hsv

问题 Could someone please help me with this function? This function is inside of a camera app that uses a filter algorithm to detect differences in colour variants etc. The syntax is very difficult for me. I don't know how to deal with the pointers in the arguments, the min and max variable syntax, what is delta etc? Could someone please translate for me? Much appreciated. Also should I be doing something with UIColor? Someone mentioned it below. I have no idea how to convert though. // r,g,b

问题 I want to find the HSV value of a LASER dot using opencv and python. I got the code http://opencv-srf.blogspot.com.au/2010/09/object-detection-using-color-seperation.html from here but it is in c++, installing visual studio and opencv takes time so i changed the code in python import cv2 import numpy as np def callback(x): pass cap = cv2.VideoCapture(0) cv2.namedWindow('image') ilowH = 0 ihighH = 179 ilowS = 0 ihighS = 255 ilowV = 0 ihighV = 255 # create trackbars for color change cv2

问题 I do not know how the following two formulas are derived. Please kindly explain. My reputation point is so low that I can't ask the person who wrote the formula. HSV triangle in C# var sat = (1 - 2*y1) / (sqrt3*x1 - y1 + 2); var val = (sqrt3*x1 - y1 + 2) / 3; 回答1: After the transformation, I needed the corners of the triangle to touch the unit circle at the points <0,-1> "top", <-√3/2,1/2> "bottom-left" and <√3/2,1/2> "bottom-right". I picked bottom-left to be the black point ( val = 0), and

问题 I have written a small Matlab funcion which takes an image in RGB and converts it to HSV according to the conversion formulas found here. The problem is that when I apply this to a color spectrum there is a cut in the spectrum and some values are wrong, see images (to make the comparison easier I have used the internal hsv2rgb() function to convert back to RGB. This does not happen with Matlabs own function rgb2hsv() but I can not find what I have done wrong. This is my function function [ I

问题 I am using openCV 3.1.0 (I have tried with 2.4.9, with same problem). I want to output a HSV mat to jpeg: // .. Getting JPEG content into memory // JPEG to mat Mat imgBuf=Mat(1, jpegContent, CV_8UC3, jpegSize); Mat imgMat=imdecode(imgBuf, CV_LOAD_IMAGE_COLOR); free(jpegContent); if(imgMat.data == NULL) { // Some error handling } // Now the JPEG is decoded and reside in imgMat cvtColor(imgMat, imgMat, CV_BGR2HSV); // Converting to HSV Mat tmp; inRange(imgMat, Scalar(0, 0, 0), Scalar(8, 8, 8),

问题 I want to set the background color of a label using HSV instead of RGB. How do I implement this into code? Code: //.m file #import "IBAppDelegate.h" @implementation IBAppDelegate @synthesize label; { self.label.backgroundColor = [UIColor colorWithRed:1.0f green:0.8f blue:0.0f alpha:1.0f]; } 回答1: You can use the following convenience constructor of the UIColor object: + (UIColor *)colorWithHue:(CGFloat)hue saturation:(CGFloat)saturation brightness:(CGFloat)brightness alpha:(CGFloat)alpha 来源：

问题 I need to change the hue of some pixels of my image, but i don't know how to set them! I converted the image in HSV with CV_BGR2HSV and now i'm cycling with a for by rows and cols... how can I access each pixel's hue? for setting RGB i'm using this code... CvScalar s; s=cvGet2D(imgRGB,i,j); // get the (i,j) pixel value printf("B=%f, G=%f, R=%f\n",s.val[0],s.val[1],s.val[2]); s.val[0]=240; s.val[1]=100; s.val[2]=100; cvSet2D(imgRGB,i,j,s); // set the (i,j) pixel value 回答1: You already

问题 Wikipedia and plethora of online resources provide detailed and abundant help with various color space conversions from/to RGB. What I need is a straight YUV->HSL/HSV conversion . In fact what I need is just the Hue (don't care much for the Saturation or the brightness Lightness/Value). In other words I just need to calculate the "color angle" for a given YUV color. Code in any language would suffice, though my preference is C-style syntax. Note that by YUV I mean specifically Y′UV, a.k.a.

问题 I am a beginner in opencv. I am using opencv v2.1. I have converted an RGB image to HSV image. Now I want to obtain single channels Hue, Value and Saturation separately. What should I do? I have seen similar questions here but No-one answered that. Kindly help. 回答1: You can access the same way you were accessing for RGB image where 1st channel will be for H, 2nd channel for S and 3rd channel for V. If you are using OpenCV 2.1, you must be using IplImage then, right? like if your HSV image is

问题 I am working on a project on detecting traffic signs in opencv. I need a good HSV range to filter out red, blue and yellow traffic signs in the urban environment. This is just so that I have a smaller region of interest. So I do not want a highly accurate range but a rough estimate. Can anyone help me out?? 回答1: You might want to read this link. I extract the interesting part here: How to find HSV values to track? This is a common question found in stackoverflow.com. It is very simple and you