void idct_8x8(double **input, gray **output) {
double temp[ NJPEG ][ NJPEG ];
double temp1;
int i;
int j;
int k;
/* MatrixMultiply( temp, input, C ); */
for ( i = 0 ; i < NJPEG ; i++ ) {
for ( j = 0 ; j < NJPEG ; j++ ) {
temp[ i ][ j ] = 0.0;
for ( k = 0 ; k < NJPEG ; k++ )
temp[ i ][ j ] += input[ i ][ k ] * C[ k ][ j ];
}
}
/* MatrixMultiply( output, Ct, temp ); */
for ( i = 0 ; i < NJPEG ; i++ ) {
for ( j = 0 ; j < NJPEG ; j++ ) {
temp1 = 0.0;
for ( k = 0 ; k < NJPEG ; k++ )
temp1 += Ct[ i ][ k ] * temp[ k ][ j ];
temp1 += 128.0;
output[i][j] = PIXELRANGE(ROUND(temp1));
}
}
}
void idct_NxM(double **dcts, gray **pixels) {
int x, y;
int i, j;
double cx0 = sqrt(1.0 / N);
double cy0 = sqrt(1.0 / M);
double t;
for (x = 0; x < N; x++) {
for (y = 0; y < M; y++) {
t = cx0 * cy0 * dcts[0][0];
for (i = 1; i < N; i++)
t += cy0 * dcts[0][i] * dct_NxM_costable_x[x][i];
for (j = 1; j < M; j++)
t += cx0 * dcts[j][0] * dct_NxM_costable_y[y][j];
for (i = 1; i < N; i++) {
double s = 0.0;
for (j = 1; j < M; j++) {
s += dcts[j][i] * dct_NxM_costable_y[y][j];
}
t += s * dct_NxM_costable_x[x][i];
}
pixels[y][x] = PIXELRANGE((int) (t + 128.5));
}
}
}
void idct_NxN(double **dcts, gray **pixels) {
int u,v;
double two_over_sqrtncolsnrows = 2.0/sqrt((double) N*M);
double **tmp;
tmp = alloc_coeffs(N, N);
for (u=0;u<N;u++)
for (v=0;v<M;v++)
tmp[u][v] = dcts[u][v];
for (u=0; u<=M-1; u++){
ifct_noscale(tmp[u]);
}
for (v=0; v<=N-1; v++){
for (u=0; u<=M-1; u++){
dct_NxN_tmp[u] = tmp[u][v];
}
ifct_noscale(dct_NxN_tmp);
for (u=0; u<=M-1; u++){
tmp[u][v] = dct_NxN_tmp[u]*two_over_sqrtncolsnrows;
}
}
for (u=0;u<N;u++)
for (v=0;v<M;v++)
pixels[u][v] = PIXELRANGE(tmp[u][v] + 128.5);
free(tmp);
}
void image_to_gray(Image img_scaled, gray *pixels) {
//image must be scaled by get_absolute_image_scaled()
int i, j;
for (i = 0; i < img_scaled->height; i++)
for (j = 0; j < img_scaled->width; j++)
pixels[j + (i*(img_scaled->width))] = PIXELRANGE((int)(get_pixel(img_scaled, j, i) + 0.5));
}
void idwt_wp(Image_tree dwts, gray **pixels) {
Image image;
int i, j;
image = inv_transform(dwts, dwt_filters, dwt_method + 1);
for (i = 0; i < dwt_rows; i++)
for (j = 0; j < dwt_cols; j++)
pixels[i][j] = PIXELRANGE((int) (get_pixel(image, j, i) + 0.5));
printf("idwt_wp(): working!!\n");
free_image(image);
}
void idwt(Image_tree dwts, gray *pixels) {
Image image;
int i, j;
image = inv_transform(dwts, dwt_filters, dwt_method + 1);
for (i = 0; i < dwt_rows; i++)
for (j = 0; j < dwt_cols; j++)
// pixels[i][j] = PIXELRANGE((int) (get_pixel(image, j, i) + 0.5));
pixels[j + (i*(image->width))] = PIXELRANGE((int) (get_pixel(image, j, i) + 0.5));
// for (i = 0; i < (dwt_cols*dwt_rows); i++) pixels[i] = PIXELRANGE((int)(image->data[i] + 0.5));
free_image(image);
free_image_tree(dwts);
}
