我正在编写一个小型的Java应用程序来分析大量的图像文件。目前,它通过计算图像中每个像素的亮度平均值并将其与文件夹中的其他图像进行比较,以找到文件夹中最亮的图像。
有时,启动后我可以得到100多张图像/秒的速率,但这几乎总会下降到<20张/秒,我不知道为什么。当它达到100+张/秒时,CPU使用率为100%,但接着就降至约20%,这似乎太低了。
以下是主要类:
有时,启动后我可以得到100多张图像/秒的速率,但这几乎总会下降到<20张/秒,我不知道为什么。当它达到100+张/秒时,CPU使用率为100%,但接着就降至约20%,这似乎太低了。
以下是主要类:
public class ImageAnalysis {
public static final ConcurrentLinkedQueue<File> queue = new ConcurrentLinkedQueue<>();
private static final ConcurrentLinkedQueue<ImageResult> results = new ConcurrentLinkedQueue<>();
private static int size;
private static AtomicInteger running = new AtomicInteger();
private static AtomicInteger completed = new AtomicInteger();
private static long lastPrint = 0;
private static int completedAtLastPrint;
public static void main(String[] args){
File rio = new File(IO.CAPTURES_DIRECTORY.getAbsolutePath() + File.separator + "Rio de Janeiro");
String month = "12";
Collections.addAll(queue, rio.listFiles((dir, name) -> {
return (name.substring(0, 2).equals(month));
}));
size = queue.size();
ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() + 1);
for (int i = 0; i < 8; i++){
AnalysisThread t = new AnalysisThread();
t.setPriority(Thread.MAX_PRIORITY);
executor.execute(t);
running.incrementAndGet();
}
}
public synchronized static void finished(){
if (running.decrementAndGet() <= 0){
ImageResult max = new ImageResult(null, 0);
for (ImageResult r : results){
if (r.averageBrightness > max.averageBrightness){
max = r;
}
}
System.out.println("Max Red: " + max.averageBrightness + " File: " + max.file.getAbsolutePath());
}
}
public synchronized static void finishedImage(ImageResult result){
results.add(result);
int c = completed.incrementAndGet();
if (System.currentTimeMillis() - lastPrint > 10000){
System.out.println("Completed: " + c + " / " + size + " = " + ((double) c / (double) size) * 100 + "%");
System.out.println("Rate: " + ((double) c - (double) completedAtLastPrint) / 10D + " images / sec");
completedAtLastPrint = c;
lastPrint = System.currentTimeMillis();
}
}
}
还有线程类:
public class AnalysisThread extends Thread {
@Override
public void run() {
while(!ImageAnalysis.queue.isEmpty()) {
File f = ImageAnalysis.queue.poll();
BufferedImage image;
try {
image = ImageIO.read(f);
double color = 0;
for (int x = 0; x < image.getWidth(); x++) {
for (int y = 0; y < image.getHeight(); y++) {
//Color c = new Color(image.getRGB(x, y));
color += image.getRGB(x,y);
}
}
color /= (image.getWidth() * image.getHeight());
ImageAnalysis.finishedImage((new ImageResult(f, color)));
} catch (IOException e) {
e.printStackTrace();
}
}
ImageAnalysis.finished();
}
}
Thread
,并设置了它的优先级,但是你通过Executor
运行它,而Executor
只将其视为Runnable
,所以这一切都是徒劳的。如果你想影响线程的优先级,你需要定义一个ThreadFactory
。否则,你的类也可以只实现Runnable
。 - user207421ImageIO.setUseCache(false);
吗? - user3707125