How to add text to an image

Hello, If I have an image with the size 512*512 (or any other size) how do I add a string to any location I choose for example location (100,250) all the codes I found are too long but is there a one line code that does this?

Answer 1

[Image Analyst]

You can do it with a function in the Computer Vision System Toolbox. If you don't have that, you'll have to use this from Brett Shoelson: http://www.mathworks.com/matlabcentral/fileexchange/38721-embed-text-and-graphics-in-an-image

[John Snow]

I found the thing I was looking for "text" but I still have a problem when I type >> text (84,145,'random') The result is good and shows in image however my code has certain parameters and in those parameters there is a calculation which results in LAX = 82 LAY = 145 so when I type>> text (LAX,LAY,'random') the matlab gives me the following error (Error using text Invalid parameter/value pair arguments) How to make the (text) order read LAX,LAY results in a way that doesnt give error?

[Image Analyst]

You're not telling me the whole story. This works just fine:

grayImage = imread('cell.tif');
imshow(grayImage);
axis on;
LAX = 82;
LAY = 145
text(LAX, LAY, 'random')

[John Snow]

the code is too long to post here about 1000 lines and you are right it does work when you put it like this but in the calculation in the original code it doesn't here is the part of the code

 LAX = (LeftX + RightX) / 2
    LAY = (LeftY + RightY) / 2
text (LAX,LAY,'random');

It calculates these numbers but gives me an error as shown

[Image Analyst]

You must have overwritten text with something else. Before the text line, put this

which -all text
whos text

tell me what it says

[John Snow]

It said the following

built-in (C:\Program Files\MATLAB\R2011b\toolbox\matlab\graph2d\text) Error using text Invalid parameter/value pair arguments

Error in fayezcode (line 83) text (LAX,LAY,'random');

[Image Analyst]

That doesn't make any sense. It looks like it's the normal built in text() function. What happens if you put this line right before that line

text(82, 145, 'random2');
theUnits = get(gca, 'Units') % See if it's normalized, pixels, or whatever.

Does that work? Does it display the 'random2' text without complaining?

[John Snow]

Yes it shows random2 perfectly and says the following

theUnits =

normalized

[Image Analyst]

You can't have numbers more than 1 if the units are normalized. OK, what does this do:

text(.4, .5, 'random');

[John Snow]

It works but puts the text on the very top-left corner of the image

[Image Analyst]

If you want to work with pixels then try setting the units property to pixels instead of normalized.

[John Snow]

(error using set invalid handle) I did the following - It still doesnt work

      LAX = (LeftX + RightX) / 2
      LAY = (LeftY + RightY) / 2
      set (LAX,'units','{pixels}');
      set (LAY,'units','{pixels}');
      text(LAX, LAY, 'random');

[John Snow]

Hello I found a solution that worked I converted to binary then from binary to dec again by adding this

    LAX = dec2bin(LAX);
    LAX = bin2dec(LAX);
    LAY = dec2bin(LAY);
    LAY = bin2dec(LAY);

It worked for some reason so the problem is solved for me but if there is a better solution I will keep my eyes on this topic thank you very much for all your help

[Image Analyst]

That's nonsense. You don't set the units property of a scalar variable to anything. LAX and LAY don't even have properties like 'units'! You set the units property of an axes or figure to something.