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Image Processing

What is Image Processing?

Image Processing is an action undertaken using sophisticated software, such as Erdas Imagine, PCI, ENVI and ER Mapper to alter digital images. These image processing software packages have extensive tools specifically designed to access and process multispectral, hyperspectral, radar and airbourne imagery.

Image processing involves the manipulation of the pixels of one image to form another image. Various operations may be performed on the pixels of the original image to produce the new image. These operations may be performed on each pixel in isolation or relative to other pixels in the image.

The purpose of image processing is:

  • to improve the visual appearance of images, or
  • to prepare images for measurement of features and structures present.

More specifically, image processing may be used to, for example:

  • clean up an image by removing noise
  • improve the contrast in an image
  • highlight elements with certain characteristics in an image
  • overcome distortions such as blurring or warping of an image caused by a camera or scanner
  • compensate for uneven illumination

Some basic image processing operations, which may be carried out, include:

  • filtering, which attempts to highlight significant features and suppress insignificant detail,
  • edge detectors, which highlight significant transitions and thus indicate boundaries within the image,
  • texture analysis, which identify variation in brightness from one pixel to the next or within a small region,
  • thresholding and segmentation, which attempt to separate an object from its background,
  • thinning, skeletonizing and distance transforms, which convert dominant shape features to economical, simplified representations,
  • histogram equalization, which produces an approximation to a uniform histogram for an image.

Landmap hosts a large resource of spatial data information and can provide advice on image processing software supported also by the Image Processing Course.