I have already tried imfill(img) but that doesn't work at all.
I have noticed that imfill works for this purpose only for images in which the object's boundary is complete and not broken like the image i am taking .
For this particular image do the following:
Prepend a white row to the image to close the contour.
Fill the contour.
Remove the helper row.
Anything else requires more information and examples.
Matlab documentation states that "a hole is a set of background pixels that cannot be reached by filling in the background from the edge of the image". In this case any pixel can be reached from the edge because its boundary is not complete. Therefore, technically there is no hole in the image you posted.
Related
I am making a card recognition project on MATLAB and I am stuck at this point. There are images of cards and on an image I want to define the smallest rectangle that takes the card inside. Example like below
Original image
Converted image
I am currently able to convert the image to black and white (leaves me only the cards white spaces), I want to define the rectangles by the whole white spaces. E.g., if I have 3 non-lapping cards in my image, I want to have 3 images like above (doesn't matter if another cards edge appears on the image, the important part is that rectangle must pass through the edges of the selected card).
I have tried edge definition methods but wasn't successful. Thanks for your help already.
I recommend you use regionprops function from the image processing tool box, i.e.,
bb = regionprops(yourImage, 'boundingbox');
which will return the bounding box. There is a nice MATWORKS video here and you can jump to about minute 26 for what you need.
For Example, I have the below image used for demo purpose only
Fill close portion with pattern
if user tap on any part of T-Shirt, than T-Shirt should be filled with selected pattern image.
I have used to find an array of the point contains close area it takes time as well to find close region points and try to draw color at that points, but it takes too much time to draw because there are many points for the close region.
I have used code from below link
https://github.com/Chintan-Dave/UIImageScanlineFloodfill
This algorithm is actually for flood fill, but I have added one more method to collect all points to one NSSet.
A help is too much appreciated.
Thanks in advance.
I have an ellipse in the image.After segmentation i got a broken ellipse as shown .which morphological operation is used to get the perfect ellipse
Actual input file is
output obtained is
i tried imopen ,but i will lose lower ellipse like structure .how to close the upper ellipse like structure without losing lower ones
Mask i created is
i want to segment the ellipse like structure.but some of these structures are connected with rectangular like bodies.how to separate it. erode will eliminate small ellipses
If you want to reconnect something with a mathematical morphology operator, do not use an opening (it increases the gap), but a closing (imclose)! The names are explicits.
In you case, you want to reconnect something vertically cut, so use a horizontal structuring element (type segment).
And yes, you have to invert your image, black pixels representing the absence of information.
Usually, for closing gaps, you would need the close operator.
However, since most software assume active pixels are white, you would either need to invert the image, or use the open operator.
On this image, in matlab, the following works well:
imopen(I,ones(32))
This uses a square structuring element. You may want to experiment with other shapes.
Your example also looks like you moved half of the ellipse, as opposed to some process which deleted pixels in the middle. No simple morphological operation can create a perfect ellipse out of the sample image, unless you use the knowledge that multiple components can be moved to re-form the ellipse. If that is the actual case, you can scan connected components and try to match them together.
I have scanned copies of currency notes from which I need to extract only the rectangular notes.
Although the scanned copies have a very blank background, the note itself can be rotated or aligned correctly. I'm using matlab.
Example input:
Example output:
I have tried using thresholding and canny/sobel edge detection to no avail.
I also tried the solution given here but it detects the entire image for cropping and it would not work for rotated images.
PS: My primary objective is to determine the denomination of the currency. There are a couple of methods I thought I could use:
Color based, since all currency notes have varying primary colors.
The advantage of this method is that it's independent of the
rotation or scale of the input image.
Detect the small black triangle on the lower left corner of the note. This shape is unique
for each denomination.
Calculating the difference between 2 images. Since this is a small project, all input images will be of the same dpi and resolution and hence, once aligned, the difference between the input and the true images can give a rough estimate.
Which method do you think is the most viable?
It seems you are further advanced than you looked (seeing you comments) which is good! Im going to show you more or less the way you can go to solve you problem, however im not posting the whole code, just the important parts.
You have an image quite cropped and segmented. First you need to ensure that your image is without holes. So fill them!
Iinv=I==0; % you want 1 in money, 0 in not-money;
Ifill=imfill(Iinv,8,'holes'); % Fill holes
After that, you want to get only the boundary of the image:
Iedge=edge(Ifill);
And in the end you want to get the corners of that square:
C=corner(Iedge);
Now that you have 4 corners, you should be able to know the angle of this rotated "square". Once you get it do:
Irotate=imrotate(Icroped,angle);
Once here you may want to crop it again to end up just with the money! (aaah money always as an objective!)
Hope this helps!
I've converted a colored photo to black and white, and bolded the edges. Now i need to convert it back to its original color with the bolded edges. Is there any function in matlab which allows me to do so?
Once you remove the colour from an image, there is no possible way to automatically put it back. You're basically reducing a set of 16,777,216 colours to a set of 256 - on average each shade of grey has 65,536 equivalent colours, and without the original image there's no way to guess which it could be.
Now, if you were to take the bolded lines from your black-and-white image and paint them on top of the original coloured image, that might end up producing what you're looking for.
If what you are trying to do is to use some filter over the B/W image and then use that with the original color. I suggest you convert your image to a color space with Lightness channel that suits your needs (for example L*a*b* if you need the ligtness to be uniformly distributed regarding human recognition of differences) and apply your filter only over the Lightness channel.