Quantcast
Channel: OpenCV Q&A Forum - RSS feed
Browsing latest articles
Browse All 53 View Live
↧

CamShift on grayscael

Hi, I would like to use Camshift to track the head and retrieve the roll angle like this. Is there a way to use CamShift on a grayscale image? I'm using a Time-of-flight camera and I can only get a...

View Article


TonemapDurand on grayscale images segfaults

I am trying to improve the local contrast of a regular 8-bit gray scale image using tone mapping. I test with the example code...

View Article


Camshift Algorithm and Grayscaled Images

I was wondering whether we could use Camshift with non-HSV images, as every solution on internet simply convert the image into HSV space, single out the H channel and then go further. However, I am...

View Article

16bit raw file stream analysis

Hi, I would like to analyse binary stream data. Data is 16-bit binary stream of 256x256 grayscale images with 256 bytes gaps stored in one long stream file. This is effectively video. Can you give me...

View Article

get few pixels value of grayscale image with android API

Hi men, first of all sorry for my bad englisjh. I need to use a few pixels value of a grayscale image, i've searched everywhere on the web and have understood how read the pixel value but cannot...

View Article


How to convert detected mouth region in gray-scale and binary in android ?

Here is my code, i am not able to covert the mouth region into grayscale please help me...i have tried everything available on internet Mat innerWindow = mRgba.submat(moutharea);...

View Article

Why should an RGB image be converted to grayscale for carrying out...

I am new and naive to OpenCV and image processing. I have an image which is of RGB standard. Why should I convert it grayscale in order to detect blur or apply laplacian operator? Really appreciate...

View Article

Memory error accessing grayscale pixel data

Hi all, Somewhat of a simple question, but haven't found the answer from searching around. I'm trying to work with direct pixel data, and am having trouble figuring out what determines the size of the...

View Article


Normalizing Sobel Filter Noise

I'm writing my own sobel filter and am having trouble getting it to run properly. I'm applying a vertical and horizontal convolution to a grayscale image, which appear to have *some* result when...

View Article


How to capture in GRAYSCALE directly from source

I'm capturing web cam using open cv and I'd like to get direct Grayscale image from source. Below shows a sample code that I'm using for capturing video feed. Found this reference however cant see any...

View Article

convert the RGB image to a grayscale representation of its redness

Hi mate , I need RGB-->Grayscale_redness image that is to convert the more a pixel appears as red in the RGB image, the brighter it will be in the converted image.More specifically, it performs an...

View Article

Accessing Pixel Values of RAW 8 image

Hi all, Im using XIMEA camera and I am capturing RAW 8 images using OpenCV 3.1.0. Therefore my images are in gray scale. Ive read a lot in forums about how to access pixel values. When I use the...

View Article

[SOLVED] putText - result is always black text

Hello, I have a Matrix of type CV_16UC1 which holds 16bit grayscale pixel data from an external camera. I want to use putText to draw WHITE text over the image. But regardless which of the following...

View Article


CV_8UC3 returns grayscale

Excuse me, I'm new to opencv. I learned about CV_8UC3 that it defines an image in 8 bit unsigned integers using 3 channels (BGR). When a color image is loaded using this constant as parameter, cv::Mat...

View Article

Different results between imread as grayscale and cvtColor

Did anyone notice that if you load a color image directly as gray scale, the resulting image is slightly different than loading it to a color image and then cvtColor to grayscale? Anyone know why?...

View Article


Result of CLAHE is different on 8 and 16 bit grayscale image

Hi, I have got a remark, problem with CLAHE algorithm on applying 8 bit and 16 bit grayscale image. I use opencv-master build. So if i applying CLAHE algorithm on 8 bit grayscale image (CV_8UC1), the...

View Article

Better character isolation

Hi, I am trying to process an image, and extract the characters from it. Please see the following link for current work in progress: http://imgur.com/a/FfqwJ At the moment, these are the steps I have...

View Article


How do i convert a Grayscale video to a Tensor?

I have written a code which converts a RGB video to Grayscale and **now I want to convert it to a tensor.** I just gave `cout< #include #include using namespace cv; using namespace std; int...

View Article

ConnectedComponents-like function for grayscale image

I'm looking for help, because I wasn't successful finding a function in OpenCV that is able to perform a labelling of connected components on a grayscale image. **Input:** The input image is an image...

View Article

VideoCapture with grayscale camera

Hello I´m begginer on OpenCv I have a grayscale video camera ELP-USBFHD01M-SFV B/W, 120fps at 480 pixels with picture format MJPEG and YUY2 I need to capture an image almost at 60 FPS. One of my jobs...

View Article

How are RGB images converted to greyscale?

Given 3 images of pure red, pure green, and pure blue, once converted to greyscale I was surprised to find they're not the same shade of grey. I suspect this is the desired behaviour and my initial...

View Article


Is it possible to create a BGR image from predefined 3 (1-channel) image

I am trying to create 1 CV_8UC3 image from 3 different CV_8UC1 images that I already have, i.e I am trying to allocate the different single channel images that I already have into a single 1...

View Article


why load an image with input 0 gives a different result that converting the...

#In Open CV with python, I wrote the following script: import numpy as np import cv2 '''Compare imread( 'detect_blob.png',0) with imread('detect_blob.png',1) and convert to gray scale''' #Method 1 img...

View Article

Open CV Error: Assertion failed (scn ==2 && depth == CV_8U) in cvtColor

Hi all, I'm trying to read a 16-bit float exr image and convert it into grayscale for further image processing using **openCV in python 2.7,** however I encounter the above error "**OpenCV Error:...

View Article

grayscale image pixel-based detect object

I would like to know if opencv allows to detect objects of grayscale image according to their pixel intensities.For example, for the same image, white pixel objects (255), black pixel objects (0) and...

View Article


Failing to read pixel of grayscale image as float

I am trying read\write pixels of a grayscale image as floats but get an exception no matter what I do. Can someone please show me how it's suppose to be done?

View Article

Why at() return 3 values for a grayscale image

Why the grayscale image has 1 channel but still need 'Vec3b' to access the pixel value? And why there should be 3 different values. char* imageName = argv[1]; Mat image; image = imread(imageName, 1);...

View Article

Create 2 channel image - grayscale and alpha

I wish to create a 2-channel png image - 1 channel would be grayscale and 1 channel would be alpha (the bit depth doesn't concern me). I have developed a workaround to achieve this, but this is...

View Article

Metal Edge Defect Detection

Hi, Need help in finding defects in metal(steel or aluminum) edge. Images are in gray scale, with edge in black background. If there is an impression formed by the improper cut of the edge, the images...

View Article



custom grayscale conversion

I'm trying to improve my edge detection and found out, what is logical: some edges are detected better in the red channel, others in the green etc. I would like to use only one Canny-call and not three...

View Article
Browsing latest articles
Browse All 53 View Live