/**
* Function: gdImageCropThreshold
*
* Crop an image using a given color
*
* The _threshold_ defines the tolerance to be used while comparing the image
* color and the color to crop. The method used to calculate the color
* difference is based on the color distance in the RGB(A) cube.
*
* Parameters:
* im - The image.
* color - The crop color.
* threshold - The crop threshold.
*
* Returns:
* The newly created cropped image, or NULL on failure.
*
* See also:
* - <gdImageCrop>
* - <gdImageCropAuto>
*/
BGD_DECLARE(gdImagePtr) gdImageCropThreshold(gdImagePtr im, const unsigned int color, const float threshold)
{
const int width = gdImageSX(im);
const int height = gdImageSY(im);
int x,y;
int match;
gdRect crop;
crop.x = 0;
crop.y = 0;
crop.width = 0;
crop.height = 0;
/* Pierre: crop everything sounds bad */
if (threshold > 100.0) {
return NULL;
}
if (!gdImageTrueColor(im) && color >= gdImageColorsTotal(im)) {
return NULL;
}
/* TODO: Add gdImageGetRowPtr and works with ptr at the row level
* for the true color and palette images
* new formats will simply work with ptr
*/
match = 1;
for (y = 0; match && y < height; y++) {
for (x = 0; match && x < width; x++) {
match = (gdColorMatch(im, color, gdImageGetPixel(im, x,y), threshold)) > 0;
}
}
/* Whole image would be cropped > bye */
if (match) {
return NULL;
}
crop.y = y - 1;
match = 1;
for (y = height - 1; match && y >= 0; y--) {
for (x = 0; match && x < width; x++) {
match = (gdColorMatch(im, color, gdImageGetPixel(im, x, y), threshold)) > 0;
}
}
crop.height = y - crop.y + 2;
match = 1;
for (x = 0; match && x < width; x++) {
for (y = 0; match && y < crop.y + crop.height; y++) {
match = (gdColorMatch(im, color, gdImageGetPixel(im, x,y), threshold)) > 0;
}
}
crop.x = x - 1;
match = 1;
for (x = width - 1; match && x >= 0; x--) {
for (y = 0; match && y < crop.y + crop.height; y++) {
match = (gdColorMatch(im, color, gdImageGetPixel(im, x,y), threshold)) > 0;
}
}
crop.width = x - crop.x + 2;
return gdImageCrop(im, &crop);
}
/**
* Function: gdImageThresholdCrop
* Crop an image using a given color. The threshold argument defines
* the tolerance to be used while comparing the image color and the
* color to crop. The method used to calculate the color difference
* is based on the color distance in the RGB(a) cube.
*
*
* Parameters:
* im - Source image
* color - color to crop
* threshold - tolerance (0..100)
*
* Returns:
* <gdImagePtr> on success or NULL
*
* See also:
* <gdCropMode>, <gdImageAutoCrop> or <gdImageCrop>
*/
gdImagePtr gdImageCropThreshold(gdImagePtr im, const unsigned int color, const float threshold)
{
const int width = gdImageSX(im);
const int height = gdImageSY(im);
int x,y;
int match;
gdRect crop;
crop.x = 0;
crop.y = 0;
crop.width = 0;
crop.height = 0;
/* Pierre: crop everything sounds bad */
if (threshold > 1.0) {
return NULL;
}
/* TODO: Add gdImageGetRowPtr and works with ptr at the row level
* for the true color and palette images
* new formats will simply work with ptr
*/
match = 1;
for (y = 0; match && y < height; y++) {
for (x = 0; match && x < width; x++) {
match = (gdColorMatch(im, color, gdImageGetPixel(im, x,y), threshold)) > 0;
}
}
/* Pierre
* Nothing to do > bye
* Duplicate the image?
*/
if (y == height - 1) {
return NULL;
}
crop.y = y -1;
match = 1;
for (y = height - 1; match && y >= 0; y--) {
for (x = 0; match && x < width; x++) {
match = (gdColorMatch(im, color, gdImageGetPixel(im, x, y), threshold)) > 0;
}
}
if (y == 0) {
crop.height = height - crop.y + 1;
} else {
crop.height = y - crop.y + 2;
}
match = 1;
for (x = 0; match && x < width; x++) {
for (y = 0; match && y < crop.y + crop.height - 1; y++) {
match = (gdColorMatch(im, color, gdImageGetPixel(im, x,y), threshold)) > 0;
}
}
crop.x = x - 1;
match = 1;
for (x = width - 1; match && x >= 0; x--) {
for (y = 0; match && y < crop.y + crop.height - 1; y++) {
match = (gdColorMatch(im, color, gdImageGetPixel(im, x,y), threshold)) > 0;
}
}
crop.width = x - crop.x + 2;
return gdImageCrop(im, &crop);
}