create program in java to draw lines on image

I'm searching for a program that allows creating colored String Art Portrait similar to the ART NITKA's ones, the idea is to have a Java or Groovy function. INPUTS -------------- - an image (JPG or PNG) - a boolean that indicate if it is a circle or a rectangle - width and height or radius - the number of points at the border - the number of lines - the list of lines's colors OUTPUT -------------- and return a list of [startPosition, endPosition, color], without jump from a line of a color and the next of the same one (there is a single uncut path for each color). Then i need also a simple interface to select the data, the image and see the result of the colored lines overlap (The interface is only to evaluate the result, later I'm going to put the java/groovy portion in another custom project)