12
有谁知道在PHP中进行人脸检测的好方法吗？ I came across some code here声称这样做，但我似乎无法让它正常工作。我想做这个工作（尽管它会很慢），任何帮助你可以给我会非常感激。PHP中的人脸检测
下面是来自链接代码：
<?php
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// @Author Karthik Tharavaad
// [email protected]
// @Contributor Maurice Svay
// [email protected]
class Face_Detector {
protected $detection_data;
protected $canvas;
protected $face;
private $reduced_canvas;
public function __construct($detection_file = 'detection.dat') {
if (is_file($detection_file)) {
$this->detection_data = unserialize(file_get_contents($detection_file));
} else {
throw new Exception("Couldn't load detection data");
}
//$this->detection_data = json_decode(file_get_contents('data.js'));
}
public function face_detect($file) {
if (!is_file($file)) {
throw new Exception("Can not load $file");
}
$this->canvas = imagecreatefromjpeg($file);
$im_width = imagesx($this->canvas);
$im_height = imagesy($this->canvas);
//Resample before detection?
$ratio = 0;
$diff_width = 320 - $im_width;
$diff_height = 240 - $im_height;
if ($diff_width > $diff_height) {
$ratio = $im_width/320;
} else {
$ratio = $im_height/240;
}
if ($ratio != 0) {
$this->reduced_canvas = imagecreatetruecolor($im_width/$ratio, $im_height/$ratio);
imagecopyresampled($this->reduced_canvas, $this->canvas, 0, 0, 0, 0, $im_width/$ratio, $im_height/$ratio, $im_width, $im_height);
$stats = $this->get_img_stats($this->reduced_canvas);
$this->face = $this->do_detect_greedy_big_to_small($stats['ii'], $stats['ii2'], $stats['width'], $stats['height']);
$this->face['x'] *= $ratio;
$this->face['y'] *= $ratio;
$this->face['w'] *= $ratio;
} else {
$stats = $this->get_img_stats($this->canvas);
$this->face = $this->do_detect_greedy_big_to_small($stats['ii'], $stats['ii2'], $stats['width'], $stats['height']);
}
return ($this->face['w'] > 0);
}
public function toJpeg() {
$color = imagecolorallocate($this->canvas, 255, 0, 0); //red
imagerectangle($this->canvas, $this->face['x'], $this->face['y'], $this->face['x']+$this->face['w'], $this->face['y']+ $this->face['w'], $color);
header('Content-type: image/jpeg');
imagejpeg($this->canvas);
}
public function toJson() {
return "{'x':" . $this->face['x'] . ", 'y':" . $this->face['y'] . ", 'w':" . $this->face['w'] . "}";
}
public function getFace() {
return $this->face;
}
protected function get_img_stats($canvas){
$image_width = imagesx($canvas);
$image_height = imagesy($canvas);
$iis = $this->compute_ii($canvas, $image_width, $image_height);
return array(
'width' => $image_width,
'height' => $image_height,
'ii' => $iis['ii'],
'ii2' => $iis['ii2']
);
}
protected function compute_ii($canvas, $image_width, $image_height){
$ii_w = $image_width+1;
$ii_h = $image_height+1;
$ii = array();
$ii2 = array();
for($i=0; $i<$ii_w; $i++){
$ii[$i] = 0;
$ii2[$i] = 0;
}
for($i=1; $i<$ii_w; $i++){
$ii[$i*$ii_w] = 0;
$ii2[$i*$ii_w] = 0;
$rowsum = 0;
$rowsum2 = 0;
for($j=1; $j<$ii_h; $j++){
$rgb = ImageColorAt($canvas, $j, $i);
$red = ($rgb >> 16) & 0xFF;
$green = ($rgb >> 8) & 0xFF;
$blue = $rgb & 0xFF;
