSCOM Fortune Institute of Technology, Bhopal, India Abstract— While digital imaging systems have been widely used for many applications including consumer photography, microscopy, aerial photography, astronomical imaging, etc., their output images/videos often suffer from spatially varying blur caused by lens, transmission medium, post processing algorithms, and camera/object motion. Measuring the amount of blur globally and locally is an important issue. It can help us in removing the spatially varying blur, and enhancing the visual quality of the imaging system outputs. In this paper, we study the blur measurement problem for different scenarios. We have applied the Geometric Transformation algorithm for restoration of the blurred image. First we apply it for that image where there is only spatial variation in terms of coordinate geometry by keeping the neighborhood pixels orientation constant. Then we apply the algorithm for the case where there is geometric variation spatial as well as local. In both cases we estimated the PSNR & MSE value. Geometric Transformation methods provide us an easiest way to restore the match because here only matched features points are involved in the process, Whereas in local probability estimation we have to concentrate over all pixels and then cause so the computation become complex and hence it enhances the cost of the system. the terms and the expression of the contents, thus we may lose the part of the contents as a result. Using telephone and video chat such as Skype indirect communication can be achieved across space but not time. For communication across time, the better way is written communication. Ancient people used pictograph, resemblance of objects for the purpose. They painted images onto walls or incised into stones using mineral pigments. Figure 1 shows a cave painting of a horse drawn by CroMagnon peoples. Even though we have no idea what they wanted to tell by such pictograph, the graph can tell the information of the era. Printing technology further encouraged this type of communications, especially for text. Keywords— Geometric transformation, Image, Noise. PSNR, MSE, Restoration I. INTRODUCTION When we convey a thing to others, how do we do? In face to face communication, we rely on both oral and non-verbal communication. Oral communication, spoken verbal communication in other words, typically relies on words. In contrast, non-verbal communication meaning wordless communication relies on gesture and facial expression and etc. When we want to do it across time and space, what should we do? The oldfashioned way follows the above type of communications. For example, folk stories and songs passed by word of mouth are categorized into this type. However, the reprise of such style varies ISSN: 2231-5381 Figure 1: Written communication at ancient time: Cave painting of a horse at Lascaux drawn by CroMagnon peoples. A big leap in the technology occurred by printing press technology intended in the 15th century. The printing-press devices enabled rapid and precise copy of text document. This is the reason why the invention and spread of the technology are regarded as the revolutionizing events in the second millennium. With the printing technology, the contents can be preserved semi-permanently an idiom seeing is believing means that physical or concrete evidence is convincing. This http://www.ijettjournal.org Page 1 International Journal of Engineering Trends and Technology (IJETT) – Volume 18 Number1- Dec 2014 indicates that conveying a thing prefers showing the thing rather than telling the thing. Thus, it is natural that we have developed devices taking a photograph, an image of projecting lights of a scene. Before the first photographs, the principal of pinhole camera was mentioned by Mo Di, Chinese philosopher, and Aristotle, Greek mathematician, in the fifth and fourth centuries BC. Camera obscura consisting of a box or a room with a hole in one side is the concrete device of pinhole camera. Light from an external scene of the camera passes through the hole and then reaches a surface inside. The image of the scene can be projected onto the surface, and can then be manually traced to produce a photograph of the scene. Joseph Nic´ephore Ni´epce, a French inventor, invented revolutionizing camera like printing-press technology for text [2]. His key idea is to omit manual drawing from imaging process by relying on photochemical action so that we can automatically obtain a photograph. Before Ni´epce, photographs were not permanent, unable to permanently secure the images from fading. Gorman mentioned that his camera was designed based on heliograph [3]. camera takes two steps to provide the observation of the photograph as shown in Fig. 1.3, while Ni´epce’s camera directly generated a photo of the scene via one process. First process is image acquisition process. The process receives lights from the