Question

民间，

我有一个真实的SR300，但是当我在opencv窗口中显示我的深度图像时，它看起来太暗了。我怎样才能解决这个问题？当我运行realsense示例时，图像看起来很好，但示例使用OpenGL。但是我的项目需要OpenCV。这是我的代码：

int main(int argc, char ** argv)
{
  // realsense camera setup
  rs::log_to_console(rs::log_severity::warn);
  // Create a context object. This object owns the handles to all connected realsense devices
  rs::context ctx;
  if (ctx.get_device_count() == 0)
  {
    throw std::runtime_error("No device detected. Is it plugged in?");
  }
  // Access the first available RealSense device
  rs::device * dev = ctx.get_device(0);
  // Configure depth to run at VGA resolution at 30 frames per second
  dev->enable_stream(rs::stream::depth, 640, 480, rs::format::z16, 30);
  rs::intrinsics depth_intrin;
  rs::format depth_format;
  depth_intrin = dev->get_stream_intrinsics(rs::stream::depth);
  depth_format = dev->get_stream_format(rs::stream::depth);
  cv::namedWindow("Send Display Image", CV_WINDOW_AUTOSIZE);

  /* Set callbacks prior to calling start(). */
  auto depth_callback = [depth_intrin, depth_format](rs::frame f)
  {
    cv::Mat image(cv::Size(640, 480), CV_16UC1,
      (void*)f.get_data(), cv::Mat::AUTO_STEP);
    cv::imshow("Send Display Image", image);
    cv::waitKey(1000/80);
  };
  /* callback to grab depth fream and publish it. */
  dev->set_frame_callback(rs::stream::depth, depth_callback);
  // Start streaming
  dev->start();
  While(1)
  {

  }
  return 0;
}

我不确定为什么我的图像太暗了。当我从ROS运行openni_launch时，我希望它看起来像kinect或Xtion

Answer 1

修改

下面的规范化函数会产生一些闪烁：

我怀疑这是由于最大深度值闪烁造成的。

最小深度值始终为0，因为当深度无效时使用此值，因此深度范围变为false。

相反，你应该使用它：

void make_depth_histogram(const Mat &depth, Mat &normalized_depth) { normalized_depth = Mat(depth.size(), CV_8U); int width = depth.cols, height = depth.rows; static uint32_t histogram[0x10000]; memset(histogram, 0, sizeof(histogram)); for(int i = 0; i < height; ++i) { for (int j = 0; j < width; ++j) { ++histogram[depth.at<ushort>(i,j)]; } } for(int i = 2; i < 0x10000; ++i) histogram[i] += histogram[i-1]; // Build a cumulative histogram for the indices in [1,0xFFFF] for(int i = 0; i < height; ++i) { for (int j = 0; j < width; ++j) { if (uint16_t d = depth.at<ushort>(i,j)) { int f = histogram[d] * 255 / histogram[0xFFFF]; // 0-255 based on histogram location normalized_depth.at<uchar>(i,j) = static_cast<uchar>(f); } else { normalized_depth.at<uchar>(i,j) = 0; } } } }

您观察到的是深度流以16位（rs::stream::z16）编码，而显示时仅使用8位。

您可以规范化深度图：

double min, max; minMaxLoc(depth, &min, &max); Mat depth_normalized; double alpha = 255.0/(max-min); depth.convertTo(depth_normalized, CV_8U, alpha, -min*alpha);

或使用一种色彩图来显示深度：make_depth_histogram()。

完整的演示代码：

inline void make_depth_histogram(const Mat &depth, Mat &color_depth) { color_depth = Mat(depth.size(), CV_8UC3); int width = depth.cols, height = depth.rows; static uint32_t histogram[0x10000]; memset(histogram, 0, sizeof(histogram)); for(int i = 0; i < height; ++i) { for (int j = 0; j < width; ++j) { ++histogram[depth.at<ushort>(i,j)]; } } for(int i = 2; i < 0x10000; ++i) histogram[i] += histogram[i-1]; // Build a cumulative histogram for the indices in [1,0xFFFF] for(int i = 0; i < height; ++i) { for (int j = 0; j < width; ++j) { if (uint16_t d = depth.at<ushort>(i,j)) { int f = histogram[d] * 255 / histogram[0xFFFF]; // 0-255 based on histogram location color_depth.at<Vec3b>(i,j) = Vec3b(f, 0, 255 - f); } else { color_depth.at<Vec3b>(i,j) = Vec3b(0, 5, 20); } } } } int main(int argc, char *argv[]) { // Create a context object. This object owns the handles to all connected realsense devices rs::context ctx; // Access the first available RealSense device rs::device * dev = ctx.get_device(0); // Configure Infrared stream to run at VGA resolution at 30 frames per second dev->enable_stream(rs::stream::depth, 640, 480, rs::format::z16, 30); // Start streaming dev->start(); // Camera warmup - Dropped several first frames to let auto-exposure stabilize for(int i = 0; i < 30; i++) dev->wait_for_frames(); // Creating OpenCV Matrix from a color image Mat depth(Size(640, 480), CV_16U, (void*)dev->get_frame_data(rs::stream::depth), Mat::AUTO_STEP); // Create a color depth Mat color_depth; make_depth_histogram(depth, color_depth); // Create a normalized depth double min, max; minMaxLoc(depth, &min, &max); Mat depth_normalized; double alpha = 255.0/(max-min); depth.convertTo(depth_normalized, CV_8U, alpha, -min*alpha); // Display in a GUI imshow("Display normalized depth", depth_normalized); imshow("Display color depth", color_depth); waitKey(0); return 0; }

Answer 2

我发现这个问题的唯一解决方案是：

将图像另存为PNG文件。（PNG支持保存16位图像）

使用matplotlib在彩色地图中查看。

#!/usr/bin/python3
import numpy as np
import cv2
import sys
from matplotlib import pyplot as plt

def printCoordinates(event):
    x,y = event.xdata,event.ydata
    if x != None:
        print("X : ",x," Y: ",y," Value = ",img[np.int(y),np.int(x)])

img = cv2.imread(sys.argv[1],cv2.CV_16UC1)
#img = img/65535

fig = plt.figure()
plt.imshow(img,cmap='nipy_spectral')
cid = fig.canvas.mpl_connect('button_press_event',printCoordinates)
plt.colorbar()
plt.show()

button_press_event用于在点击的像素上打印精确的像素值。

RGB图像相应的深度图像

RealSense OpenCV深度图像太暗

2 个答案: