Develop Reference

Barrel distortion effect for image (JavaFX)

I'm looking for some way to set background image with barrel distortion effect(FishEye/FOV) for node using JavaFX. I found algorithm with pixel manipulation, but I want to find some another way(some hack) for reach it. This effect will be use for create node background high definition image changing animation(animation wil be change factor(power/value/degree?)) of this effect.

I'd like to offer an alternative approach which is much more efficient (real-time capable). Any solution which is based on direct pixel manipulations is doomed to be very inefficient especially for a "high definition image".
Instead I'd propose to use a TriangleMesh for this and use the image as its texture. You can then apply any kind of distortion you like by just manipulating the texture coordinates. This approach can be easily integrated into any 2D graphics via the JavaFX scene graph.
I am actively using this concept for on-the-fly reprojection of raster map tiles, so I know it works.

I will answer this question in the spirit that it was asked, i.e. no code.
JavaFX has an effect framework.
There is no in-built fisheye effect.
You could create your own custom fisheye effect implementation and plug it into the effect framework if you are a skilled developer.
Easier would be to apply your algorithm using a WritableImage with a PixelWriter or Canvas. Perhaps that could even plug into the effect framework (if you actually needed to do that, which you probably don't) using an ImageInput.
For an example of applying an algorithm to the pixels in an input image see:
Reduce number of colors and get color of a single pixel
Of course, you would use a fisheye algorithm (coded for JavaFX instead of the linked implementations) for a fisheye transform.
To animate use an AnimationTimer or, again for skilled developers, create a custom transition that plugs into the JavaFX animation framework.
You can add properties to your custom effect and manipulate them using additional properties defined on the custom transition you create.
Providing a complete solution is out of scope for a StackOverflow answer. To get help with individual tasks, split the problem up into different pieces, e.g. creating a custom effect, manipulating pixels to create a fisheye, animating an effect on an image or timeline, etc. Write the code and ask questions about the actual code with a minimal example for the problem portion you are trying to solve when you get stuck.

Manipulating Pixels(Drawing) in Java

This is not a typical "what library do i use?" or "is there an API for that". Using lines of code I create not implementing them through a library of sorts. Is there any documentation on how to actually create a window, and within that window draw a line from pixels?
I just want to understand how its done, and not learn through a library which does it for me.
Previously tried:
JavaFx
Swing

If you want to draw a line in a window, you'll ultimately have to create a BufferedImage, set pixels in that BufferedImage according to some drawing algorithm (like Bresenham's), then put the BufferedImage in the window.

Java image library - turn grid image into array

If I have an image of a table of boxes, with some coloured in, is there an image processing library that can help me turn this into an array?
Thanks

You can use a thresholding function to binarize the image into dark/light pixels so dark pixels are 0 and light ones are 1.
Then you would want to remove image artifacts using dilation and erosion functions to remove noise (all these are well defined on Wikipedia).
Finally if you know where the boxes are, you can just get the value in the center of each box to determine the array value, or possibly use an area near the center and take the prevailing value (i.e. more 0's is a filled in square, more 1's is and empty square).
If you are scanning these boxes and there is a lot of variation in the position of the boxes, you will have to perform some level of image registration using known points, or fiducials.
As far as what tools to use to do this, I'd recommend first trying this manually using a tool like ImageJ, which has a UI and can also be used programatically since it is written all in Java.
Other good libraries for this include OpenCV and the Java Advanced Imaging API.
Your results will definitely vary depending on the input images and how consistenly lit and positioned they are.
The best way to see how it will do for your data is to try applying these processing steps manually to see where your threshold value should be, how much dilating/eroding you need to get consistent results.

How should I proceed to do a interactive program with drag feature and graph arrows

I'm doing a college project which I must finish in 3 months. And I have 8 hours a week to spend in that project.
The project consists in doing a graphical interface that shows many rectangles next to each other which should be movable. It should be very similar to the tabs in the chrome browser, where you can drag them to which ever position you want.
In addition to that there should be arrows connecting one rectangle to the other. And these arrows should still connect the same rectangles even when I change the order of the rectangles. The image below illustrates what I'm saying.
The image shows before and after one of the rectangles being dragged.
Since Java is my first language, I would like to use it.
My question is: What framework, APIs should I use to do this project. What will be the easiest and fastest way to do it? Should I use Swing? or JavaFX? or GWT? or other alternative?
Is there an API for handling arrows connecting objects? Maybe one used for representing graphs may be ok.
Edit: I don't know anything about Swing and neither about JavaFX. So which one would be more worthwhile learning given that I don’t have too much time this semester because I’m very busy?

This shouldn't be too hard to write from scratch.
Use this site : http://www.codeproject.com/Articles/116088/Draggable-Components-in-Java-Swing for the drag-able components
Draw arrows with some kind of parameterization (math formula) for half of an oval. Pass the draw path into a java.awt.Graphics2D pen object.

You might want to check Java Universal Network/Graph Framework.
It has some extensive support for making editable graphs while maintaining relationship among nodes and edges.
What you can do is change the icon of node to a squared rectagnle, while add logic to plot them in a straight axis so that it would look the way you want, plus it would be editable while linked arrows will remain where they should be.
But incase you don't have experience with Swing, better start learning the basis of SWING first, as JUNG framework pretty much requires some good basic knowledge of swing itself.

Advice needed: A programmatic way for creating vector graphics with heavy usage of text

I need a way for render a tree-like structures, similar to flowcharts.
Surprisingly, I can't find(or I'm doing wrong) a suitable tool.
First, I looked at SVG. But I couldn't find a way to draw a bounding box around the text
without using ECMAScript: I tried to do a simple thing drawing two text surrounded by boxes and linked by a line, centered by sides(some thing like O-O, where O is a box with text).And when you use ECMAScript, you heavily limit the tools that can be used for SVG rendering(for example you can't convert corrently such SVG to png or pdf with ImageMagick).
Second, I tried Asymptote, but it is quite heavy when you start manipulating with text(you need an LaTeX system installed and configured).
I look for a tool in which you can:
Programmatically access to font properties: baseline, ascent, descent, height
Computing height/width of a string(or the bounding box)
basic vector graphics functionality like drawing lines, shapes etc.
I don't think that's a hard stuff. For example, all such functionality exists for example in Java2D. Sure, I can use it as last resort and get raster graphics, but may be there is something handy to use?

Have you looked at GraphViz (http://www.graphviz.org/)? It does not really match your requirements since you give up some control and instead let the tool do the layout and rendering based on a declarative a description of a graph or tree, but I have found it to be the easiest way to generate tree-like output.

Not sure if it should be free?
Here's a commercial solution with an extensive API
http://www-01.ibm.com/software/integration/visualization/java/