Re: Direction indicator

Posted by Rasband, Wayne (NIH/NIMH) [E] on
URL: http://imagej.273.s1.nabble.com/Direction-indicator-tp3686815p3686816.html

On Sep 14, 2010, at 4:50 PM, Michael Doube wrote:

> Dear all,
>
> I'm thinking about implementing a direction indicator to show the
> orientation of the body that the image is from.  I mainly work with
> anatomy, so the anatomical directions (medial, lateral, dorsal, ventral
> etc.) are most interesting, but there's nothing stopping it from showing
> compass directions (north, south, east, west) or anything else.
>
> One way around this might be to rotate the image, but this would mean
> interpolating pixels, which is bad.
>
> My ideal would be to have a cross with text labels at the ends, that you
> can move by grabbing the centre or rotate by grabbing the ends.  You
> could also change the labels with a right click or a menu item
> somewhere.  A bit like the zoom indicator but interactive.  It would
> also have to exist without interference from ROIs or fiddling about with
> the ROI Manager.
>
> I had a go at doing this with Line and TextRoi, and the Overlay class
> but only succeeded at showing the lines and text boxes; I couldn't grab
> the handles and it behaves like an ROI by disappearing...
>
> Any hints at how to achieve this better would be appreciated,

Take a look at the internal Orthogonal_Views plugin (Image>Stacks>Orthogonal Views). The source code is at

      http://imagej.nih.gov/ij/source/ij/plugin/Orthogonal_Views.java

It use overlays and the ImageCanvas.setCustomRoi() method to create custom cross-shaped selections on XY, YZ and XZ views.

-wayne

> Abortive attempt follows...
> ---------------------------
> package org.doube.geometry;
>
> import java.awt.Color;
> import java.awt.Font;
> import java.awt.Graphics;
>
> import ij.ImagePlus;
> import ij.gui.Line;
> import ij.gui.Overlay;
> import ij.gui.Roi;
> import ij.gui.TextRoi;
>
> /**
>  * Indicator to show anatomic directions such as medial, proximal, cranial
>  *
>  * Instantiate 2 line ROI's, lock their lengths, lock their midpoint to
> always
>  * be the same position.
>  *
>  * @author Michael Doube
>  *
>  */
> @SuppressWarnings("serial")
> public class AnatomicAxes {
>
> private static final String[][] axisLabels = { { "medial", "lateral" },
> { "cranial", "caudal" }, { "rostral", "caudal" },
> { "dorsal", "ventral" }, { "anterior", "posterior" },
> { "superior", "inferior" }, { "proximal", "distal" },
> { "dorsal", "palmar" }, { "dorsal", "plantar" },
> { "dorsal", "volar" }, { "axial", "abaxial" } };
>
> /** Common midpoint */
> private int x, y;
>
> /** Axis length */
> private int length;
> private ImagePlus imp;
> private Line line1, line2;
>
> /** TextRoi labels for axes */
> private TextRoi tr1, tr2, tr3, tr4;
>
> private Graphics g;
> private Overlay overlay;
>
> public AnatomicAxes(ImagePlus imp) {
> this.imp = imp;
> int w = imp.getWidth();
> int h = imp.getHeight();
> this.length = Math.min(w, h) / 4;
> this.x = w / 2;
> this.y = h / 2;
> this.line1 = new Line(x, y - length, x, y + length);
> this.line2 = new Line(x - length, y, x + length, y);
> TextRoi.setFont("SansSerif", 10, Font.PLAIN, true);
> this.tr1 = new TextRoi(x, y - length - 10, axisLabels[0][0]);
> this.tr2 = new TextRoi(x, y + length + 10, axisLabels[0][1]);
> this.tr3 = new TextRoi(x - length - 10, y, axisLabels[1][0]);
> this.tr4 = new TextRoi(x + length + 10, y, axisLabels[1][1]);
> this.overlay = new Overlay();
> overlay.add(line1);
> overlay.add(line2);
> overlay.add(tr1);
> overlay.add(tr2);
> overlay.add(tr3);
> overlay.add(tr4);
> for (Roi r : overlay.toArray()){
> r.setImage(this.imp);
> }
> overlay.setStrokeColor(new Color(0, 0, 255));
> this.imp.setOverlay(overlay);
> this.g = this.imp.getCanvas().getGraphics();
> create();
> }
>
> public void create() {
> for (Roi r : overlay.toArray())
> r.draw(this.g);
> }
>
> public void reflect() {
> // TODO method stub
> // get whichever line is selected
> // swap the labels
> }
>
> }