image-processing

问题 I’m currently working on an image registration algorithm which uses aerial imagery. My objective is to compute the percentage of overlap between two images as shown below. Visually the images have about 50% overlap, I'm using OpenCV following this implementation and this formula, the registered images are warped making it's implementation tricky. A similar implementation with a different formula can be found here. Are there any simpler workarounds to just find a rough estimate of the overlap?

问题 I'm trying to allow a user to upload a file using a form, then the image is supposed to be handled using multer in my controller file. For some reason, when I use upload.single('foobar'), it's coming back as "undefined," and screwing up the rest of my application. Specifically, when I run the code, my error handler in the createTour.js file returns an alert that reads "Cannot read property 'imageCover' of undefined". Any help would be appreciated. If helpful, here's the GitHub. Here's the

问题 I'm trying to allow a user to upload a file using a form, then the image is supposed to be handled using multer in my controller file. For some reason, when I use upload.single('foobar'), it's coming back as "undefined," and screwing up the rest of my application. Specifically, when I run the code, my error handler in the createTour.js file returns an alert that reads "Cannot read property 'imageCover' of undefined". Any help would be appreciated. If helpful, here's the GitHub. Here's the

问题 I have a function that reads map tile images. I want to keep track of whether or not a certain image has already been cached. I'm using this function from this thread: function is_cached(src) { var image = new Image(); image.src = src; return image.complete; } This was working great. But then I needed to do some image processing. In order to copy the image data to a canvas and process it pixel by pixel, I need to use CanvasRenderingContext2D.drawImage(image, 0, 0) . But it bugs me with a

问题 Using Opencv.js I have acquired the contours in an image. using some selection function I have collected a subset of these contours. Say they are in the list of contours: var suitableContours = []; I need to know draw these contours using opencv. If this were python I could do cv.drawContours(img, [suitableContours[cnt]], 0, [255, 0, 0, 255], 2); Assume by the point I want to draw the contours I don't have access to the original image nor the mask nor the original contour list, only the

问题 Using Python I am trying to convert each pixel of a B/W image to hex and store it in a '.txt' file. I have to use C for my application so its easier to read from a text file then do the entire conversion in C code. I have tweaked some example code from online, but I am still not very experienced with using Python. When I run my python script it only produces two hex values instead of eight. At first I thought this was from the image being B/W, but an RGB image should contain 0x000000 for

问题 The Fourier transform of the convolution (with stride 1) of two images is equivalent to point-wise multiplication of their individual Fourier transforms. I need to perform stride-'n' convolution using the above FFT-based convolution. For some reasons I need to operate in the frequency domain itself after taking the point-wise product of the transforms, and not come back to space domain by taking inverse Fourier transform, so I cannot drop the excess values from the inverse Fourier transform

问题 The Fourier transform of the convolution (with stride 1) of two images is equivalent to point-wise multiplication of their individual Fourier transforms. I need to perform stride-'n' convolution using the above FFT-based convolution. For some reasons I need to operate in the frequency domain itself after taking the point-wise product of the transforms, and not come back to space domain by taking inverse Fourier transform, so I cannot drop the excess values from the inverse Fourier transform

问题 Using Opencv.js I have acquired the contours in an image. using some selection function I have collected a subset of these contours. Say they are in the list of contours: var suitableContours = []; I need to know draw these contours using opencv. If this were python I could do cv.drawContours(img, [suitableContours[cnt]], 0, [255, 0, 0, 255], 2); Assume by the point I want to draw the contours I don't have access to the original image nor the mask nor the original contour list, only the

问题 Really I'm trying to apply 3X3 Median Filtering by C# and depending on my understanding the concepts of Median Filtering I wrote the following code but when I'm running it the Form hangs. I think have some problem in the last nested for loop but i don't know where is the error or the wrong in applying the Median concepts! public static Bitmap MedianFiltering(Bitmap bm) { List<int> termsList = new List<int>(); Bitmap res, temp; Color c; int counter = 0; //Convert to Grayscale for (int i = 0; i