I am trying to detect an object in a video. i am using SURF as feature detection and descriptor extractor, and BRUTFORCE as matcher. i tested my work with faces, i captured a picture of me and when i run the camera and direct it toward me, my face gets detected and a rectangle is drawn around it. i tried to make another test, i captured an image of my mouse and resized it, and when i run the cam, it is not getting detected
the problems i am facing are:
1-is the size of the query/object image matters in such cases,? i am asking this question because the image i captured of my self is bigger than the one of the mouse, and the face is getting detected and the mouse not.
2-regardless of which image i am using as a query/object iamge, how to display camera preview of only the train/scene image without the query/object image. i am asking this question because, what i am getting is something as shown in the below posted images, while what i want to do is something as it is shown here, i checked the code in that link, it is in C++ but i followed the same thing and also the tutorial uses 'drawMatches' method which has a peer in java which is Features2D.DrawMatches() and both of them returns a Mat object with the query/object image on the left side and the train/scene image on the right side as also shown in the image i posted below.
what i want to do is, to display on the the camera output without the query/object image, i want the area designated for the camera output is to show only the train/scene image captured from the camera.
please let me know how to solve this issues, i want to do something as shown in the tutorial i cited in the link.
1 - size matters but in your case, I think the most crucial problem is "textureness". SURF detect the interest points where the "texture gradient" is strong. In the case of your mouse, the gradient is mainly smooth, except aroud the logo (fujitsu), the button and at the border of the image. In the tutorial you point to, you notice it uses a very textured object to demonstrate the effect.
2 - to the best of my knowledge, there is fully automatic method to do what you want, but it can be done with a few steps. Basically, you must determine the surrounding box of your object then draw it. To draw, the easier is to use cv::rectangle but you can be more precise with four (or more....) cv::line. To determine the surrounding box, you can estimate the extreme points among the filtered matches.
Good luck!
Related
Currently, I am doing Image COLOUR filtering operation second MEDIAN filtering then CANNY EDGE DETECTION ALGORITHM.
Then, I read pixels using for loop and I draw lines using pixel, but I do not getting proper result for palm scanning and showing lines on human Palm.
So if anybody has any types of idea regarding this then please let me know.
Currently i am getting this type of result:
but I need this type of output:
Oh I got your problem, You can do this by following steps.
1.process your hand image with canny edge detection algo lets name that cannyImage.
2.now create the bitmap of cannyImage and remove black pixels from the image and replace them with transparent pixels, black only because canny image will be filled with black color and objects lines in white when you process the image through the algo, now you have extracted the image with palm lines white in color, lets name that palmLineImage.
3.now the main part is MASKING you need to mask the palmLineImage on the original image.
These three steps will give you your desire O/P.
Tools you can use GPUImage awsesome library by BradLarson for this https://github.com/BradLarson/GPUImage2
For refining the palm image from background which I'm sure you have to use in future you can use GrabCut algo
LINK - https://github.com/naver/grabcutios
and now the apple has launched Photos captured in Portrait Mode on iOS 12 contain an embedded person segmentation matte that made it easy to create creative visual effects like background replacement.
Links - https://developer.apple.com/videos/play/wwdc2019/260/ , https://developer.apple.com/videos/play/wwdc2019/225/
Looks like you need to use something like the douglas peucker algorithm - to simplify the number of data points and smooth the lines. link - https://en.wikipedia.org/wiki/Ramer%E2%80%93Douglas%E2%80%93Peucker_algorithm
We are developing an app where we need to crop an image according to the selecting object area. User will draw a line and we need to select the object and crop it .This crop need to be like the app: YourMoji
So far we have tried to get the color of the pixels along the line and then comparing those with the color of every pixel in the image and making a path from it to clip the image. But the almost going no where.
Is it possible through this way to crop an image or we are going in the wrong way? Can anyone provide a way to do this Or suggest a way to modify the way we have worked so far? Any advice and suggestions will be greatly appreciated!
Thanks in advance.
I guess what you want is the image segmentation algorithm called Graph Cut.
