java - 需要使用矩阵平滑图像 - 计算单元格总和并计算平均值

Question

我有矩阵，每个单元格包含我需要计算该单元格及其相邻单元格的数字，并得出该单元格的平均值。

看看我写的代码。

public Matrix imageFilterAverage() {
        for (int i=0; i < _array.length;i++)
            for (int j=0; i < _array[i].length;j++){
                _array[i][j] = (_array[i][j] + _array[i][j+1] + _array[i+1][j] + _array[i+1][j+1]) / 4;
            }

        return this;
    }

当 j+1 达到 3 时，我的代码在索引问题上返回错误，它超出范围，因为单元格为 0 1 2。

例如，如果我有一个像这样的矩阵

10 5 7 3
50 3 2 1
60 2 5 2

结果矩阵应该是这样的。

17 12 3 3
21 16 2 3
28 20 2 2

我已经发布了图像一个矩阵源和矩阵结果

非常感谢您的时间和帮助。

Answer 1

    /**
         * Takes the given array and transforms each slot in the array as an average of the slots around it.
         * @return an array with each where each slot in the array is "blurred" by the slots around it.
         */
        public Matrix imageFilterAverage() {
            int avgArray[][] = new int[_twoDiPicture.length][];
            int numOfCellsAround = 0;
            int cellsSum = 0;
            for (int y = 0; y < _twoDiPicture.length; y++) {
                avgArray[y] = new int[_twoDiPicture[y].length];
                for (int x = 0; x < _twoDiPicture[y].length; x++) {
                    numOfCellsAround = 0;
                    cellsSum = 0;
                    numOfCellsAround += cellsAround(y, x);
                    cellsSum += cellsSum(y, x);
                    avgArray[y][x] = cellsSum / numOfCellsAround;
                }
            }

            return new Matrix(avgArray);
        }

/* a private method that  deals with index out of bound exceptions. */
    private boolean isInBounds(int y, int x) {
        return y < _twoDiPicture.length && y >= 0 && x < _twoDiPicture[y].length  && x >= 0;
    }

    /* A private methods that uses "isInBounds" to find how many cells are surrounding the target array. */
    private int cellsAround(int y, int x) {
        int cells = 1;

        if (isInBounds(y + 1, x)) {
            cells++;
        }
        if (isInBounds(y - 1, x)) {
            cells++;
        }
        if (isInBounds(y, x + 1)) {
            cells++;
        }
        if (isInBounds(y, x - 1)) {
            cells++;
        }
        if (isInBounds(y - 1, x + 1)) {
            cells++;
        }
        if (isInBounds(y - 1, x - 1)) {
            cells++;
        }
        if (isInBounds(y + 1, x - 1)) {
            cells++;
        }
        if (isInBounds(y + 1, x + 1)) {
            cells++;
        }

        return cells;
    }


    /*A private method that returns the sum of all the adjacent cells around target cell. */
    private int cellsSum(int y, int x) {
        int sum = _twoDiPicture[y][x];

        if (isInBounds(y + 1, x)) {
            sum += _twoDiPicture[y + 1][x];
        }
        if (isInBounds(y - 1, x)) {
            sum += _twoDiPicture[y - 1][x];
        }
        if (isInBounds(y, x + 1)) {
            sum += _twoDiPicture[y][x + 1];
        }
        if (isInBounds(y, x - 1)) {
            sum += _twoDiPicture[y][x - 1];
        }
        if (isInBounds(y - 1, x + 1)) {
            sum += _twoDiPicture[y - 1][x + 1];
        }
        if (isInBounds(y - 1, x - 1)) {
            sum += _twoDiPicture[y - 1][x - 1];
        }
        if (isInBounds(y + 1, x - 1)) {
            sum += _twoDiPicture[y + 1][x - 1];
        }
        if (isInBounds(y + 1, x + 1)) {
            sum += _twoDiPicture[y + 1][x + 1];
        }

        return sum;
    }