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PHP - Exif Gpsaltituderef
Hello, I have two photos. According to http://metapicz.com (a website that displays exif data for an image) image1.jpg has a GPSAltitudeRef which is "below sea level". For the second image the GPSAltitudeRef is reported as "above sea level". When I extract the GPS data in PHP for the first image I get...
$exif1 = exif_read_data('image1.jpg', 0, true);
["GPS"]=> array(17) { ["GPSVersion"]=> string(4) "" ["GPSLatitudeRef"]=> string(1) "N" ["GPSLatitude"]=> array(3) { [0]=> string(4) "37/1" [1]=> string(4) "47/1" [2]=> string(10) "42221/1000" } ["GPSLongitudeRef"]=> string(1) "W" ["GPSLongitude"]=> array(3) { [0]=> string(5) "122/1" [1]=> string(4) "23/1" [2]=> string(10) "46896/1000" } ["GPSAltitudeRef"]=> string(1) "" ["GPSAltitude"]=> string(7) "1408/10" ["GPSTimeStamp"]=> array(3) { [0]=> string(3) "4/1" [1]=> string(4) "43/1" [2]=> string(10) "38000/1000" } ["GPSStatus"]=> string(1) "A" ["GPSMeasureMode"]=> string(1) "3" ["GPSSpeedRef"]=> string(1) "K" ["GPSSpeed"]=> string(4) "8/10" ["GPSTrackRef"]=> string(1) "T" ["GPSTrack"]=> string(9) "25135/100" ["GPSMapDatum"]=> string(6) "WGS-84" ["GPSDateStamp"]=> string(10) "2011:07:15" ["GPSDifferential"]=> int(0) }
When I extract the GPS data in PHP for the second image I get...
$exif2 = exif_read_data('image2.jpg', 0, true);
["GPS"]=> array(13) { ["GPSVersion"]=> string(4) "" ["GPSLatitudeRef"]=> string(1) "N" ["GPSLatitude"]=> array(3) { [0]=> string(4) "43/1" [1]=> string(4) "53/1" [2]=> string(8) "2950/100" } ["GPSLongitudeRef"]=> string(1) "W" ["GPSLongitude"]=> array(3) { [0]=> string(4) "79/1" [1]=> string(4) "25/1" [2]=> string(8) "3516/100" } ["GPSAltitudeRef"]=> string(1) "" ["GPSAltitude"]=> string(9) "19650/100" ["GPSTimeStamp"]=> array(3) { [0]=> string(4) "19/1" [1]=> string(3) "9/1" [2]=> string(3) "5/1" } ["GPSDOP"]=> string(10) "14134/1000" ["GPSImgDirectionRef"]=> string(1) "M" ["GPSImgDirection"]=> string(5) "354/1" ["GPSProcessingMode"]=> string(13) "ASCIIfused" ["GPSDateStamp"]=> string(10) "2020:06:24" }
That is all the GPS data extracted for each image. The GPSAltitudeRef for both is " ", that is it's empty. According to other sources on the net if it had a value then (0 = above sea level) and (1= below sea level), but both are empty. How do I (or metapicz.com) determine from that exif data that image1.jpg is "below sea level" and image2.jpg is "above sea level". Thanks Edited August 1, 2020 by SnapSimilar TutorialsIs there a code library out there that can read the exif data from image files, without the use of the php exif extension? I have a Windows hosting package and am noticing that several hosts don't (and won't) enable the exif extension for PHP for some reason. I need Windows for one of my sites which requires MS SQL access, so I can't use a Unix/Linux host because of that. But all of them support PHP on Windows.
Suggestions?
