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DESIGNING AND MAKING OF NOISE REDUCTION APPLICATION USING IMAGE MORPHOLOGY. by : Dionisius Kristal / 26406061. Preliminary. The image result from the digital camera is not suit with the expected result. The camera that produces image with a little noise is very expensive.
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DESIGNING AND MAKING OF NOISE REDUCTION APPLICATION USING IMAGE MORPHOLOGY by : Dionisius Kristal / 26406061
Preliminary • The image result from the digital camera is not suit with the expected result. • The camera that produces image with a little noise is very expensive. • Some people develop algorithms to eliminate the noise (called noise reduction).
Previous Work • In 1986, Sternberg introduced the idea of noise reduction by repeatedly opening and closing with an increasing structuring elements size. • Song and Delp in 1990, discovered a technique they called "generalized morphological filter". However, use of structuring elements must be precise so that results can be maximized.
Theory • Image Processing Digital image processing is a discipline that studies matters relating to improvement of image quality. • Morphology Morphology is the science of form and structure. It is about regions or shapes, how they can be changed and counted, and how their areas can be evaluated.
Theory • Dilation to expand/grow
Theory • Erosion to reduce/shrink
Theory Dilation Erosion EXPANDED REDUCED
Theory • Opening (Erosion, then Dilation)
Theory • Closing (Dilation, then Erosion)
Theory The Sum of (Original Image – Result Image)^2/(width*height)^2 • Peak Signal to Noise Ratio Peak^2 is the peak pixel value between two images. RMSE is square root of MSE.
Theory What is Noise Reduction? Noise Reduction is program/system that has ability to reduce the (image) noise. Original Image Result Image
Theory Noise Reduction using Mathematical Morphology? • “Noisy” image = clean image + noise • Segment into features andnoise(the residual image). • Residual image = the difference between an original image and smoothed version. • The features from residual image will be added back to the smoothed image. • The results is an image whose edges and other one dimensional features are as sharp as the original one, but has smooth regions between them.
How it works? • The process is divided by 2 processes : smoothing process, and detail recovery. • Smoothing process is OCCO filtering (morphologycal opening-closing-closing-opening) • Detail recovery process is TOPBOT filtering (Tophat and Bothat) where Tophat is a positive residual image and Bothat is a negative residual image. • The output of TOPBOT filtering is Tophat and Bothat accumulation, where in this case, Tophat and Bothat accumulation is clean from noise.
How it works? The final result : “Clean” image = Tophat Accumulation + OCCO Image – Bothat Accumulation
How it works? OCCO image Tophat Accumulation Bothat Accumulation “Clean” image = Tophat Accumulation + OCCO Image – Bothat Accumulation
How it works? OCCO image
How it works? Final Result
Flowchart (main) OCCO filtering Tophat filtering Bothat filtering Final Summary
Flowchart OCCO O=OPEN(I) OC=CLOSE(O) C=CLOSE(I) CO=OPEN(C) OCCO image = ½ (OC+CO)
System Design and Application • 3 modules of the program are : • Load Module opening an image • Noise Reduction Module processing the noisy image • Save Image Module saving the image processing result.
Experiment • High ISO images are shot with ISO 400 and ISO 800 • Then those images are being processed with the program and Photoshop • The image results will be compared with Low ISO image and there will be a number that indicate the PSNR score
Experiment There are 6 categories of image : • Image with small particle object (Kopi.jpg, Komputer.jpg, Tombol.jpg) • Image with bright object and dark background (Pasir.jpg, Beras.jpg) • Image with letter (Box.jpg, Majalah.jpg, Notes.jpg, Koran.jpg) • Image with certain pattern (Lemari.jpg, Jeans.jpg, Batik.jpg) • Face Image (Wajah1.jpg, Wajah2.jpg) • Image with Noise Generator added on it
Conclusion • The score difference between the program and Photoshop are not too far. It means, the output of the program is similar to Photoshop has. • The program does not process the “small particle” image too well because there are detail from the image (which is very small) that lost. (Ex: Kopi.jpg) • The program consumes high resources and takes a long time. The program runs about 3 minutes for each repetition • The repetition maximum amount is 3, otherwise the result image will be blurred.
Conclusion (cont.) • Image resolution also affects the result image. The result of low resolution image will be more blurred (compare to the high resolution image). • There are several types of images that are not suitable to use skeletonize process due to the residues that are not accurate and the effectiveness of time.