I have to count the characters that is printed in a beverage tin[1]. So far i have done till removing noise and unwanted pixels and now my text is clear to read 2 but is there any way to count them properly. Ocr fails to detect this text. Or should i join these dots using some algorithm and continue with ocr function?
ROI of image
Here is the code which gave me the above picture.
clear all; close all;
a=imread('coke.jpg');
gray=rgb2gray(a);
thres=150;
lbw=double(gray>thres);
imwrite(lbw,'--\OCR\output.png');
a=imread('output.png');
c=imresize(a,.5);
b = im2bw(c, .9);
b=imcomplement(b);
imwrite(b,'compli.png');
You should definitely join the dots. The first thing I would try is the imclose function, which does morphological closing (dilation followed by erosion).
For example, you could try this:
im = imread('dotMatrix.png');
im2 = imclose(im, strel('line', 5, 90));
im3 = imclose(im2, strel('line', 5, 45));
Related
Could you please advice how can I implement morphological closing by reconstruction in Matlab?
As i know imreconstruct command can be used to implement opening by reconstruction (below my code for Opening by reconstruction).
img = rgb2gray(imread("input.jpg"));
img = imcomplement(img);
se=strel("square", 40);
marker= imerode(img,se);
mask=img;
opn_recon=imreconstruct(marker,mask);
Below is the code I wrote for Closing Reconstruction:
%Closing by reconstruction
img = rgb2gray(imread("input.jpg"));
img = imcomplement(img);
se=strel("square", 40);
marker= imdilate(img,se);
tmp=0;
while 1
marker_loop = marker;
geodesic=max(marker_loop,img);
recon=imerode(geodesic,se);
if isequal(recon,tmp)==1
break
end
tmp = recon;
marker = imdilate(marker_loop,se);
end
But code does not work properly. Could you please advice whats my mistake, so i can fix it?
imreconstruct applies an inf-reconstruction, which can be interpreted as the repeated dilation conditioned by a second image (mask). Because it's a dilation, it can be applied after a structural erosion to form an opening (opening by reconstruction).
To form a closing by reconstruction, we need to apply a dilation followed by a sup-reconstruction. The sup-reconstruction is the dual of the inf-reconstruction, and can therefore be interpreted as the repeated erosion conditioned by a second image. Being the dual, we can implement the sup-reconstruction in terms of the ind-reconstruction by inverting the image, applying the operation, and then inverting the result:
out = imcomplement(imreconstruct(imcomplement(marker), imcomplement(mask)));
Thus, the closing by reconstruction is:
img = imread('cameraman.tif');
se = strel('square', 40);
marker = imdilate(img,se);
mask = img;
cls_recon = imcomplement(imreconstruct(imcomplement(marker), imcomplement(mask)));
i'm am very new to Matlab but really want improve. For my experiment i want to show a picture which the participant response yes/no to, using two different keys (f&g) and then the next picture is presented and it repeats so onward.
Presenting the picture, using the keys works for far, but i can't get it to repeat the trial. Thus my question is how can i get the program to repeat/loop my trial?
Is there something wrong in my code so far or is there additional coding i should use?
this is my code so far
function try1_6()
cleanupObj= onCleanup(#() myCleanupFxn);
% PRETEST
% Initialize screen with black background
winID = Screen('openWindow',0, [0 0 0]);
%Parameter
backcol=255;
textcol=0;
% Load image file(s)
structimages= [];
TheImagesdir = dir('theImagesdir/*.jpg');
for i=1: length(TheImagesdir);
TheImages = imread(['theImagesdir/' TheImagesdir(i).name], 'JPEG');
% Get width and height
imageX = size(TheImages,2);
imageY = size(TheImages,1);
% Convert to texture
myTexture = Screen('MakeTexture', winID, TheImages);
% Set destination rectangle
destRect = [50 100 50+imageX 100+imageY];
%save to structure
structimages(end+1).filename=TheImagesdir(i).name;
structimages(end).destRect= destRect;
structimages(end).texture= myTexture;
end
%Make triallist
numberOfItems= [5]; %list of all possible items
Nrepeats=4;
Response=0;
TrialList=HH_mkTrialList({numberOfItems Response},Nrepeats);
%PRESENTATION
for trialnum=1:size(TrialList,1)
nitems = TrialList(trialnum,1);
Screen('FillRect', winID,backcol); % makes the screen blank
%displays text
DrawFormattedText(winID,'dkjfghaslkdfglksdjgfh','center','center',textcol);
Screen('Flip', winID)
HH_waitForKeyPress({'space'}); % waits for spacebar to be pressed
Screen('FillRect',winID,backcol);
Screen('Flip',winID);
WaitSecs(1);
%display picture
whichTheImages= randi(length(TheImagesdir)); % randomly selects image for directory
Screen('FillRect',winID,backcol);
Screen('DrawTexture', winID, myTexture, [], destRect);
Screen('Flip', winID);
HH_waitForKeyPress({'f','j'},5)
if resp==-1
break
end
TrialList(trialnum,4)= response; %records response
end
end
function myCleanupFxn()
Screen('CloseAll')
end
There are a number of problems with you code that you need to address. First of all, TrialList is used before it is declared/initialized. The Make triallist block of code seems out of place in the body of the for loop, and should probably be placed before you loop TrialList.
