Question

它可能是一个愚蠢的错误，但由于某些原因我的计数器没有递增，对于我的代码底部的所有打印语句，控制台的输出为0。我确保正确读取颜色，这意味着增量代码一定存在问题。

public void countColours(BufferedImage colouredImage) {
        int redCount = 0;
        int greenCount = 0;
        int blueCount = 0;
        int totalPixels = (colouredImage.getWidth()*colouredImage.getHeight());

        for (int x = 0; x < colouredImage.getWidth(); x++) {
            for (int y = 0; y < colouredImage.getHeight(); y++) {

                int red = ((colouredImage.getRGB(x, y)>>> 16) & 0xFF);
                int green = ((colouredImage.getRGB(x, y)>>> 8) & 0xFF);
                int blue = ((colouredImage.getRGB(x, y)) & 0xFF);

                float[] hsb = Color.RGBtoHSB(red, green, blue, null);
                float hue = hsb[0];

                int colour = (int) (hue*360);

                if (colour <= 60 & colour >= 300) {
                    redCount++;
                }

                if (colour >= 60 & colour <= 180) {
                    greenCount++;
                }
                if (colour >= 180 & colour <= 300) {
                    blueCount++;
                }
            }
        }
        int totalRed = (redCount/totalPixels)*100;
        int totalGreen = (greenCount/totalPixels)*100;
        int totalBlue = (blueCount/totalPixels)*100;
        System.out.println(totalRed);
        System.out.println(totalGreen);
        System.out.println(totalBlue);
    }

我已尽可能多地调试，如上所述，颜色是0到360之间的值，但if语句和增量显然不起作用，但我不明白为什么？

提前致谢

Answer 1

你正在混合浮点除法（支持0.75之类的数字）和int除法（将数字舍入为0.75到0）。将您的数字更改为加倍或浮动。

您可以通过添加print语句对此进行测试：

System.out.println("redCount: " + redCount);
System.out.println("totalPixels: " + totalPixels);
System.out.pirntln("redCount/totalPixels: " + (redCount/totalPixels) );

int totalRed = (redCount/totalPixels)*100;

Answer 2

我相信问题不在于你的增量或if语句，而是在这里：

  int totalRed = (redCount/totalPixels)*100;
  int totalGreen = (greenCount/totalPixels)*100;
  int totalBlue = (blueCount/totalPixels)*100;

redCount，greenCount，blueCount和totalPixels都是int，所以当你划分时，结果（应该在1之间）和0）将被截断为零。

要解决这个问题，请在分割之前将你的易行品投射到浮子上：

int totalRed = (int)((float)redCount/totalPixels)*100;
int totalGreen = (int)((float)greenCount/totalPixels)*100;
int totalBlue = (int)((float)blueCount/totalPixels)*100;

在Java中增加错误

2 个答案: