图像数字图像处理Java直方图不工作

Question

我试图得到一些不同的直方图，以显示比较原始图像和卷积后的输出图像。它显示了图像和源直方图，但当我调用dst直方图时，它会出错并且不显示。如果有人能帮忙，我们将不胜感激

错误代码-

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 853
    at iptoolkit.Histogram.<init>(Histogram.java:15)
    at assignment2.main(assignment2.java:82)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)

Process finished with exit code 0

代码-

    public static void main(String[] args) throws Exception 
    {

        MainWindow mw = new MainWindow();
        mw.println("Testing...");

        IntImage src = new IntImage("C:\\Users\\scott_000\\Documents\\Digital Imaging\\Digital Imaging\\Images\\Baboon.bmp"); //destination for source image
        int nRows = src.getRows(); //calculating the rows of the images and columns
        int nCols = src.getCols();
        IntImage dst = new IntImage(nRows, nCols); //setting destination image(output image)
        IntImage dst1 = new IntImage(nRows, nCols);


        src.displayImage(400, 300); //displaying the source image (input)

        int [][] mask = new int[][] { {-1, -2, -1}, {0, 0, 0}, {1, 2, 1} }; //mask imput (sobel masks in order from top to bottom

        int [][] meanMask = new int[3][3];
        meanMask[0][0] = 1;
        meanMask[0][1] = 1;
        meanMask[0][2] = 1;
        meanMask[1][0] = 1;   // 1 1 1
        meanMask[1][1] = 1;   // 1 1 1
        meanMask[1][2] = 1;   // 1 1 1
        meanMask[2][0] = 1;
        meanMask[2][1] = 1;
        meanMask[2][2] = 1;

        int [][] mask5x5 = new int[5][5];
        mask5x5[0][0] = 1;
        mask5x5[0][1] = 1;
        mask5x5[0][2] = 1;
        mask5x5[0][3] = 1;
        mask5x5[0][4] = 1;
        mask5x5[1][0] = 1;
        mask5x5[1][1] = 1;
        mask5x5[1][2] = 1;
        mask5x5[1][3] = 1;
        mask5x5[1][4] = 1;
        mask5x5[2][0] = 1;
        mask5x5[2][1] = 1;
        mask5x5[2][2] = 1;   // 1 1 1 1 1
        mask5x5[2][3] = 1;   // 1 1 1 1 1
        mask5x5[2][4] = 1;   // 1 1 1 1 1
        mask5x5[3][0] = 1;
        mask5x5[3][1] = 1;
        mask5x5[3][2] = 1;
        mask5x5[3][3] = 1;
        mask5x5[3][4] = 1;
        mask5x5[4][0] = 1;
        mask5x5[4][1] = 1;
        mask5x5[4][2] = 1;
        mask5x5[4][3] = 1;
        mask5x5[4][4] = 1;


        convolve(src, mask5x5, dst); //calling convolve method, with input image(src), template(mask) and output image(dst)
        dst.setScaling(true); //scales the image down to 255
        dst.displayImage(); //display the output image

        convolve(src, meanMask, dst1); //calling convolve method, with input image(src), template(mask) and output image(dst)
        dst1.setScaling(true); //scales the image down to 255
        dst1.displayImage(); //display the output image

        Histogram h = new Histogram(src);
        IntImage histImage;
        histImage = h.makeImage(); //setting and displaying histogram
        histImage.displayImage();

        Histogram y = new Histogram(dst1);
        IntImage histImage1;
        histImage1 = y.makeImage(); //setting and displaying histogram
        histImage1.displayImage();





    }


    static IntImage convolve(IntImage in, int[][] template, IntImage out) //parameters to be set
    {
        int nRows = in.getRows(); //find out how many of rows there are and cols
        int nCols = in.getCols();

        int nMaskRows = template.length; //set length of rows and cols
        int nMaskCols = template[0].length;
        int rBoarder = nMaskRows / 2; //calculation for the border of the image
        int cBoarder = nMaskCols / 2;
        int sum; //used for the calculation

        for (int r = 0; r < (nRows - nMaskRows + 1); r++) //start at the first row(top left) and work to the right, number of rows - mask rows(whatever the mask is)
        {
            for (int c = 0; c < (nCols - nMaskCols + 1); c++) //same as above
            {
                sum = 0; //declaring the sum as 0
                for (int mr = 0; mr < nMaskRows; mr++)
                {
                    for (int mc = 0; mc < nMaskCols; mc++)
                    {
                        sum += in.pixels[r + mr][c + mc] * template[mr][mc]; //change this for calculating the edge preserving smoothing (mean, median etc)
                    }
                }
                out.pixels[r + rBoarder][c + cBoarder] = sum;
            }
        }

        return out;
    }

}

Answer 1

你的ArrayIndexOutOfBoundsException可能是因为你的Sobel过滤器可以输出负值。很可能你的直方图没有预料到这一点

我找不到有关您正在使用的库的任何信息（iptoolkit？）但我会阅读直方图文档，看看它是否提供了关于如何处理负值的任何线索

Answer 2

必须缩小图像，使用这种方法。谢谢你的帮助威士忌皮德

static IntImage scale(IntImage in, int newMin, int newMax) {
    int oldMin, oldMax;
    double scaleFactor;
    int nRows = in.getRows();
    int nCols = in.getCols();
    IntImage out = new IntImage(nRows, nCols);

    oldMin = oldMax = in.pixels[0][0];
    for (int r = 0; r < nRows; r++)
    {
        for (int c = 0; c < nCols; c++)
        {
            if (in.pixels[r][c] < oldMin)
            {
                oldMin = in.pixels[r][c];
            } else {
                if (in.pixels[r][c] > oldMax)
                {
                    oldMax = in.pixels[r][c];


                }
            }
        }

    }

//计算比例因子

    scaleFactor = (double) (newMax - newMin) / (double) (oldMax - oldMin);
    for (int r = 0; r < nRows; r++)
    {
        for (int c = 0; c < nCols; c++)
        {
            out.pixels[r][c] = (int) Math.round(newMin +
                    (in.pixels[r][c] - oldMin) * scaleFactor);


        }


    } //scale

    return out;

}