wk 7.1 Flashcards
how does image blur happen
- camera vibration causing all image pixels to be affected
- movement by the camera or subject during image capture process
what is image blur
reducing edge content and making transition from one colour to another very smooth.
types of image blur
optical, motion
what filters can be applied to an image to blur it
average filter, weighted average filter, Gaussian filter & motion filter.
Gaussian Filter benefits
Provides gentler smoothing & preserves edges better than a similarly sized mean filter
Low Pass Filtering info
Spatial Low Pass Filtering:
- basis for most smoothing methods. image smoothed by decreasing disparity between pixel values by averaging nearby pixels
Gaussian Filter use
- Used to remove noise, also detail ie. blurs/smoothens the edges
Deblurring objective
recover original, sharp image by using a mathematical model of the blurring process
Low Pass Filtering cons
low pass filter tends to retain low frequency information within an image while reducing the high frequency information.
Deblurring formula
g(x,y) = h(x,y)* f(x,y) + η(x,y)
blurred image = Point Spread Function * Sharp Image + Additive Noise
What is deblurring
Deblurringis removing blurring artifacts fromimages.
Image deconvolutioninfo
image-processingtechnique designed to remove blur and enhance contrast and resolution.
MATLAB uses deconvwnr() that will deblur an image using Wiener filter algorithm.
side effects of high pass filtering
looses a large portion of visual information by filtering out low spatial frequency components.
Signal to Noise Ratio (SNR) will be reduced.
