Cycle through pixels with opencv

How would I be able to cycle through an image using opencv as if it were a 2d array to get the rgb values of each pixel? Also, would a mat be preferable over an iplimage for this operation? 如果您使用C ++,请使用opencv的C ++接口,然后您可以通过http://docs.opencv.org/2.4/doc/tutorials/core/how_to_scan_images/how_to_scan_images.html#the-efficient-way访问成员或使用例如,cv :: Mat :: at()。 cv::

使用opencv循环显示像素

我如何能够使用opencv循环访问一个图像,就好像它是一个二维数组,以获得每个像素的rgb值? 另外,对于这个操作,在iplimage上最好使用垫子吗? 如果您使用C ++,请使用opencv的C ++接口,然后您可以通过http://docs.opencv.org/2.4/doc/tutorials/core/how_to_scan_images/how_to_scan_images.html#the-efficient-way访问成员或使用例如,cv :: Mat :: at()。 cv::Mat优于IplImage因为它简化了你的代码 cv::Mat img = cv::

Compare intensity pixel value Vec3b in OpenCV

I have a 3 channel Mat image, type is CV_8UC3 . I want to compare, in a loop, the intensity value of a pixel with its neighbours and then set 0 or 1 if the neighbour is greater or not. I can get the intensity calling Img.at<Vec3b>(x,y) . But my question is: how can I compare two Vec3b ? Should I compare pixels value for every channel (BGR or Vec3b[0] , Vec3b[1] and Vec3b[2] ), and the

比较OpenCV中的强度像素值Vec3b

我有一个3通道Mat图片,类型是CV_8UC3 。 我想在一个循环中比较一个像素与它的邻居的强度值,然后如果邻居较大或不相邻,则设置为0或1 。 我可以调用Img.at<Vec3b>(x,y) 。 但我的问题是:我如何比较两个Vec3b ? 我应该比较每个通道(BGR或Vec3b[0] , Vec3b[1]和Vec3b[2] )的像素值,然后将三个通道结果合并为一个Mat对象? 又是我 :) 如果您想比较(大于或小于)两个RGB值,则需要将三维RGB空间投影到平面

How to understand the average pixel number described in the frequency image?

I'm trying to implement the widely used fingerprint image enhancement algorithm proposed by Anil Jain et al. While implementing the steps for ridge frequency image calculation in Section 2.5, I have difficulties in understanding some description. The steps are described as follows: Obtain normalized image G. Divide G into blocks of size wxw (16 x 16). For each block centered at the pi

如何理解频率图像中描述的平均像素数?

我试图实现由Anil Jain等人提出的广泛使用的指纹图像增强算法。 在第2.5节中实施脊波频率图像计算的步骤时,我很难理解某些描述。 步骤描述如下: 获得归一化图像G. 将G分成大小为wxw(16 x 16)的块。 对于以像素(i,j)为中心的每个块,计算在脊坐标系中定义的大小为lxw(32x16)的定向窗口。 对于以像素(i,j)为中心的每个块,计算定向窗口内的脊和谷的x签名X [0],X1,...,X [l-1],其中 如果在定向窗口中没

Obtaining list of unique pixel values in OpenCV Mat

Is there an equivalent of np.unique() or bincount() for an OpenCV Mat ? I am working with C++ so can't just convert to a numpy array. No, there is not! You can code your own, though: std::vector<float> unique(const cv::Mat& input, bool sort = false) Find the unique elements of a single channel cv::Mat. Parameters: input: It will be treated as if it was 1-D. sort: Sorts t

获取OpenCV Mat中唯一的像素值列表

OpenCV Mat有相当于np.unique()或bincount()吗? 我正在使用C ++,所以不能只是转换为numpy数组。 不,那里没有! 不过,您可以编写自己的代码: std::vector<float> unique(const cv::Mat& input, bool sort = false) 找到单个频道cv :: Mat的独特元素。 参数: 输入:它将被视为是1-D。 排序:对唯一值进行排序(可选)。 这种功能的实现非常简单,但是,以下仅适用于单通道 CV_32F : #include <a

Get frame from video with libvlc smem and convert it to opencv Mat. (c++)

[UPDATED WITH PARTIAL ANSWER] Here is my code: void cbVideoPrerender(void *p_video_data, uint8_t **pp_pixel_buffer, int size) { // Locking imageMutex.lock(); videoBuffer = (uint8_t *)malloc(size); *pp_pixel_buffer = videoBuffer; } void cbVideoPostrender(void *p_video_data, uint8_t *p_pixel_buffer , int width, int height, int pixel_pitch, int size, int64_t pts) { // U

使用libvlc smem从视频获取帧并将其转换为opencv Mat。 (C ++)

