MATLAB: Correlation between ‘FontSize’ for “insertText” function and resulting letter/textbox height in pixels

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What is the correlation between 'FontSize' for "insertText" function and resulting letter/textbox height in pixels?

 I would  like to specify the size of the letters in pixels. For instance, I want the Letter 'A' to be x pixels high. I do not know how to achieve this using the 'FontSize' parameter as the correlation between the font size and the letter/textbox height in pixels is unknown. For instance what does 12 point font equal in pixels for the "insertText" function?

Best Answer

The "insertText" function uses TrueType fonts to render the text. TrueType is software that is embedded in both Windows and Mac operating systems and is outside of MATLAB. Currently there is no way for "insertText" to request the font height in pixels using the underling rendering library. However, once the font is rendered, the "insertText" function will "know" the font height in pixels but this value is currently inaccessible from outside the function.

As a workaround, you can measure the number of pixels of the output text to get the relationship between font height in pixels and the font size.

The workaround steps are as follows:

1. Select whatever string you wish to render.

2. Set the 'BoxOpacity' parameter of "insertText" to 1 to see the background box.

3. Use "imtool" function to measure the height of the box. "imtool" doc is linked below:

https://www.mathworks.com/help/releases/R2018a/images/ref/imtool.html

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MATLAB: How to display a MATLAB table in a figure and make it bold

To display a table in a figure, see the following MATLAB Answers post, which outlines two methods, one using "uitables" and another printing the Command Window output as an "annotation" with TeX Markup on the figure:

     <https://www.mathworks.com/matlabcentral/answers/254690-how-can-i-display-a-matlab-table-in-a-figure>

If you then want to make the data in the table itself appear bold (not just the columns header), try the following for the two methods described in the above link:

1) With uitables, you can format individual cells using "uistyle" objects, then add that format to the table with the "addStyle" function:

     <https://www.mathworks.com/help/matlab/ref/uistyle.html?s_tid=doc_ta>
     <https://www.mathworks.com/help/matlab/ref/matlab.ui.control.tableappd.addstyle.html?s_tid=doc_ta>

2) If you are using an annotation with TeX Markup to display the Command Window output of the table, add your "\bf" and "\rm" tags to the beginning and end of your text, respectively. This will make all text appear bold. Below I have edited the code block from the MATLAB Answers post linked above,

% Create table

LastName = {'Smith';'Johnson';'Williams';'Jones';'Brown'};

Age = [38;43;38;40;49];

Height = [71;69;64;67;64];

Weight = [176;163;131;133;119];

T = table(Age,Height,Weight,'RowNames',LastName);

% Get the table in string form.

TString = evalc('disp(T)');

% Use TeX Markup for bold formatting and underscores.

TString = strrep(TString,'<strong>',''); %these tags are now redundant

TString = strrep(TString,'</strong>',''); %these tags are now redundant

TString = strrep(TString,'_','\_');

TString = ['\bf' TString '\rm']; %add bold markup tags to beginning and end of text

% Get a fixed-width font.

FixedWidth = get(0,'FixedWidthFontName');

% Output the table using the annotation command.

annotation(gcf,'Textbox','String',TString,'Interpreter','Tex',...

    'FontName',FixedWidth,'Units','Normalized','Position',[0 0 1 1]);

MATLAB: How to prevent axes clipping when changing zoom on a tall image

There are two possible solutions to this issue, one using Image Processing Toolbox and one with base MATLAB.

Image Processing Toolbox - Image Viewer app:

The Image Viewer app (which can be opened via the "imtool" function) that comes with the Image Processing Toolbox has the desired zooming behavior. It can be used as follows:

im = imread('TallSkinny.png');  % Plots your image
imtool(im);

When zooming, the width of the tall image will expand to fill the figure. Here is a link to the documentation about "imtool" and the Image Viewer app:

https://www.mathworks.com/help/releases/R2016b/images/ref/imtool.html

Base MATLAB - No Axes Clipping:

In base MATLAB, you can change the Axes properties for "DataAspectRatioMode" and "Clipping" to achieve the desired behavior:

I = imread('TallSkinny.png');
imshow(I)
ax = gca;
ax.DataAspectRatioMode = 'manual';
ax.Clipping = 'off';

This should yield similar zooming behavior as does the "imtool" solution. Here is a link to the documentation about Axes properties:

https://www.mathworks.com/help/releases/R2016b/matlab/ref/axes-properties.html

Best Answer

Related Solutions

MATLAB: How to display a MATLAB table in a figure and make it bold

MATLAB: How to prevent axes clipping when changing zoom on a tall image

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