diff --git a/leaf.php b/leaf.php
index d84e384..3397ba1 100644
--- a/leaf.php
+++ b/leaf.php
@@ -343,7 +343,7 @@ foreach ($picks as $file) {
 	$parts = chop(shell_exec("exiftool -s -s -s -XMP-crs:CropTop -XMP-crs:CropRight -XMP-crs:CropLeft -XMP-crs:CropBottom ".$file." 2>&1"));
 	@list($top, $right, $left, $bottom) = explode("\n", $parts);
 	if ($top && $right && $left && $bottom) {
-		$key = filter_var(substr(basename($file), 4), FILTER_SANITIZE_NUMBER_INT);
+		$key = abs(filter_var(substr(basename($file), 4), FILTER_SANITIZE_NUMBER_INT));
 		$crops[$key]['top'] = $top;
 		$crops[$key]['right'] = $right;
 		$crops[$key]['left'] = $left;
@@ -513,7 +513,7 @@ echo Welcome("Display brightness values for a directory of images");
 
 $files = glob(args("dir")."*.*");
 foreach ($files as $file) {
-	echo $file.": ".filter_var(shell_exec("convert ".$file." -colorspace Gray -format \"%[fx:quantumrange*image.mean]\" info:"),FILTER_SANITIZE_NUMBER_INT)."\n";
+	echo $file.": ".abs(filter_var(shell_exec("convert ".$file." -colorspace Gray -format \"%[fx:quantumrange*image.mean]\" info:"),FILTER_SANITIZE_NUMBER_INT))."\n";
 	}
 
 fin();
@@ -1171,7 +1171,7 @@ if (args("m")) {
 	} else {
 	$mid = $files[ceil(count($files)/2)];
 	echo "Guessing midpoint key from ".$mid."\n";
-	$midpoint_key = filter_var($mid, FILTER_SANITIZE_NUMBER_INT);
+	$midpoint_key = abs(filter_var($mid, FILTER_SANITIZE_NUMBER_INT));
 	}
 	
 $e = 2; $o = 1;
@@ -1300,7 +1300,7 @@ $files = glob(args("dir")."*.*");
 if ($multicrops > 1) {
 
 	foreach ($files as $file) {
-		$key = filter_var(substr(basename($file), 4), FILTER_SANITIZE_NUMBER_INT);
+		$key = abs(filter_var(substr(basename($file), 4), FILTER_SANITIZE_NUMBER_INT));
 		$seq[$key] = $file; 
 		}
 	ksort($seq);
@@ -1332,7 +1332,7 @@ foreach ($picks as $file) {
 	$parts = chop(shell_exec("exiftool -s -s -s -XMP-crs:CropTop -XMP-crs:CropRight -XMP-crs:CropLeft -XMP-crs:CropBottom ".$file." 2>&1"));
 	@list($top, $right, $left, $bottom) = explode("\n", $parts);
 	if ($top && $right && $left && $bottom) {
-		$key = filter_var(substr(basename($file), 4), FILTER_SANITIZE_NUMBER_INT);
+		$key = abs(filter_var(substr(basename($file), 4), FILTER_SANITIZE_NUMBER_INT));
 		$crops[$key]['top'] = $top;
 		$crops[$key]['right'] = $right;
 		$crops[$key]['left'] = $left;
@@ -1354,7 +1354,7 @@ foreach ($crops as $key => $parts) {
 ask("");
 echo "Crop Mapping:\n";
 foreach ($files as $file) {
-	$key = filter_var(substr(basename($file), 4), FILTER_SANITIZE_NUMBER_INT);
+	$key = abs(filter_var(substr(basename($file), 4), FILTER_SANITIZE_NUMBER_INT));
 	$closekey = getClosest($key, array_keys($crops));
 	$parts = $crops[$closekey];
 	echo "\n";
@@ -1413,8 +1413,8 @@ echo "Comparing phash values: ";
 
 foreach ($tnfiles as $file) {
 	foreach ($tnfiles as $nfile) {
-		$anum = filter_var($file, FILTER_SANITIZE_NUMBER_INT); 
-		$bnum = filter_var($nfile, FILTER_SANITIZE_NUMBER_INT); 
+		$anum = abs(filter_var($file, FILTER_SANITIZE_NUMBER_INT)); 
+		$bnum = abs(filter_var($nfile, FILTER_SANITIZE_NUMBER_INT)); 
 		$diff = abs($anum-$bnum);
 		$done[$file][$nfile] = 1;
 		if ($file != $nfile && $diff < $walk && isset($done[$nfile][$file])) {