如何在处理中对更多帧的值取平均值

Question

我正在编写此代码来管理和保存来自 Microsoft kinect 的数据，数据存储在 int 数组 int[] depthValues 中，我想做的是存储和保存平均值更多帧（假设为 10），以获得更平滑的数据，将代码的其余部分保持原样。

代码如下：

import java.io.File;
import SimpleOpenNI.*;
import java.util.*;
SimpleOpenNI kinect;
void setup()
{
  size(640, 480);
  kinect = new SimpleOpenNI(this);
  kinect.enableDepth();
}
int precedente = millis();
void draw()
{
  kinect.update();
  PImage depthImage = kinect.depthImage();
  image(depthImage, 0, 0);
  int[] depthValues = kinect.depthMap();

  StringBuilder sb = new StringBuilder();
  Deque<Integer> row = new LinkedList<Integer>();
  int kinectheight = 770; // kinect distance from the baselevel [mm]
  int scaleFactor = 1;
  int pixelsPerRow = 640;
  int pixelsToSkip = 40;
  int rowNum = 0;
  for (int i = 0; i < depthValues.length; i++) {
    if (i > 0 && i == (rowNum + 1) * pixelsPerRow) {
      fillStringBuilder(sb, row);
      rowNum++;
      sb.append("\n");
      row = new LinkedList<Integer>();
    }
    if (i >= (rowNum * pixelsPerRow) + pixelsToSkip) {
      row.addFirst((kinectheight - depthValues[i]) * scaleFactor);
    }
  }
  fillStringBuilder(sb, row);
  String kinectDEM = sb.toString();
  final String[] txt= new String[1]; //creates a string array of 2 elements
  int savingtimestep = 15000;  // time step in millisec between each saving
  if (millis() > precedente + savingtimestep) {
    txt[0] = "ncols         600\nnrows         480\nxllcorner     0\nyllcorner     0\ncellsize      91.6667\nNODATA_value  10\n" +kinectDEM;
    saveStrings("kinectDEM0.tmp", txt);
    precedente = millis();
    //  delete the old .txt file, from kinectDEM1 to kinectDEMtrash
    File f = new File (sketchPath("kinectDEM1.txt"));
    boolean success = f.delete();

    //  rename the old .txt file, from kinectDEM0 to kinectDEM1
    File oldName1 = new File(sketchPath("kinectDEM0.txt"));
    File newName1 = new File(sketchPath("kinectDEM1.txt"));
    oldName1.renameTo(newName1);
    //  rename kinectDEM0.tmp file to kinectDEM0.txt
    File oldName2 = new File(sketchPath("kinectDEM0.tmp"));
    File newName2 = new File(sketchPath("kinectDEM0.txt"));
    oldName2.renameTo(newName2);

  }
}
void fillStringBuilder(StringBuilder sb, Deque<Integer> row) {
  boolean emptyRow = false;
  while (!emptyRow) {
    Integer val = row.pollFirst();
    if (val == null) {
      emptyRow = true;
    } else {
      sb.append(val);
      val = row.peekFirst();
      if (val != null) {
        sb.append(" ");
      }
    }
  }
}

Answer 1

您有一个名为 depthValues 的 int[] 数组变量。您可以像使用任何其他值一样使用此值。换句话说，您可以创建一个包含多个 int[] 值的 array 或 ArrayList。

以下是您可以如何使用 ArrayList 来保存以前的值：

ArrayList<int[]> previousDepthValues = new ArrayList<int[]>();

void draw(){

   //add current depth map to ArrayList
   previousDepthValues.add(kinect.depthMap());

   //limit the ArrayList to hold 10 values
   if(previousDepthValues.size() == 11){
      previousDepthValues.remove(0);
   }

   //create an array to hold the averaged values
   int[] averageDepthValues = new int[previousDepthValues.get(0).length];

   //loop over the 10 previous depth values in the ArrayList
   for(int[] depthValue : previousDepthValues){
      //loop over the ints in each previous depth values array
      for(int i = 0; i < averageDepthValues.length; i++){
         //add all of the values up
         averageDepthValues[i] += depthValue[i];
      }
   }

   //divide each number to get the average
   for(int i = 0; i < averageDepthValues.length; i++){
      averageDepthValues[i] /= averageDepthValues.length;
   }

   //averageDepthValues now holds the average of the last 10 frames

}

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