[更新部分答案] 这是我的代码: void cbVideoPrerender(void *p_video_data, uint8_t **pp_pixel_buffer, int size) { // Locking imageMutex.lock(); videoBuffer = (uint8_t *)malloc(size); *pp_pixel_buffer = videoBuffer; } void cbVideoPostrender(void *p_video_data, uint8_t *p_pixel_buffer , int width, int height, int pixel_pitch, int size, int64_t pts) { // Unlocking image

stop an infinite loop

I have been trying to trace the contour (line) of a surface in an 2D grayscale image using OpenCV and C++, but, I keep running into an infinite loop. I've tried all sorts of debugging, and cannot rectify my problem. Please help! My image looks like this: http://snag.gy/fAs9a.jpg (fourth image) This is what my "initial" contour looks like: http://snag.gy/fAs9a.jpg (fifth image)

停止无限循环

我一直试图使用OpenCV和C ++在二维灰度图像中追踪曲面的轮廓(线条),但是我一直运行到无限循环。 我尝试了各种调试,但无法纠正我的问题。 请帮忙! 我的图像如下所示:http://snag.gy/fAs9a.jpg(第四张图片) 这是我的“初始”轮廓看起来像:http://snag.gy/fAs9a.jpg(第五图像) 这是我迄今为止所做的: 初始化包含图像中表面“初始”轮廓的图像蒙版。 在掩码中,获取所有值大于255的点坐标,并将它们存储在向量中

shrink objects to pixels

I am processing such an image as shown in Fig.1, which is composed of an array of points and required to convert to Fig. 2. Fig.1 original image Fig.2 wanted image In order to finish the conversion, firstly I detect the edge of every point and then operate dilation . The result is satisfactory after choosing the proper parameters, seen in Fig. 3. Fig.3 image after dilation I processed

将对象缩小到像素

我正在处理如图1所示的图像,该图像由点阵组成,并且需要转换为图2。 图1原始图像 图2想要的图像 为了完成转换,首先检测每个点的edge ,然后进行dilation 。 选择合适的参数后,结果令人满意,如图3所示。 图3扩张后的图像 我在MATLAB中处理过相同的图像。 当将物体(如图3)缩小到像素时,函数bwmorph(Img,'shrink',Inf)起作用,其结果恰好来自图2所示的位置。 那么如何在opencv中获得相同的想要的图像?

OpenCV Error Assertion failed on some Pixal Values

I loaded an Image to a Mat: Mat Mask = cvLoadImage(filename); Its an 3744 X 5616 RGB Image. On the next Step i convert it to an Grayscale. cvtColor(Mask,Mask,CV_BGR2GRAY); after this i normalize it to use the full Grayscale later: normalize(Mask,Mask,0,255,NORM_MINMAX,CV_8U); Now i need the specific Grayscale values and getting an Error on some Values: for(int i=0;i<(Picture.rows);i++)

OpenCV错误声明在某些Pixal值上失败

我将一张图片加载到垫子上: Mat Mask = cvLoadImage(filename); 它是一个3744 X 5616 RGB图像。 在下一步我将其转换为灰度。 cvtColor(Mask,Mask,CV_BGR2GRAY); 在此之后,我将其规格化为稍后使用完整的灰度: normalize(Mask,Mask,0,255,NORM_MINMAX,CV_8U); 现在我需要特定的灰度值并获取某些值的错误: for(int i=0;i<(Picture.rows);i++) { for(int j=0;j<(Picture.cols);j++) { Vec3b masked = Mask

normalize histogram in c++

I need to normalize the histogram of an image f which mean to applicated an transformation of histogram from image in order to extend the range of value of f to all available values. the norm(fmin) = Vmin ( minimal value we want to reach) and normal(fmin) = Vmax ( maximal value we want to reach) I have this formula too the goal is to have the same result that the function normalize which ope

在c ++中规格化直方图

我需要对图像f的直方图进行归一化处理,这意味着应用图像中直方图的变换,以便将f值的范围扩展到所有可用值。 范数(fmin)= Vmin(我们想要达到的最小值)和正常(fmin)= Vmax(我们想要达到的最大值) 我也有这个公式 目标是具有相同的结果,该函数可以规范openCV给出的结果。 Mat normalize(Mat image, float minValue, float maxValue) { Mat res = image.clone(); assert(minValue <= maxValue); float Fmax

Normalising an image in opencv

I have a RGB image stored in a Mat datastructure. I am converting the image into grayscale using cvtColor function in opencv. After that I am trying to normalise the image to the range [0,1]. I am using the default normalize function of opencv. To check the correctness, I tried printing the pixel values and equate it with matlab values(Matlab values are already in the range [0,1]). But the v

在opencv中规范图像

我有一个存储在Mat数据结构中的RGB图像。 我正在使用opencv中的cvtColor函数将图像转换为灰度。 之后,我试图将图像标准化到范围[0,1]。 我正在使用opencv的默认标准化函数。 为了检查正确性,我尝试打印像素值并将其与matlab值相等(Matlab值已经在[0,1]范围内)。 但是这些数值差异很大。 帮助我使两个结果几乎相同。 以下是opencv和matlab代码。 Mat img1 = imread("D:/input.png", CV_LOAD_IMAGE_COLOR); cvtColor(im