处理中带有 Alpha 通道的视频

我想知道是否有人可以出色地帮助我完成我正在做的事情Processing。我需要在实时源上播放带有透明度的视频文件，以便视频不仅仅是一个矩形。这是我认为需要添加或更改的代码部分。我对这一切都非常陌生，我非常感谢任何可以提供帮助的人。

如果您的视频有 Alpha 通道，那就太好了， 否则，你应该能够blend() https://processing.org/reference/PImage_blend_.html其他内容。

这是概念草图的基本证明。它在实时反馈的顶部覆盖了一个圆圈网格。使用空格键循环切换混合模式。有些会比其他效果更好，具体取决于您的内容和您想要实现的目标：

import processing.video.*;

Capture cam;
int w = 320;
int h = 240;
int np = w*h;

PImage overlay;

int blendMode = 1;
int[] blendModes = {BLEND,ADD,SUBTRACT,DARKEST,LIGHTEST,DIFFERENCE,EXCLUSION,MULTIPLY,SCREEN,OVERLAY,HARD_LIGHT,SOFT_LIGHT,DODGE,BURN};
String[] blendModesNames = {"BLEND","ADD","SUBTRACT","DARKEST","LIGHTEST","DIFFERENCE","EXCLUSION","MULTIPLY","SCREEN","OVERLAY","HARD_LIGHT","SOFT_LIGHT","DODGE","BURN"};

void setup(){
  size(w,h);
  cam = new Capture(this,w,h);
  cam.start();

  //test content to overlay, a grid of circles
  background(0);fill(255);
  for(int y = 0 ; y < height; y += 30)
    for(int x = 0 ; x < width; x+= 30)
      ellipse(x,y,15,15);
  overlay = get();
}
void draw(){
  image(cam,0,0);
  blend(overlay,0,0,width,height,0,0,width,height,blendModes[blendMode]);
}
void keyReleased(){
  if(key == ' ') {
    blendMode = (blendMode+1)%blendModes.length;
    println("blendMode: " + blendModesNames[blendMode]);
  }
}
void captureEvent(Capture c){
  c.read();
}