$grey = (0.2989*$red + 0.587*$green + 0.114*$blue)>>0; // this is what matlab uses
$rowsum += $grey;
$rowsum2 += $grey*$grey;
$ii_above = ($i-1)*$ii_w + $j;
$ii_this = $i*$ii_w + $j;
$ii[$ii_this] = $ii[$ii_above] + $rowsum;
$ii2[$ii_this] = $ii2[$ii_above] + $rowsum2;
}
}
return array('ii'=>$ii, 'ii2' => $ii2);
}
protected function do_detect_greedy_big_to_small($ii, $ii2, $width, $height){
$s_w = $width/20.0;
$s_h = $height/20.0;
$start_scale = $s_h < $s_w ? $s_h : $s_w;
$scale_update = 1/1.2;
for($scale = $start_scale; $scale > 1; $scale *= $scale_update){
$w = (20*$scale) >> 0;
$endx = $width - $w - 1;
$endy = $height - $w - 1;
$step = max($scale, 2) >> 0;
$inv_area = 1/($w*$w);
for($y = 0; $y < $endy ; $y += $step){
for($x = 0; $x < $endx ; $x += $step){
$passed = $this->detect_on_sub_image($x, $y, $scale, $ii, $ii2, $w, $width+1, $inv_area);
if($passed) {
return array('x'=>$x, 'y'=>$y, 'w'=>$w);
}
} // end x
} // end y
} // end scale
return null;
}
protected function detect_on_sub_image($x, $y, $scale, $ii, $ii2, $w, $iiw, $inv_area){
$mean = ($ii[($y+$w)*$iiw + $x + $w] + $ii[$y*$iiw+$x] - $ii[($y+$w)*$iiw+$x] - $ii[$y*$iiw+$x+$w] )*$inv_area;
$vnorm = ($ii2[($y+$w)*$iiw + $x + $w] + $ii2[$y*$iiw+$x] - $ii2[($y+$w)*$iiw+$x] - $ii2[$y*$iiw+$x+$w] )*$inv_area - ($mean*$mean);
$vnorm = $vnorm > 1 ? sqrt($vnorm) : 1;
$passed = true;
for($i_stage = 0; $i_stage < count($this->detection_data); $i_stage++){
$stage = $this->detection_data[$i_stage];
$trees = $stage[0];
$stage_thresh = $stage[1];
$stage_sum = 0;
for($i_tree = 0; $i_tree < count($trees); $i_tree++){
$tree = $trees[$i_tree];
$current_node = $tree[0];
$tree_sum = 0;
while($current_node != null){
$vals = $current_node[0];
$node_thresh = $vals[0];
$leftval = $vals[1];
$rightval = $vals[2];
$leftidx = $vals[3];
$rightidx = $vals[4];
$rects = $current_node[1];
$rect_sum = 0;
for($i_rect = 0; $i_rect < count($rects); $i_rect++){
$s = $scale;
$rect = $rects[$i_rect];
$rx = ($rect[0]*$s+$x)>>0;
$ry = ($rect[1]*$s+$y)>>0;
$rw = ($rect[2]*$s)>>0;
$rh = ($rect[3]*$s)>>0;
$wt = $rect[4];
$r_sum = ($ii[($ry+$rh)*$iiw + $rx + $rw] + $ii[$ry*$iiw+$rx] - $ii[($ry+$rh)*$iiw+$rx] - $ii[$ry*$iiw+$rx+$rw])*$wt;
$rect_sum += $r_sum;
}
$rect_sum *= $inv_area;
$current_node = null;
if($rect_sum >= $node_thresh*$vnorm){
if($rightidx == -1)
$tree_sum = $rightval;
else
$current_node = $tree[$rightidx];
} else {
if($leftidx == -1)
$tree_sum = $leftval;
else
$current_node = $tree[$leftidx];
}
}
$stage_sum += $tree_sum;
}
if($stage_sum < $stage_thresh){
return false;
}
}
return true;
}
}
用法：
$detector = new Face_Detector('detection.dat');
$detector->face_detect('maurice_svay_150.jpg');
$detector->toJpeg();
我遇到的问题，似乎在页面上的注释中来了也。 “imagecolorat（）[function.imagecolorat]：320,1超出范围。”所以，我在文件的顶部添加了一个error_reporting（0）（不是真正的解决方案），而且有时它似乎有效，而其他时候它不会执行任何操作。
有什么想法？
可能重复ction PHP或软件的照片和视频画廊]（http://stackoverflow.com/questions/1210672/facial-recognition-detection-php-or-software-for-photo-and-video-galleries） – Gordon 2010-11-12 08:20:05