How to display a value from a variable into a textbox

if true
  % code
global citra
global tampung
I = rgb2gray(citra);
BW = tampung;
      BW = im2bw(BW);
      s = regionprops(BW, I, {'Centroid','WeightedCentroid'});
numberOfBlobs = size(s, 1);
labelShiftX = -7; %untuk mengkondisikan posisi titik tengah.
      titikX = [1 2 3 4];
      titikY = [1 2 3 4];
end
hold on
      numObj = numel(s);
      for k = 1 : numObj
      plot(s(k).WeightedCentroid(1), s(k).WeightedCentroid(2), 'r*');
      titikX(k)=s(k).WeightedCentroid(1);
      plot(s(k).Centroid(1), s(k).Centroid(2), 'bo');
      titikY(k)=s(k).WeightedCentroid(2);
      end
      hold off

        Xmtkaki = (titikX(1)-titikX(4));
        Ymtkaki = (titikY(1)-titikY(4));

        Xmtkika = (titikX(4)-titikX(1));
        Ymtkika = (titikY(4)-titikY(1));

        Xmtkamu = (titikX(1)-titikX(2));
        Ymtkamu = (titikY(1)-titikY(2));

        Xmtkimu = (titikX(4)-titikX(2));
        Ymtkimu = (titikY(4)-titikY(2));

        Xmtkahi = (titikX(1)-titikX(3));
        Ymtkahi = (titikY(1)-titikY(3));

        Xmtkihi = (titikX(4)-titikX(3));
        Ymtkihi = (titikY(4)-titikY(3));

I want to display value from this variable (Xmtkaki, Ymtkaki) to a text box, but i didn't know how to display it.

need u'r help

thanks in advance.

Answer 1

[Walter Roberson]

Let position1 and position2 each be (different) 4-element position vectors reflecting the location and size of the two text boxes. For example, [0 0 .1 .05]

The next two lines only need to be done once, to create the text boxes.

textbox1 = uicontrol('Style', 'text', 'Units', 'norm', 'Position', position1);
textbox2 = uicontrol('Style', 'text', 'Units', 'norm', 'Position', position2);

Then, each time you want to update the boxes,

set(textbox1, 'String', num2str(Xmtkaki));
set(textbox2, 'String', num2str(Ymtkaki));

[Lidank Abiel]

how to know pixel value on that coordinate ?

[Walter Roberson]

You make up values depending on where you want the boxes to be positioned in the figure.

[Image Analyst]

If you know the centroid, you can simply get the gray level of the original image at that centroid (or weighted centroid) location. Just be aware that the centroid is (x,y), NOT (row, column) so you need to get the graylevel as

grayLevelAtCentroid = yourImage(centroidY, centroidX);

By the way, did you run my demo (linked in my comment in my answer)? It puts a text string at the location of the centroid of each blob, and marks each centroid and weighted centroid with a "+" symbol.

[Lidank Abiel]

did u mean this sir ?

thisBlobsPixels = blobMeasurements(k).PixelIdxList;

[Image Analyst]

No, PixelIdxList is the list of linear indexes of the pixels, whereas PixelList is their gray levels.

Answer 2

[Image Analyst]

You probably want to call impixelinfo() (in the Image Processing Toolbox). This will give live, updated x,y,gray level information to a text box on the screen (that you can position wherever you want).

[Lidank Abiel]

I mean sir, how to know pixel value from titikX and titikY [1] ?

[Image Analyst]

I don't know what they represent. Perhaps you need to run my image segmentation tutorial http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862, where I find object and their centroids and label them on the image.