Author:	Camillo Bosco (camillo.bosco@studenti.unict.it)
Advisor:	Prof. Sebastiano Battiato (battiato@dmi.unict.it)
History:	This plugin was implemented in July 2005
Works with:	8-bit images (grayscale and indexed) and RGB images
ImageJ's version:	1.33u (used to develop this plugin)
Source:	Contrast_Stretching.java
Installation:	Download Contrast_Stretching.java to the plugins folder and compile it with the "Compile and Run" command. Restart ImageJ to add the "Contrast Stretching" command to the Plugins menu.
Description:	This plugin implements the contrast stretching operator for image enhancement in the spatial domain. It allows to enhance contrast of low-contrast images increasing their dynamic range. User can choose his/her preferred transform function simply modifying the location of two control points (r1, s1) and (r2, s2) which allow to change the shape of the transformation. In particular if r1=s1 and r2=s2 the transformation is a linear function that produces no changes in input levels (identity transform). There is only one important constraint: r1<=r2 and s1<=s2. It means that the transform function must be monotonically increasing: this condition preventes the creation of intensity artifacts in the processed image. A particular case of contrast stretching operator is the thresholding operator: if r1=r2, s1=0 and s2=255 the thresholding function is obtained.
Usage:	Here is a brief description: 1) Change the control points (blu points) in order to create your favourite LUT; 2) If you want, click on the button "List" to view the LUT values; 3) Also the possibility to save the graph in GIF format is provided by clicking on the button "Save"; 4) Click on the button "Preview" to view as the image would be if it was processed according to the chosen transform curve; 5) Click on the button "Apply" to definitively apply the current transform to the image; 6) Click on the button "Help & Info" to view some information about this plugin.
Downloads:	Bosco C., A presentation of this project provided by C.Bosco (in Italian);
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