Image Processing Paper Presentation h5032

IMAGE PROCESSING Presented By :Lovely Soni Chartered Institute of Technology, aburoad.

WHAT IS IMAGE ? Image is an Artifact that reproduce the likeness of some subjects usually a physical object.

IMAGE ENHANCEMENT  

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Improving Quality of Image Two types of Work Area: I) Special Domain II)Frequency Domain In Special Domain enhancement achieved by processing on the actual pixels of image. In Frequency Domain it is achieved by processing on a frequency or intensity.

HISTOGRAM    

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HISTOGRAM is graph of color intensity value v/s no. of pixels with that intensity in image. HISTOGRAM is Blueprint of image. How to construct HISTOGRAM? Working with RGB image of 24 bit image , HISTOGRAM is prepared for each color . Working with Grayscale image of 8 bit maximum 256 shades ,single HISTOGRAM is prepared.

FILTERS FILTERS FOR IMAGE PROCESSING:  Brightness Filter  Smoothing Filter  Noise Reduction Filter  Contrast Filter

Brightness Filter   

To increase BRIGHTNESS of image, move its HISTOGRAM towards high intensity. It is achieved by adding some fixed value in each pixels of image. It means HISTOGRAM is shifted by that value and BRIGHTNESS increased by the same.

BRIGHTNESS FILTER 

For eg.

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To increase BRIGHTNESS in RGB image, we have to add K value in each color that is, RED, GREEN & BLUE. Processed pixel= source pixel + Brightness constant

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Brightness Filter

Smoothing Filter  

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To apply SMOOTHNESS, mask of 9 pixels is used Target pixel

This mask is applied on all pixels to smooth image. To apply this mask we have to move from upper left corner to lower right corner one by one each pixel. The Target pixel is replaced by the MEAN of mask pixels.

Smoothing Filter

Noise Reduction Filter 

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In image any spike (point or itch) comes during scanning called NOISE. To remove NOISE, in some methods, mask of 5 pixels of “ + “ sign shape is used. Target pixel

This mask is applied on all pixels of image. Image results in reduced image or low noise image. To apply this mask we have to move this mask from upper left corner of image to lower right corner one by one on each pixel. The MEDIAN of mask pixels replaces the Target pixel.

Noise Reduction Filter

Contrast Filter 

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To increase CONTRAST of image, spread up its HISTOGRAM over X-axis. It means HISTOGRAM is spread up by a constant value and CONTRAST increased by the same. For eg. To increase CONTRAST in Gray image, for each pixels , we have to subtract mid intensity from pixel intensity then increase or decrease it by contrast constant and then add mid intensity value to it. Processed pixel = (source pixel-128) *(( contrastpercent+100)/100) +128

Contrast Filter

Operations Euclidean geometry transformation • Color correctness • Digital compositing • Image registration • Image recognition • etc… •

Applications Computer Vision • Face Detection • Feature Detection • Medical Image Processing • Remote Sensing • etc… •

Thank You….