matchtemplate

OpenCV match template only on a specified grid of positions

由 六月ゝ 毕业季﹏ 提交于 2021-01-29 00:50:29
问题 I have a program where I get one image as input and I have to compare it with ~640 known images to see which one is the most similar. To do this I was thinking of using OpenCV's match template, as it seems very fast and effective in doing what I want to do. I noticed that matching two images, both 400x240 px, 1000 times is much slower than matching a 400x240 px image in a 1400x240 px, despite both of them being 1000 matches. My idea was to combine the 640 images in one big image containing

OpenCV match template only on a specified grid of positions

由 橙三吉。 提交于 2021-01-29 00:37:26
问题 I have a program where I get one image as input and I have to compare it with ~640 known images to see which one is the most similar. To do this I was thinking of using OpenCV's match template, as it seems very fast and effective in doing what I want to do. I noticed that matching two images, both 400x240 px, 1000 times is much slower than matching a 400x240 px image in a 1400x240 px, despite both of them being 1000 matches. My idea was to combine the 640 images in one big image containing

Matching template images with masks using OpenCV and C++

由 Deadly 提交于 2019-12-25 02:11:56
问题 How can I match a masked image using matchTemplate() in OpenCV with C++? This is my masked template image: And this is my source image: 回答1: Look at opencv example. You gotta call the matchTemplate function: matchTemplate( img, templ, result, match_method ); 回答2: matchTemplate 's fifth argument is a mask array which you can use for this purpose. In your case, you'll want a binary mask. That is, a Mat with: depth CV_8U , and dimensions equal to your template image, and the pixels you want to

Using opencv matchtemplate for blister pack inspection

由 删除回忆录丶 提交于 2019-12-20 10:13:51
问题 I am doing a project in which I have to inspect pharmaceutical blister pack for missing tablets. I am trying to use opencv's matchTemplate function. Let me show the code and then some results. int match(string filename, string templatename) { Mat ref = cv::imread(filename + ".jpg"); Mat tpl = cv::imread(templatename + ".jpg"); if (ref.empty() || tpl.empty()) { cout << "Error reading file(s)!" << endl; return -1; } imshow("file", ref); imshow("template", tpl); Mat res_32f(ref.rows - tpl.rows +

Explaing Cross Correlation and Normalization for openCV's Match Template

由 纵然是瞬间 提交于 2019-12-20 09:45:19
问题 My boss and I disagree as to what is going on with the CV_TM_CCORR_NORMED method for matchTemplate(); in openCV. Can you please explain what is happening here especially the square root aspect of this equation. 回答1: Correlation is similarity of two signals,vectors etc. Suppose you have vectors template=[0 1 0 0 1 0 ] A=[0 1 1 1 0 0] B =[ 1 0 0 0 0 1] if you perform correlation between vectors and template to get which one is more similar ,you will see A is similar to template more than B

emgu finding image a in image b [duplicate]

由 雨燕双飞 提交于 2019-12-18 11:55:44
问题 This question already has answers here : opencv finding image cordinates on another image (3 answers) Closed 6 years ago . I'm new to emgu and would like some advice on where to start. I've looked through the shape detection but its far too complex for what i need .. i think.. and my surfexample isn't working. I get this error: Cannot get SURF example in EMGU.CV to work? Anyway, this is what i would like to do: Find image A in image B. Image A is a simple square which always has the same grey

Success of template-matching with opencv

由 ℡╲_俬逩灬. 提交于 2019-12-11 05:24:17
问题 How do I measure success of the opencv template-matching algorithm ? I understand that the minmaxLoc function can be used to find the location of the best match. But does it also give an indication on how good the match actually was ? (If yes, how would you find out ?) Is there an even more appropriate function to measure the correlation between the found match (green rectangle) and the original template ? For example, what if the template-image is slightly rotated or translated compared to

Explaing Cross Correlation and Normalization for openCV's Match Template

由 倖福魔咒の 提交于 2019-12-02 19:45:14
My boss and I disagree as to what is going on with the CV_TM_CCORR_NORMED method for matchTemplate(); in openCV. Can you please explain what is happening here especially the square root aspect of this equation. Correlation is similarity of two signals,vectors etc. Suppose you have vectors template=[0 1 0 0 1 0 ] A=[0 1 1 1 0 0] B =[ 1 0 0 0 0 1] if you perform correlation between vectors and template to get which one is more similar ,you will see A is similar to template more than B because 1's are placed in corresponding indexes.This means the more nonzero elements corresponds the more

python opencv cv2 matchTemplate with transparency

由 风流意气都作罢 提交于 2019-11-30 05:34:14
问题 OpenCV 3.0.0 added the ability to specify a mask while performing templateMatch. When I specify a mask I get this error: error: (-215) (depth == CV_8U || depth == CV_32F) && type == _templ.type() && _img.dims() <= 2 in function matchTemplateMask Template image (PNG with transparency): Source image: Code # read the template emoji with the alpha channel template = cv2.imread(imagePath, cv2.IMREAD_UNCHANGED) channels = cv2.split(template) zero_channel = np.zeros_like(channels[0]) mask = np.array

emgu finding image a in image b [duplicate]

由 删除回忆录丶 提交于 2019-11-30 05:09:16
This question already has an answer here: opencv finding image cordinates on another image 3 answers I'm new to emgu and would like some advice on where to start. I've looked through the shape detection but its far too complex for what i need .. i think.. and my surfexample isn't working. I get this error: Cannot get SURF example in EMGU.CV to work? Anyway, this is what i would like to do: Find image A in image B. Image A is a simple square which always has the same grey 1 pixel border and always the same size (i believe) but the inner colour could be black or one of about 7 other colours
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