scene and then converts the received light as the latent image. For this process, film camera uses photographic film or plate while digital camera uses imaging sensor, e.g., a Charge Coupled Device (CCD) image sensor or Complementary Metal-Oxide-Semiconductor (CMOS) sensor. Figure 3: Imaging processes of digital camera: Image acquisition process converts the energy of lights coming from the target scene to measurable value. Image display process shows the digital image using a display device. Next is image display process. This step transforms the latent image into a visible image. For images saved on the film, we follow photographic processing, which is the chemical ways to produce a negative or positive image. On the other hand, digital image has various ways of displaying the photo. One may use printers to make the photo permanent while another may use display devices to see the photo temporarily. Figure 2: The earliest surviving photograph of a scene from nature taken with a camera obscura: View from the Window at Le Gras Figure 2 shows the earliest surviving photograph taken by Ni´epce. The big limitation of Ni´epce’s camera is its exposure time. It takes about eight hours for the camera to yield the photochemical action. Thus, his follower focused on achieving shorter exposure time. Through the 19th century, many advances in photographic glass plates and printing were made in. George Eastman replaced photographic plates to photographic film. This replacement was distributed through the late 19 century and results the technology of today’s film camera. Nowadays, digital cam- era is one of the most popular devices for photo shooting. The difference between digital camera and film camera is their memory media. As memory medium, film camera uses photographic film while digital camera does memory devices such as memory card by converting the received light to digital data format via an electronic image sensor. Digital ISSN: 2231-5381 Typical display device is computer monitors including Cathode Ray Tubes (CRT) display and Liquid Crystal Display (LCD). Thanks to the recent development of display technologies, bigger and brighter display is available with cheaper cost. In contrast to such monitors, projectors only have light emitting devices. To form an image, projectors require display surface, onto which they emit the light. I.I Problem definition: What is image denoising? Image denoising is the problem of finding a clean image, given a noisy one. In most cases, it is assumed that the noisy image is the sum of an underlying clean image and a noise component. Figure:3 A noisy images are assumed to be the sum of an underlying clean image and noise. http://www.ijettjournal.org Page 2 International Journal of Engineering Trends and Technology (IJETT) – Volume 18 Number1- Dec 2014 In case of image denoising methods, the characteristics of the degrading system and the noises are assumed to be known beforehand. The image s(x,y) is blurred by a linear operation and noise n(x,y) is added to form the degraded image w(x,y). This is convolved with the restoration procedure g(x,y) to produce the restored image z(x,y). The “Linear operation” shown in Figure 3 is the addition or multiplication of the noise n(x,y) to the signal s(x,y) [4]. Figure 4: Degradation model Literature survey on the Image Restoration technique explores the various ways to restore the image. There are lots of algorithms suggested and implemented for denoising and defocusing the image. The prime objective of the thesis is to restore the image based on Geometric transform estimation algorithm. The objective can be characterized as: Image restoration using Geometric Transform Estimation technique (Feature matching) & performance analysis based on PSNR & MSE evaluation. II DESIGN METHODOLOGY The algorithm finds the featured values like edges, corner, inliers and outliers points from the original and transformed image and based on these information it restore the image. MATLAB software will be used to implement this research work. Proposed algorithm for the research methodology can be illustrated as follows: As discussed the methodology adopted for the implementation of Geometrical Estimation algorithm to find out the deblur image when there is uniform variation of pixel throughout the image at particular angle it is important to consider the image size. Several techniques have been proposed for the denoising of an image when the user has the apriori knowledge of the feature of image in terms of PSF. But when it is unknown the retrieval of the image becomes complex. The first step is image acquisition that include image capturing, resizing and refining the image data that has to be processed. III.I Steps for Deblurring using Geometrical Transform Estimation Algorithm: Figure 5: Original Image gathered from Image acquisition Original image is treated with transformation and each pixel of the image