Here are two Github repositories, hope these would help:
GraphCut
GrabCutIOS
I'm not exactly clued up on image manipulation, but the first algorithm that comes to mind is something like this:
Take the average of the pixels in the line (as you have)
Since you appear to want faces, you might want to weight reds and blues over green. Not much green in faces of any skin tone.
For each pixel, if the colour is within a given threshold outside of your selected average, remove it / make transparent.
Perhaps the closer to the original line (or centroid), the less strict the threshold becomes.
I'd then provide the user with some tools for:
Sensitivity: how large the threshold is
Eraser: to remove parts of the image that your algorithm missed
Paintbrush: to replace parts of the image that your algorithm incorrectly removed.
So to be simple I have a RenderTexture of another camera, and I need to overlay it onto another camera either through:
a) A RenderTexture of that camera
or
b) directly to the cameras rendering
What I'm trying to do can also be seen in this representation:
fig1 shows the main render, fig2 shows the desired overlay to be applied, fig3 shows them applied in a way of overlay, fig4 shows post processing of the now newly edited image
Where the first box is the main camera, and the second is what I want overlayed onto it as a RenderTexture in OnRenderObject() A.K.A when these two get rendered. Then in OnPostRender() these are combined where the overlay will be ontop. Then in OnRenderImage(), image effects can freely change the combined images together.
So as a list of what I need help with in explaining is that:
I do not know how to either:
Access the cameras rendering directly
or
Set a RenderTexture as a cameras rendering in OnPostRender()
I also need help though explanation in correctly overlaying a RenderTexture onto either one of the above (This would be using the depth rendered to the RenderTexture as alpha) just as shown in fig3 of the image.
This is the method I've thought up in order to overlay a forward rendering onto deferred for image effects. If you have any other solutions or ideas, it'd be very well appreciated if you could post them as a comment.
Just to clarify I'm not asking for source code, just methods and or links to Unity3D's documentation of said methods that I'm asking about.
Thank you very much so in advance. :)
I am using 4-Way floodfill algorithm.
I have a transparent image with black out line.
That is staring point image(without color).
And after filling the color in this image it look like this
Please help me and let me know what can i do for proper fill.
I used and implemented myself FloodFill in other projects and the algorithm goes trough the whole draw, looking for closed spaces and then draw inside (or outside) them.
Your problem happens with every tool in the world that fills a draw, and the problem is the same, the spaces are not 100% closed.
The floodfill algorithm goes pixel by pixel and when it detect a black pixel, it stops. For example, the arm of the scuba driver is not thick enough or it has holes on it, and the flood fill algorithm manages to go trough it and not detect it as an empty space.
Nobody here can tell you why unless we take your project and analyse it, so the best I can offer is a guideline about where your error could be.
I tried the code with an image that has a very precise defined border around it (from here) and it seems to work OK with that image. I suggest perhaps that if you zoom into your image that there is some grey aliasing around the edges which won't get filled. Perhaps the algorithm has a threshold function that can be tweaked?
Try setting the andTolerance value (I tried 4 which seemed to improve my example).
//Call function to flood fill and get new image with filled color
UIImage *image1 = [self.image floodFillFromPoint:tpoint withColor:newcolor andTolerance:4];
I am working on OCR recognition App and I want to give the user the option to manually select the area (during the camera selection) on which to perform the OCR. Now, the issue I face is that I provide a rectangle on the camera screen by simply overriding the - (void)drawRect:(CGRect)rect method, However, despite there being a rectangle ,the camera tries to focus on the entire captured area rather than just within rectangle specified.
In other word, I do not want the entire picture to be send for processing but rather only the part of the captured image inside the rectangle. I have managed to provide a rectangle, However with no functionality. I do not want the entire screen area to be focused, but only the area under the rectangle.
I hope this makes sense since i have tried my best to explain it.
Thanks and let me know
Stream the camera's image to a UIScrollView using an AVCaptureOutput then allow the user to pinch/pull/pan the camera into the proper place... now use UIGraphics Image Context to take a "screen-shot" of this area and send that UIImage.CGImage in for processing.