Your second problem is the inner for loop that loads images. Right now, it loads every image found in the directory, on every trial! There is no reason for you to be doing this, and you should be placing this for loop outside the trial loop as well. Furthermore, your original code never worked as intended, because you never save the loaded texture anywhere; myTexture is overwritten by the last image in your folder and that's the only texture you're ever gonna get. So in addition to pre-loading the images before the loop, you need to save them in a data structure so that you can use them later in your trial loop. A simple struct will work nicely here:
structImages = [];
TheImagesdir = dir('theImagesdir/*.jpg');
for i = 1:length(TheImagesdir);
TheImages = imread(['theImagesdir/' TheImagesdir(i).name], 'JPEG');
% Get width and height
imageX = size(TheImages,2);
imageY = size(TheImages,1);
% Convert to texture
myTexture = Screen('MakeTexture', winID, TheImages);
% Set destination rectangle
destRect = [50 100 50+imageX 100+imageY];
%save to structure
structImages(end+1).filename = TheImagesdir(i).name;
structImages(end).destRect = destRect;
structImages(end).texture = myTexture;
end
There are other inconsistencies in your code:
whichTheIamges is defined but not used
resp is used in the comparison if resp==-1 but is not defined
response is saved into TrialList before it is defined
Finally, the biggest problem is Screen('CloseAll', winID); is inside the trial loop, so you tear down your whole presentation platform after the first trial.
FYI, as noted in my comment wrapping your entire script in a try block is really poor practice. I suspect you do this because you want to be able to Ctrl+C mid-task, but there's a better way to do this. If you make your entire script a function then you can use the onCleanup method to execute code whenever your function exits (whether normally, by error, or by interruption). The method goes like this:
function myScript()
%//make your script a function. There is an additional advantages to doing this:
%//function performance is better than script performance.
%//blah-blah-blah
%//setup the cleanup object before opening screen
cleanupObj = onCleanup(#() myCleanupFxn);
%//open the screen
winID = Screen('openWindow',0, [0 0 0]);
%//blah-blah-blah
end
function myCleanupFxn()
%//local function, not visible outside of this file
Screen('CloseAll');
end
I am pretty new to Matlab and encountered a problem when working with images.
I want to get a pixel that is in a specific colour (blue) in the following image:
image
My current code looks something like this:
function p = mark(image)
%// display image I in figure
imshow(image);
%// first detect all blue values higher 60
high_blue = find(image(:,:,3)>60);
%cross elements is needed as an array later on, have to initialize it with 0
cross_elements = 0;
%// in this iteration the marked values are reduced to the ones
%where the statement R+G < B+70 applies
for i = 1:length(high_blue)
%// my image has the size 1024*768, so to access the red/green/blue values
%// i have to call the i-th, i+1024*768-th or i+1024*768*2-th position of the "array"
if ((image(high_blue(i))+image(high_blue(i)+768*1024))<...
image(high_blue(i)+2*768*1024)+70)
%add it to the array
cross_elements(end+1) = high_blue(i);
end
end
%// delete the zero element, it was only needed as a filler
cross_elements = cross_elements(cross_elements~=0);
high_vector = zeros(length(cross_elements),2);
for i = 1:length(cross_elements)
high_vector(i,1) = ceil(cross_elements(i)/768);
high_vector(i,2) = mod(cross_elements(i), 768);
end
black = zeros(768 ,1024);
for i = 1:length(high_vector)
black(high_vector(i,2), high_vector(i,1)) = 1;
end
cc = bwconncomp(black);
a = regionprops(cc, 'Centroid');
p = cat(1, a.Centroid);
%// considering the detection of the crosses:
%// RGB with B>100, R+G < 100 for B<150
%// consider detection in HSV?