is rotated with 31 degree. This is called uniform ISSN: 2231-5381 http://www.ijettjournal.org Page 3 International Journal of Engineering Trends and Technology (IJETT) – Volume 18 Number1- Dec 2014 geometrical displacement when the relative distance between the pixels is unchanged but the geometrical position has been changed. To get this type of image we use simple rotation technique of the image because in rotation the distance between the pixels remains constant but the geometrical location changed. Table No. 1: SURFPoints (Properties): SURFPoints Object for storing SURF interest points: The main purpose of this class is to pass the data between detect SURFF features and extract Features functions. It can also be used to manipulate and plot the data returned by these functions. Using the class to fill the points interactively is considered an advanced maneuver. It is useful in situations where you might want to mix a non-SURF interest point detector with a SURF descriptor. 'Orientation' is specified as an angle, in radians, as measured Count Location Scale Metric: Sign Of Laplacian Orientation 428 428x2 single 428x1 single 428x1 single 428x1 int8 428x1 single from the X-axis with the origin at 'Location'. 'Orientation' should not be set manually. You should rely on the call to extract Features for filling this value. 'Orientation' is mainly useful for visualization purposes. Figure 6: Transformed Image After transformation our task is to detect and extract the features of original Image and Transformed image. To detect the robust feature of the gray scale image from which we can inculcate the exact degree of angle of the distortion, we have used here detectSURFfeature function (Detect Speeded-Up Robust Features (SURF) features in grayscale image). It also treats with outliers. Outliers are data values that deviate from the mean by more than three standard deviations. When estimating parameters from data containing outliers, the results may not be accurate. 'Sign of Laplacian' is a property unique to SURF detector. Blobs with identical metric values but different signs of Laplacian will differ by their intensity values: white blob on black background vs. black blob on white background. This value can be used to quickly eliminate blobs that don't match in this sense. For non-SURF detectors, this value is not relevant although it should be set consistently as to not affect the matching process. For example, for corner features, you can simply use the default value of 0. Note that SURFPoints is always a scalar object which may hold many points. Therefore, NUMEL (surf Points) always returns 1. This may be different from LENGTH (surf Points), which returns the true number of points held by the object. By using the Speeded-Up Robust Features (SURF) algorithm we find blob features in the previous step. These features are very important for the matching purpose. It extracts the featured value of the image which is found in both images. Now find out the index pair between these images. Table No 2: Matched Points (Input Image & Output Image) : SURFPoints Count Scale Location Metric 92 [92x1 single] [92x2 single] [92x1 single] Sign of Laplacian [92x1 int8] Orientation [92x1 single] Figure 7: Matched SURF points, including outliers ISSN: 2231-5381 http://www.ijettjournal.org Page 4 International Journal of Engineering Trends and Technology (IJETT) – Volume 18 Number1- Dec 2014 Figure 11: Same methodology (Geometric Transformation) applied on Reference Image-3 Figure 8: Matching inliers Now Recover the Image with the help of matching inliers. Figure 12: Same methodology (Geometric Transformation) applied on Reference Image-4 Figure 9: Recovered Image Figure 10: Same methodology (Geometric Transformation) applied on Reference Image-2 Figure 13: Same methodology (Geometric Transformation) applied on Real Image data III RESULT ANALYSIS ISSN: 2231-5381 http://www.ijettjournal.org Page 5 International Journal of Engineering Trends and Technology (IJETT) – Volume 18 Number1- Dec 2014 In Geometrical Transformation method the feature point in Original Image and the transformed image is calculated. By calculating the feature point only we avoid the huge calculation on each pixel, consequently reducing the time, effort and the complexity of the system. We analyzed in this algorithm all the perspective matching and extracting procedure and at the end calculated the PSNR and MSE value. The calculated PSNR value is resembled and up to the mark which is desirable. Now consider another fact. If image is first blurred and then led to face geometrical rotations then reconstruction of the Image becomes challenging, because here spatial coordinates of the pixels are also affected. Now the question is how to resolve this issue? Here practically by applying Geometrical method iteratively we found that blur has been removed and the desired value of PSNR and MSE has been achieved. Geometrical