KeyPressed不同图像视图的卷积问题，例如锐化

Question

以不同的视图显示不同的图像。例如，锐化就是其中之一。我无法让它显示锐化。我不知道如何完成锐化。我以教授的代码为例。还有其他的：blur 3 x 3 blur 5 x 5edge detectiongrayscale RGB > GRBZoom inZoom out我尝试将 1 添加到 for 循环而不是零。这是代码：PImage source;PImage destination;int w = 80;float[][] matrix_3_3_average = {     {1.0/9.0, 1.0/9.0, 1.0/9.0 },     {1.0/9.0, 1.0/9.0, 1.0/9.0 },     {1.0/9.0, 1.0/9.0, 1.0/9.0 }};float[][] matrix_3_3_sharpen =     { { -1, -1, -1 },     { -1, 9, -1 },     { -1, -1, -1 } };void setup() {    size(200, 200);    source = loadImage("sunflower.jpg");              destination = createImage(source.width, source.height, RGB);}void draw() {    destination.loadPixels(); // Tell Processing that we want to read the pixels of the output window    source.loadPixels();     int xStart = constrain(mouseX - w/2, 0, width);    int xEnd = constrain(mouseX + w/2, 0, width);    int yStart = constrain(mouseY - w/2, 0, height);    int yEnd = constrain(mouseY + w/2, 0, height);    if (keyPressed) {        if (key == '0') {            image(source, 0, 0);            for (int x = 1; x < source.width; x++) {                for (int y = 1; y < source.height; y++) {                    int loc = x + y * source.width;                    if ((x > xStart) && (x < xEnd) && (y > yStart) && (y < yEnd))                         destination.pixels[loc] = convolution(x, y, matrix_3_3_average, 3, source);                    else                         // set the color of the corresponding pixel to the output window to the color of the pixel to the input image                        destination.pixels[loc] = source.pixels[loc];                }            }        } 

Answer 1

在函数中计算图像计划中像素的索引时存在问题convolution。一个像素的索引是 x + y * width而不是x * width：

int loc = xLoc * yLoc * img.width;</s>

int loc = xLoc + yLoc * img.width;

将source图像复制到destination启动时并不断绘制destination 图像：

void setup() {

    size(200, 200);

    source = loadImage("C:/temp/flower.jpg"); //source = loadImage("sunflower.jpg"); 

    destination = createImage(source.width, source.height, RGB);

    destination.copy(source, 0, 0, source.width, source.height, 0, 0, source.width, source.height);

}

void draw() {

    // [...]

    image(destination, 0, 0);

}  

使用 keyPressed()事件来识别是否key按下了 a，这将启动图像过滤器：

boolean average = key == '0';

boolean sharpen = key == '1';

void keyPressed() {

    average = key == '0';

    sharpen = key == '1';

}

当执行图像过滤器时，将图像复制source到destination图像中。更新过滤区域中的像素。最后将更改后destination的图像复制到源图像，为下一次过滤操作做准备：

destination.copy(source, 0, 0, source.width, source.height, 0, 0, source.width, source.height);

for (int x = 0; x < source.width; x++) {

    for (int y = 0; y < source.height; y++) {

        int loc = x + y * source.width;

        if (x > xStart && x < xEnd && y > yStart && y < yEnd) {

            if ( average )

                destination.pixels[loc] = convolution(x, y, matrix_3_3_average, 3, source);

            else

                destination.pixels[loc] = convolution(x, y, matrix_3_3_sharpen, 3, source);

        }

    }

}

source.copy(destination, 0, 0, source.width, source.height, 0, 0, source.width, source.height);

请参阅示例，其中我将建议应用于您的问题代码：

PImage source;

PImage destination;

int w = 80;

float[][] matrix_3_3_average = { 

    {1.0/9.0, 1.0/9.0, 1.0/9.0 }, 

    {1.0/9.0, 1.0/9.0, 1.0/9.0 }, 

    {1.0/9.0, 1.0/9.0, 1.0/9.0 }

};

float[][] matrix_3_3_sharpen = 

    { { -1, -1, -1 }, 

    { -1, 9, -1 }, 

    { -1, -1, -1 } };

void setup() {

    size(200, 200);

    source = loadImage("C:/temp/flower.jpg"); //source = loadImage("sunflower.jpg"); 

    destination = createImage(source.width, source.height, RGB);

    destination.copy(source, 0, 0, source.width, source.height, 0, 0, source.width, source.height);

}

boolean average = key == '0';

boolean sharpen = key == '1'; 

void keyPressed() {

    average = key == '0';

    sharpen = key == '1'; 

}

void draw() {

    int xStart = constrain(mouseX - w/2, 0, width);

    int xEnd = constrain(mouseX + w/2, 0, width);

    int yStart = constrain(mouseY - w/2, 0, height);

    int yEnd = constrain(mouseY + w/2, 0, height);

    println(xStart, xEnd, yStart, yEnd);

    if (average || sharpen) { 

        destination.copy(source, 0, 0, source.width, source.height, 0, 0, source.width, source.height);

        for (int x = 0; x < source.width; x++) {

            for (int y = 0; y < source.height; y++) {

                int loc = x + y * source.width;

                if (x > xStart && x < xEnd && y > yStart && y < yEnd) {

                    if ( average )

                        destination.pixels[loc] = convolution(x, y, matrix_3_3_average, 3, source);

                    else

                        destination.pixels[loc] = convolution(x, y, matrix_3_3_sharpen, 3, source);

                }                   

            }

        }

        source.copy(destination, 0, 0, source.width, source.height, 0, 0, source.width, source.height);

        average = sharpen = false; 

    }

    image(destination, 0, 0);

}  

color convolution(int x, int y, float[][] matrix, int matrixSize, PImage img) {

    int offset = (matrixSize - 1)/2;

    float r = 0;

    float g = 0;

    float b = 0;

    for (int i = 0; i < matrixSize; i++) {  

        for (int j = 0; j < matrixSize; j++) {

            int xLoc = x + i - offset;

            int yLoc = y + j - offset;

            int loc = xLoc + yLoc * img.width;

            loc = constrain(loc, 0, img.pixels.length-1);

            r = r + matrix[i][j] * red(img.pixels[loc]);

            g = g + matrix[i][j] * green(img.pixels[loc]);

            b = b + matrix[i][j] * blue(img.pixels[loc]);

        }

    }

    return color(r, g, b);

}