%// close the figure
%// find(I(:,:,3)>150)
close;
end
but it is not optimized for Matlab, obviously.
So i was wondering if there was a way to search for pixels with specific values,
where the blue value is larger than 60 (not hard with the find command,
but at the same time the values in the red and green area not too high.
Is there a command I am missing?
Since English isn't my native language, it might even help if you gave me some suitable keywords for googling ;)
Thanks in advance
Based on your question at the end of the code, you could get what you want in a single line:
NewImage = OldImage(:,:,1) < SomeValue & OldImage(:,:,2) < SomeValue & OldImage(:,:,3) > 60;
imshow(NewImage);
for example, where as you see you provide a restriction for each channel using logical operators, that you can customize of course (eg. using | as logical OR). Is this what you are looking for? According to your code you seem to be looking for specific regions in the image like crosses or coins is that the case? Please provide more details if the code I gave you is completely off the track :)
Simple example:
A = imread('peppers.png');
B = A(:,:,3)>60 & A(:,:,2)<150 & A(:,:,1) < 100;
figure;
subplot(1,2,1);
imshow(A);
subplot(1,2,2)
imshow(B);
Giving this:
So, as I browse through google on the problem of how to create a .gif animation from series of .fig files, i stumble through one that uses .sdf file, I tried to rewrite the program to work for my .fig files
clear all;
close all;
dynam = 156;
gif_fps = 24;
video_filename = 'A.gif';
fh = figure(1);
for i = 1:dynam
F_data = getdata(['F' num2str(i,'_%03i', '.fig');
imagesc(F_data);
drawnow;
frame = getframe(fh);
im = frame2im(frame);
[imind,cm] = rgb2ind(im,256);
if a == 0;
imwrite(imind,cm,video_filename,'gif', 'Loopcount',inf);
else
imwrite(imind,cm,video_filename,'gif','WriteMode','append','DelayTime',1/gif_fps);
end
end
so it pops up an error saying
??? frame = getframe(fh);
|
Error: The expression to the left of the equals sign is not a valid target for an assignment.
which I don't understand why this is happening, and I also notice that Matlab is not drawing the figs, the figure that pop us is completely blank.
The error comes from a typo. The line
F_data = getdata(['F' num2str(i,'_%03i', '.fig'); %bracket missing at the end
should read
F_data = getdata(['F' num2str(i,'_%03i', '.fig']);
Without the bracket, Matlab sees
['F' num2str(i,'_%03i', '.fig');
imagesc(F_data);
drawnow;
frame
as a single string of letters. The code's logic is therefore a = b = c and matlab can't interpret this.
To prevent such errors, matlab and its editor have some nice coloring schemes that highlight in dark red the text following an opening string ', and turn the full string in purple when a closing ' is used. If you see some red characters spanning over several lines, that's a sign of a potential problem. Unfortunately, brackets don't have such behavior...
Additionnaly, what about opening the figures per se? You will see if each figure renders well (no blank) and will be able to capture the frame.
for i = 1:dynam
%open, get the frame from and close the figure
fh_tmp = open(['F' num2str(i,'_%03i', '.fig'])
frame = getframe(fh_tmp);
close(fh_tmp);
im = frame2im(frame);
...
I still struggle to find where the getdata is coming from.
I am looking for a code to insert characters into image with matlab.
The img is my cover image and msg is my text. I get this error
Error using ==> bitset
Operands to BIT Ops must be numeric.
But mine is numeric. It is not? How do I make it clear?
clear all;
img=imread('img.jpg','jpg');
msgopen=fopen('ramz.txt');
msg=fread(msgopen);
msgbin=dec2bin(msg);
msgsize=size(msg);
x=msgsize(1);
msgsizebin=dec2bin(x,8);
imgh=size(img,1);
imgw=size(img,2);
for i=1:imgh;
for j=1:imgw;
img(i,j)=bitset(img(i,j),msgbin(i,1));
end
end
You can use the text function and then the hardcopy function to create the image with the text coded into the data;
img=imread('img.jpg','jpg');
msgopen=fopen('ramz.txt');
msg=fread(msgopen);
hfig=figure;
imshow(img);
hold on;
text(x_loc,y_loc,msg); %x_loc and y_loc are the locations where you want the text to
% appear. msg is assumed to be a string.
orig_mode = get(hfig, 'PaperPositionMode');
set(hfig, 'PaperPositionMode', 'auto');
img_with_text = hardcopy(hfig, '-Dzbuffer', '-r0');