Image processing is the process of performing some operations
on an image in order to improve pictorial information of the image for human
interpretation and processing of image data for storage, transmission and
representation for autonomous machine perception. As an example one of the
image processing technique is changing brightness and this can be make the
image visually pleasing for humans or make the image suitable to use in a
computer vision application.
For this process image is an input and output may be image
or characteristics / features associated with that image. There are two types
of methods used for image processing.
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Analogue image processing
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Digital image processing
Analogue image processing
Analog images are the type of images that we as humans look
at. What we see is various level of brightness and colors and it is not broken
into many small individual pieces. Image
analysts use various fundamentals of interpretation while using these visual
techniques. In another word this processing refers to the alteration of image through electrical means. As an example television image. The television signal is a voltage level which varies in amplitude to represent brightness through the image. By electrically varying the signal, the displayed image appearance is altered. Further followings are some examples for analogue images.
Photographs, paintings, TV images, medical images
recorded on film or displayed on various display devices.
Digital image processing
A digital image is a matrix of many small elements, or
pixels. Each pixel is represented by numeric value. In general, the pixel value
is related to the brightness or color that we will see when the digital image
is converted into an analog image for display and viewing.
Digital image processing techniques help in manipulation of
the digital images by using computers.
For this process all images undergo in three steps,
- Pre processing.
- Enhancement.
- Display and information extraction.
figure 1 : Comparison between analog and digital images
Analog image processing-
ReplyDeleteIn electrical engineering and computer science, analog image processing is any image processing task conducted on two-dimensional analog signals by analog.
In analog wave formats that can be named as analog image.
As an example, television broadcasting through the dish antenna system.
Digital image processing-
Use of computer algorithms to perform image processing on digital images.
It allows a much wider range of algorithms to be applied to the input data and can avoid problems such as the build-up of noise and signal distortion during processing
Ohhh new topic analog image processing...thanks for highlighting...
DeleteCan anybody elaborate about how analog image processing perform... i mean how image is formed through analog image processing
ReplyDeleteA new method of two-dimensional image processing by analog techniques is introduced.
ReplyDeleteThe original image stored on a film is re-scanned by a flying spot scanner with a special raster,so-called omnidirectional scanning, by which
the film is scanned in any direction with constant speed and with uniform scan-line density.The extracted image information is fed through an electronic filter to a display CRT. The asymmetric impulse response of the filter can be canceled out by superposition of video signals in all directions on the screen of the CRT. Therefore two-dimensional image processing can be accomplished with the one-dimensional filter.
The preliminary processor was constructed and tested for phantom images obtained with a scintillation camera.