kopfbild

Image analysis of slates

introduction & software

The image analysis comprises the acquisition and processing of images followed by the measurement and evaluation of objects of interest. In reality infinite nuances of colour exist which also can be described as continuous or analogous data. Because computers cannot process this large amount of data, this analogous data has to be turned into discrete numbers. This transformation is called digitalization and is a prerequisite for the image analysis. Digitalization can be achieved by different methods and are always related with a loss of image information.

After the digitalization an image consist of a matrix of quadratic picture points which are described as pixels. With this pixels one has all image information in a form of quantitative data. Based on this, the phenomena of interest such as mica layer or grains can be measured and calculated.

Software

The shareware GraphicConverter was used for first general image operation. Which software one uses is more a personal choice because most of the free application offer sufficient functionality for the demands of image enhancement. Yet it is very useful if several processing steps can be carried out at once, saving a lot of time.
The image analysis was realized by the freeware Image SXM, which is a modification of the the freeware NIH IMAGE by the U.S. National Institute of Health. Both process only images with grey values. GraphicConverter, IMAGE SXM and NIH Image run under Mac OS9 and Mac OSX.

An alternative freeware is ImageJ which was written in Java and runs under Mac OS 9/X, Linux and Windows and can also be downloaded on the website of the U.S. National Institute of Health. Here one can find all information about the software and their handling. A great advantage of ImageJ is the availability of a plenty of free plugins for different purposes.

home | about me | contact | downloads | links