Transformation gives us the facility to extract the feature point in the image those feature points are nothing but the pixel which is found commonly at both Images. By applying the same method on the Reference and Real images the study has been carried out. IV.I Quality Measurements In order to evaluate the quality of watermarked image, the following signal-to-noise ratio (SNR) & MSE equation is used: Table No 4.4: PSNR and MSE value for various Images OR, Image PSNR Value (db) MSE Value Reference Image I 44.2836 0.0108 Reference Image II 46.6766 0.0094 Reference Image III 45.2553 0.0106 Reference Image IV 39.4302 0.0148 Real Image 43.4253 0.0121 Result for Geometric Transformation Algorithm (when the distance between pixels is constant but PSNR and MSE calculated by applying the Geometric the spatial location has been changed) Transform Algorithm at various Reference & Real Images. Result has been tabulated here in table number 3. Table No 3: PSNR & MSE value estimation Image PSNR Value MSE Value Reference Image I 42.3769 0.0144 Reference Image II 40.8362 0.0165 Reference Image III 43.8668 0.0124 Reference Image IV 38.0147 0.0171 Real Image 45.4133 0.0107 In the previous study we see that if all the geometric pixel location rotates by a particular angle while the distance between their neighbourhoods is constant, Real Image shows the better PSNR value with Least MSE. ISSN: 2231-5381 Figure 14: PSNR Vs MSE for different Image (when the distance between pixel is constant but the spatial location has been changed) http://www.ijettjournal.org Page 6 International Journal of Engineering Trends and Technology (IJETT) – Volume 18 Number1- Dec 2014 Result for Geometric Transformation Algorithm (when the distance between pixel & the spatial location both has been changed) Figure 15: PSNR Vs. MSE for different Image (when the distance between pixel & the spatial location both has been changed) By applying Geometric Transformation method we observe by study that it is very easy to implement, take less time than any algorithm & less complexity. It also gives desirable PSNR & MSE value. It is useful and compatible for gray scale image. V CONCLUSION Estimating the amount of blur in a given image is important for computer vision applications. More specifically, the spatially varying defocus point-spread-functions (PSFs) over an image reveal geometric information of the scene, and their estimate can also be used to recover an all-in-focus image. A PSF for a defocus blur can be specified by a single parameter indicating its scale. Most existing algorithms can only select an optimal blur from a finite set of candidate PSFs for each pixel. Some of those methods require a coded aperture filter inserted in the camera. In this thesis we used Geometric Transform Algorithm to estimate the feature point from the original and blur image. These featured points are further used for the restoration of the blur image or the image whose pixels coordinate value has been changed due to transformation or blur. By applying Geometric Transformation method we observe by study that it is very easy to implement, take less time than any algorithm & less complexity. It also gives desirable PSNR & MSE value. [1] Deepa Kundur, Student Member, and Dimitrios Hatzinakos, “A Novel Blind Deconvolution Scheme for Image Restoration Using Recursive Filtering ,” IEEE Transactions On Signal Processing, Vol. 46, no. 2, February 1998. [2] Xiumei Kang, Qingjin Peng, Gabriel Thomas and Yu, “Blind Image Restoration Using The Cepstrum Method” IEEE CCECE/CCGEI, Ottawa, May 2006. [3] Punam Patil & R.B.Wagh “Implementation of Restoration of Blurred Image Using Blind Deconvolution Algorithm” IEEE 2013. 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In International Conference on Computer Vision and Pattern Recognition (CVPR). IEEE, 2005. [20] A. Buades, C. Coll, and J.M. Morel, “A review of image denoising algorithms, with a new one. Multiscale Modeling and Simulation”, 4(2):490–530, 2005. Ankita Sharma is a Research Scholar at IASSCOM Fortune Institute of Technology affiliated to Rajiv Gandhi Proudyogiki Vishwavidyalaya, Bhopal. She is persuing her M.Tech in Digital Communication. She has keen interest to work on Image Processing. Uday Bhan Singh has received his degree in Electronics & Communication Engineering & Master’s in Nano Technology, presently working as HOD, Deptt. of Electronics & Communication at IASSCOM Fortune Institute of Technology affiliated to Rajiv Gandhi Proudyogiki Vishwavidyalaya, Bhopal. Ankur Chourasia has received his degree in Electronics & Communication Engineering and master’s in Digital Communication, presently working as an Assistant Professor in Deptt. Of Electronics & Communication Engineering at IASSCOM Fortune Institute of Technology affiliated to Rajiv Gandhi Proudyogiki Vishwavidyalaya, Bhopal. Author’s Profile ISSN: 2231-5381 http://www.ijettjournal.org Page 8