I am trying to organize my trading card collection digitally and am working on building a scanner using ocr to detect the names of my collection.
I need to use a webcam to snap a single image of each card in question. Snapping the image doesn't seem to be to difficult, but I need help determining how to get OpenCV to capture only a specific part of that image for OCR to work with. I'm trying to capture just the text portion of the image so that the artwork on the cards doesn't interfere with the OCR.
If my card will be placed in the same physical location each time, is there a way to get OpenCV to take an image and focus on just the area of the image that I'm interested in.
Thank You
Sour Jack
I am not sure I understand the problem. Do you want to use your OCR algorithm always on the same portion of the snapshot? If so, you can try something like:
roi = img[y:y+height, x:x+width]
There is more information here: http://answers.opencv.org/question/29260/how-to-save-a-rectangular-roi/
Related
I wanted to capture a pair of stereo images with my iPhone camera. I wanted to know how could I do it. What ai have tried so far is, clicked one photo moved my phone a little to the right (almost 1.5 inches), but I did not get the desired results.
I want to rectify those images before I could apply opencv's StereoBM_create function to them. But I can't capture proper stereo images.
I have been tasked to use OpenCV and C++
Read a set of videos for creating a set of images/learning.
Classify objects seen in the videos
Label the images
test against series of test videos to check objects were identified as expected. draw a rectangle around them and label.
I am new to OpenCV however happy to program in C++ as soon as approach is formed. I am also planning to write my own functions at a later stage.
I need your help in formning right way of solution approach as I have to identify household objects [cup, soft toy, phone, camera, keyboard) from a stream of video and then test on another stream of video. The original video has depth information as well but not sure how to use it to my benefit.
Read about Support vector machine (SVM) , Feature extraction (e.g. SIFT/SURF) , SVM training and SVM testing. And, for drawing Rectangle, read about findContour(), drawContour() in openCV.
Approach:
Detect objects (e.g. car/plane etc.). Store the points of its contours
Extract some features of that object using SIFT/SURF
Based upon the extracted features, classify the object using SVM (the input for SVM will be the extracted features)
And if the SVM says -Yes! it is a car. Then, draw a rectangle around it using the points of its contour which you had stored in first step.
I am developing a sample camera and I am able to control image sensor directly. The sensors gives out Bayer image and I need to do show images as live view.
I looked at debayering codes and also white balancing. Is there any library in C/C++ that can help me in this process?
Since I need to have live view, I need to do these things very fast and hence I need algorithms that are very fast.
For example, I can change the RGB gains on sensor and hence I need an algorithm that act at that level, instead of acting on generated image.
Is there any library that help to save images in raw format?
simplecv has a function for white balance control:
simplecv project web site
I am working on a project with gesture recognition. Now I want to prepare a presentation in which I can only show images. I have a series of images defining a gesture, and I want to show them in a single image just like motion history images are shown in literature.
My question is simple, which functions in opencv can I use to make a motion history image using lets say 10 or more images defining the motion of hand.
As an example I have the following image, and I want to show hand's location (opacity directly dependent on time reference).
I tried using GIMP to merge layers with different opacity to do the same thing, however the output is not good.
You could use cv::updateMotionHistory
Actually OpenCV also demonstrates the usage in samples/c/motempl.c
I'm building a web cam application as my C++ project in my college. I am integrating QT (for GUI) and OpenCV (for image processing). My application will be a simple web cam app that will access the web cam, show/record videos, capture images and other stuffs.
Well, I also want to put in a feature to add cliparts to captured images, or the streaming video. While on my research, I found out that there is no way we can overlay two images using OpenCV. The best alternative I was able to find was to reconfigure the whole image to add the clipart into the original image making it a single image. You see, that's not going to work for me as I have to be able to move the clipart and resize or rotate the clipart in my canvas.
So, I was wondering if anybody could tell me how to achieve the effect I want most efficiently.
I would really appreciate your help. The deadline for the project submission is closing in and its a huge bump on the road to completion. PLEEEASE... RELP!!
If you just want to stick a logo onto the openCV image then you simply define a region of interest (roi) on the destination video image and copy the source image to this (the details vary with each version of opencv)
If you want the logo to be semi transparent - like a TV channel ID - then you can copy the image but loop over the pixels writing a destination that is source_pixel/2 + dest_pixel/2;