I am trying to port over the below PHP function to Python. However I am receiving the following error: line 189, in detectOnSubImage rect = rects[i_rect] IndexError: list index out of range
Rects receives the list located at current_node[1]
rects = current_node[1]
And the while loop would not go out of range past the length of the list rects
while i_rect < len(rects):
i_rect = i_rect+1
rect = rects[i_rect]
What did I miss when porting over this PHP function to Python and what would be the correct Python code equivalent?
PHP code: (below)
protected function detectOnSubImage($x, $y, $scale, $ii, $ii2, $w, $iiw, $inv_area)
{
$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;
}
}
Python code: (below)
def detectOnSubImage(self, 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 = sqrt(vnorm) if vnorm > 1 else 1
#var foo = (test) ? "True" : "False";
#foo = "True" if test else "False"
passed = True
#for i_stage in xrange(0, i_stage < (len(self.detection_data)), i_stage= i_stage+1):
i_stage=0
while i_stage < len(self.detection_data):
i_stage= i_stage+1
stage = self.detection_data[i_stage]
trees = stage[0]
stage_thresh = stage[1]
stage_sum = 0
#for i_tree in xrange( 0, i_tree < len(trees), i_tree= i_tree+1):
i_tree=0
while i_tree < len(trees):
i_tree= i_tree+1
tree = trees[i_tree]
current_node = tree[0]
tree_sum = 0
while (current_node != None):
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 in xrange(0, i_rect < len(rects), i_rect = i_rec+1):
i_rect = 0
while i_rect < len(rects):
i_rect = i_rect+1
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 = rect_sum + r_sum
rect_sum = rect_sum * inv_area
current_node = None
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 = stage_sum + tree_sum
if (stage_sum < stage_thresh):
return false
return True
Here is the tree structure and other var_dumps from within the PHP code which shows a multi-dimensional array
$tree = $trees[0]
array(2) { [0]=> array(2) { [0]=> array(5) { [0]=> float(0.00432723) [1]=> float(0.0383819) [2]=> float(-1) [3]=> int(-1) [4]=> int(1) } [1]=> array(2) { [0]=> array(5) { [0]=> int(2) [1]=> int(7) [2]=> int(16) [3]=> int(4) [4]=> int(-1) } [1]=> array(5) { [0]=> int(2) [1]=> int(9) [2]=> int(16) [3]=> int(2) [4]=> int(2) } } } [1]=> array(2) { [0]=> array(5) { [0]=> float(0.0130762) [1]=> float(0.896526) [2]=> float(0.262931) [3]=> int(-1) [4]=> int(-1) } [1]=> array(2) { [0]=> array(5) { [0]=> int(8) [1]=> int(4) [2]=> int(3) [3]=> int(14) [4]=> int(-1) } [1]=> array(5) { [0]=> int(8) [1]=> int(11) [2]=> int(3) [3]=> int(7) [4]=> int(2) } } } }
$current_node = $tree[0]
array(2) { [0]=> array(5) { [0]=> float(0.00432723) [1]=> float(0.0383819) [2]=> float(-1) [3]=> int(-1) [4]=> int(1) } [1]=> array(2) { [0]=> array(5) { [0]=> int(2) [1]=> int(7) [2]=> int(16) [3]=> int(4) [4]=> int(-1) } [1]=> array(5) { [0]=> int(2) [1]=> int(9) [2]=> int(16) [3]=> int(2) [4]=> int(2) } } }
$vals = $current_node[0]
array(5) { [0]=> float(0.00432723) [1]=> float(0.0383819) [2]=> float(-1) [3]=> int(-1) [4]=> int(1) }
$rects = $current_node[1]
array(2) { [0]=> array(5) { [0]=> int(2) [1]=> int(7) [2]=> int(16) [3]=> int(4) [4]=> int(-1) } [1]=> array(5) { [0]=> int(2) [1]=> int(9) [2]=> int(16) [3]=> int(2) [4]=> int(2) } }
$rect = $rects[0]
array(5) { [0]=> int(2) [1]=> int(7) [2]=> int(16) [3]=> int(4) [4]=> int(-1) }
To debug this, I recommend printing out the entire structure of the tree and trees variables (and others) within Python and in the PHP code. This will let you compare what assignments and indexing you need to do to make the code compatible. I have had issues in the past where it was just a matter of adding one more [0] to the end of an array assignment, because it was nested one level deeper in the PHP or JSON or whatever than I anticipated.
Good luck!