insert text into videos from 4 different folders containing *png files

I would like to generate videos from 4 different folders, which are "CamPersp_kurzDach", "CamPersp_sDach", "CamX", "CamY"

and i would like also to add the text containing the filename information into the videos.

i have tried the following code. Which doesn't work for 4 folders, but only 2 folders.

and the text which I added, does't work.

by the way, i don't have library which support inserttext

clc
clear all
 cd CamPersp_kurzDach
 FIR = dir('*.png');
 cd ..
 cd CamPersp_sDach
 FOR = dir('*.png');
 cd ..
cd CamX
 FIR1 = dir('*.png');
 cd ..
 cd CamY
 FOR1 = dir('*.png');
 cd ..

v1 = VideoWriter('output.avi');
open(v1);

for kk = 1:min(numel(FIR),200) % loop through the first 200 png files
    filePath_IR = fullfile(FIR(kk).folder,FIR(kk).name);
    filePath_OR = fullfile(FOR(kk).folder,FOR(kk).name);
    filePath_IR1 = fullfile(FIR1(kk).folder,FIR1(kk).name);
    filePath_OR1 = fullfile(FOR1(kk).folder,FOR1(kk).name);
    %I = imread(filePath);
    %writeVideo(v,I);
    F_IR = imread(filePath_IR1);
    F_OR = imread(filePath_OR1);
    F_IR = imread(filePath_IR1);
    F_OR = imread(filePath_OR1);
    if kk == 1 
        size_OR = size(F_OR,[1,2]); 
    end
    F_IR = imresize(F_IR,size_OR); % <- Added this line
    F_OR = imresize(F_OR,size_OR); % <- Added this line
    bothImages = [F_IR, F_OR];
    
    figure;
    imshow(bothImages);
    % add the filename as text to the image
    %textImg = insertText(bothImages,[10 10],FIR(kk).name, 'FontSize',18,'BoxColor','white','BoxOpacity',0.7);
    [filepath,name,ext] = fileparts(FIR(kk).name);
    textString = strcat('time=', num2str(str2num(name)/1000),'s');
    position = [10 10];
    fontSize = 18;
    color = [100 100 100]/255;
    boxColor = [0 0 0];
    boxOpacity = 0.7;
    text(position(1),position(2),textString,'FontSize',fontSize,'Color',color,'BackgroundColor',boxColor,'Margin',1);
    


hFrame = getframe(gca); %// Get content of figure

%imwrite(hFrame.cdata,'MyImage.tif','tif') %// Save the actual data, contained in the cdata property of hFrame
imwrite(bothImages,strcat(fullfile(FIR(kk).folder,name),'_new.tif'));
    writeVideo(v1, bothImages);    
close all    
    
end

close(v1);

Answer 1

[DGM]

There are a number of other tools on the File Exchange for inserting text into images or for creating text images which can then be composited with an image.

https://www.mathworks.com/matlabcentral/answers/101413-how-can-i-add-text-to-an-image-and-make-the-text-become-part-of-the-image-within-matlab#answer_747078

It depends what sort of properties you want (colors, font face, size, antialiasing). Few of the tools provide antialiasing, and getting both FG/BG coloring will probably require an extra compositing step beyond what the example shows.

For reasons of fidelity and consistency, I'd personally avoid figure capture if at all possible.

[yijun guo]

the problem is, that i don't have inserttext function

[DGM]

I know. I don't either. The link I gave demonstrates two methods. The first is a modification of the problematic technique proposed by the official answer in that thread. The second relies on freely available tools from the FEX and basic logical image composition. I included links to various such tools and mentioned some of their strengths and weaknesses.

For example. This uses MIMT textim() to generate the text image and replacepixels() to do the compositing.

inpict = imread('peppers.png'); % an RGB image (uint8)

% create text mask
thistext = sprintf('Frame %04d',123); % however you want
tmask = textim(thistext,'wyse-700b'); % gray, binarized (double)

% text props
offset = [80 20]; % offset from Nw corner [y x]
fgcolor = [1 0.5 0];
bgcolor = [0.5 1 1];
bgalpha = 0.3;

% construct fg image to insert
FG = replacepixels(fgcolor,bgcolor,tmask); % RGB (double)

% define ROI and extract BG region
sz0 = size(inpict);
szt = size(tmask);
yrange = offset(1)+(1:szt(1));
xrange = offset(2)+(1:szt(2));
BGroi = inpict(yrange,xrange,:); % RGB (uint8)

% composite text image and sampled BG region
BGroi = replacepixels(FG,BGroi,bgalpha+tmask); % RGB (uint8)

% assemble the final image
outpict = inpict;
outpict(yrange,xrange,:) = BGroi;

% write it or display it or something
imwrite(outpict,'op.png')

I didn't need to draw the image to a figure or use inserttext() or any special toolbox functions. The only thing I needed was something from the File Exchange.

The text is placed oddly only because I wanted it to have something behind it to more clearly show that the text has a solid foreground (orange) but a semitransparent background (teal). MIMT textim() does support other fonts, but they're all bitmapped legacy hardware fonts, so this might not suit your needs. The other FEX text-image tools have different capabilities.

The compositing could be done otherwise, but it would complicate the example. I've posted lots of examples, but if you were to use textim(), you'd also have replacepixels().

[DGM]

As to the code not working,

% you get four file paths
filePath_IR = fullfile(FIR(kk).folder,FIR(kk).name);
filePath_OR = fullfile(FOR(kk).folder,FOR(kk).name);
filePath_IR1 = fullfile(FIR1(kk).folder,FIR1(kk).name);
filePath_OR1 = fullfile(FOR1(kk).folder,FOR1(kk).name);
% ...
% but you only use two
% these assignments are redundant
F_IR = imread(filePath_IR1);
F_OR = imread(filePath_OR1);
F_IR = imread(filePath_IR1);
F_OR = imread(filePath_OR1);

[DGM]

FWIW, MIMT now has a higher level convenience tool for doing this. See puttext()

inpict = imread('peppers.png'); % an RGB image (uint8)

% get whatever text
thistext = sprintf('Frame %04d',123); % however you want

% text props
gravity = 'nw'; % the reference location from which to offset
offset = [80 20]; % offset from Nw corner [y x]
fgcolor = [0 1 0.5]; % tuples can be I/IA/RGB/RGBA
bgcolor = [0.5 1 1 0.3];
font = 'wyse-700b'; % same fonts used by textim()

% assemble the image
outpict = puttext(inpict,thistext,'font',font,'offset',offset,...
            'fgcolor',fgcolor,'bgcolor',bgcolor,'gravity',gravity);

% show it
imshow2(outpict,'invert')

It basically does the same composition as described before.