void process_image(PNG_Canvas_BW& image) {
int width = image.get_width();
int height = image.get_height();
double kernel[5][5];
double sum = 0;
for (int x=0; x< 5; x++) {
for (int y = 0; y < 5; y++) {
kernel[x][y] = exp((-(x*x)+(y*y))/(2*sigma*sigma));
sum += kernel[x][y];
}
}
/*
for (int x = 0; x<5; x++){
for(int y = 0; y < 5; y++){
printf(" %f ",kernel[x][y]);
}
printf("\n");
}
printf("%f\n",sum);
*/
int K = 2;
double s = 1.0/sum;
//Make a new image canvas for the output to avoid conflicts
PNG_Canvas_BW outputImage(width,height);
for (int y = K; y < height-K-1; y++) {
for (int x = K; x < width-K-1; x++) {
int sum = 0;
for (int j = -K; j <= K; j++) {
for (int i = -K; i <= K; i++) {
int p = image.get_pixel(x+i,y+j);
int c = kernel[j+K][i+K];
sum += c * p;
}
}
int q = round(s*sum);
if (q < 0) q = 0;
if (q > 255) q = 255;
outputImage.set_pixel(x,y,q);
}
}
image = outputImage;
}
void invert_image(PNG_Canvas_BW& image) {
int width = image.get_width();
int height = image.get_height();
//Make a new image canvas for the output to avoid conflicts
PNG_Canvas_BW outputImage(width, height);
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
outputImage[x][y] = 255 - image[x][y];
}
}
//Copy the result back into the provided image
image = outputImage;
}
int main(int argc, char** argv) {
if (argc < 3) {
cerr << "Usage: " << argv[0] << " <input file> <output file>" << endl;
return 0;
}
string input_filename = argv[1];
string output_filename = argv[2];
PNG_Canvas_BW canvas;
if (!canvas.load_image(input_filename)) {
cerr << "Unable to load " << input_filename << ". Exiting..." << endl;
return 0;
}
invert_image(canvas);
canvas.save_image(output_filename);
}
void process_image(PNG_Canvas_BW& image){
int width = image.get_width();
int height = image.get_height();
//image dilatate with and then erode with H
//Make a new image canvas for the output to avoid conflicts
int new_w = width_in;
int new_h = height_in;
PNG_Canvas_BW imagenew(new_w,new_h);
float wnw = ((double) width)/((double)new_w);
float hnh = ((double) height)/((double)new_h);
//printf("%f",wnw);
for (int x = 0; x < new_w; x++){
for (int y = 0; y < new_h; y++){
int x0 = floor(x * wnw);
int y0 = floor(y*hnh);
int x1 = ceil(x*wnw);
int y1 = ceil(y*hnh);
int xs = x - x0;
int ys = y - y0;
int dx = 1 - xs;
int dy = 1 - ys;
int p0 = (image.get_pixel(x0,y0)*dx)+(image.get_pixel(x1,y0)*xs);
int p1 = (image.get_pixel(x0,y1)*dx)+(image.get_pixel(x1,y1)*xs);
int result = (p0 * dy) + (p1 *ys);
if (result > 255) result = 128;
if (result < 0) result = 128;
imagenew.set_pixel(x,y,result);
}
}
//Copy the result back into the provided image
image = imagenew;
}
int main(int argc, char** argv) {
if (argc < 3) {
cerr << "Usage: " << argv[0] << " <input file> <output file>" << endl;
return 0;
}
string input_filename = argv[1];
string output_filename = argv[2];
if (argc == 4) {
sscanf(argv[3],"%lf",&sigma);
}
PNG_Canvas_BW canvas;
if (!canvas.load_image(input_filename)) {
cerr << "Unable to load " << input_filename << ". Exiting..." << endl;
return 0;
}
process_image(canvas);
canvas.save_image(output_filename);
}
void process_image(PNG_Canvas_BW& image){
int width = image.get_width();
int height = image.get_height();
int h[256] = {0};
for (int x =0; x < width; x++){
for (int y = 0; y < height; y++){
h[image.get_pixel(x,y)] = h[image.get_pixel(x,y)]+1;
}
}
int H[256] = {0};
for (int x =0; x < width; x++){
for (int y = 0; y < height; y++){
H[image[x][y]] = H[image[x][y]]+1;
}
}
H[0] = h[0];
for (int a = 1; a < 256; a++){
H[a] = H[a-1] + H[a];
}
//gaussian distribution
double normal[256] = {0};
int sigma = 50;
int m = 128;
float sigmasqr2pi = sigma * sqrt(2*M_PI);
float twosigma2 = 2 * sigma * sigma;
for (int x = 0; x< 256; x++){
normal[x] = exp((-pow((x-m),2))/twosigma2)/(sigmasqr2pi);
}
//inversed bell curve
double gx[256] = {0};
for (int b = 0; b < 256; b ++){
int sigma = 50;
int m = 128;
float sigmasqr2pi = sigma * sqrt(2*M_PI);
float twosigma2 = 2 * sigma * sigma;
float gm = exp((-pow((m-m),2))/twosigma2)/(sigmasqr2pi);
gx[b] = gm - normal[b];
//printf("%f\n",gx[b]);
}
for (int b = 1; b < 256; b++){
gx[b] = gx[b-1]+gx[b];
}
//for (int i = 0; i < 256; i++){
// printf("%f\n",gx[i]);
//}
int F[256] = {0};
int n = width * height;
int r = n/1;
int i = 0;
int c = 0;
int j = 0;
while (i < 256){
if (c <= r*gx[j]){
//printf("%f\n", r*normal[i]);
c += h[i];
F[i] = j;
i = i + 1;
} else {
j = j + 1;
}
}
//Make a new image canvas for the output to avoid conflicts
PNG_Canvas_BW outputImage(width,height);
for (int y = 0; y < height; y++){
for (int x = 0; x < width; x++){
outputImage[x][y] = F[image[x][y]];
}
}
image = outputImage;
}