OK, so one of my cameras includes a "Copyright" field in the array returned from the exif data and one doesn't. Does anyone have any ideas how one would test for this field, and if it doesn't exist fill the relevant variable with the copyright info. I have been trying to solve this for a couple of hours now without a great deal of success, what I have is:- Code: [Select] $exif = exif_read_data('thistle.jpg', 'EXIF'); $name = $exif['FileName']; $height = $exif['ExifImageWidth']; $width = $exif['ExifImageLength']; $copy = $exif['Copyright']; $model = $exif['Model']; $exposuretime = $exif['ExposureTime']; $fnumber = $exif['COMPUTED']['ApertureFNumber']; $iso = $exif['ISOSpeedRatings']; $date = $exif['DateTime']; echo "File Name: $name<br />"; echo "Comment: " . $exif['COMMENT'][0] . "<br />"; echo "Height: $height<br />"; echo "Width: $width<br />"; echo "Copyright: $copy<br />"; echo "Camera: $model<br />"; echo "Shutter Speed: $exposuretime<br />"; echo "F number: $fnumber<br />"; echo "ISO: " . $iso . "<br />"; echo "Date & Time: $date<br /><br />"; Whatever I try always seems to end with "Notice: Undefined index: Copyright in C:\wamp\www\php\exif-read.php on line 11" it is obviously Code: [Select] $copy = $exif['Copyright'];that is causing the problem, and I can't work out just how to test for the existence of "Copyright" and head this problem off... OK, so I am trying to read exif data from images and have come up against a snag that I cannot see the answer to. I know that what I have at present is pretty basic, but I want to be sure that I know how to access the bits I want before tidying it up into something more sophisticated. The coide I have is this:- Code: [Select] $exif = exif_read_data('brass jaw.jpg', 'EXIF'); $name = $exif['FileName']; $height = $exif['ExifImageWidth']; $width = $exif['ExifImageLength']; $model = $exif['Model']; $exposuretime = $exif['ExposureTime']; $fnumber = $exif['FNumber']; $iso = $exif['ISOSpeedRatings']; $date = $exif['DateTime']; echo "File Name: $name<br />"; echo "Height: $height<br />"; echo "Width: $width<br />"; echo "Camera: $model<br />"; echo "Shutter Speed: $exposuretime<br />"; echo "F number: $fnumber<br />"; echo "ISO: $iso<br />"; echo "Date & Time: $date<br />"; var_dump($exif); This code produces the following:- File Name: brass jaw.jpg Height: 640 Width: 360 Camera: Canon EOS 550D Shutter Speed: 244/1000000 F number: 8000000/1000000 ISO: Array Date & Time: 2011:09:17 13:52:30 Which serves quite well apart from the ISO, which comes back as "Array". Now when I do a var_dump I see that ISOSpeedRatings returns as this:- 'ISOSpeedRatings' => array 0 => int 800 1 => int 800 What I can't work out is how to access the information from this - I know that the solution will probably be very simple, and that I will end up kicking myself, but I could use a little help. Hi, I want to create a function that reads the exif orientation data of an image and rotates it as required - needs to run before before the resize function here, I'm using GD library if that is relevant:
function resize_gd($sourceFileName, $folder, $destinationFileName, $newWidth, $newHeight, $keepProportion)
{
$newWidth = (int)$newWidth;
$newHeight = (int)$newHeight;
if (!$this->gdInfo >= 1 || !$this->checkGdFileType($sourceFileName)) {
return false;
}
$img = &$this->getImg($sourceFileName);
if ($this->hasError()) {
return false;
}
$srcWidth = ImageSX($img);
$srcHeight = ImageSY($img);
if ( $keepProportion && ($newWidth != 0 && $srcWidth<$newWidth) && ($newHeight!=0 && $srcHeight<$newHeight) ) {
if ($sourceFileName != $folder . $destinationFileName) {
@copy($sourceFileName, $folder . $destinationFileName);
}
return true;
}
if ($keepProportion == true) {
if ($newWidth != 0 && $newHeight != 0) {
$ratioWidth = $srcWidth/$newWidth;
$ratioHeight = $srcHeight/$newHeight;
if ($ratioWidth < $ratioHeight) {
$destWidth = $srcWidth/$ratioHeight;
$destHeight = $newHeight;
} else {
$destWidth = $newWidth;
$destHeight = $srcHeight/$ratioWidth;
}
} else {
if ($newWidth != 0) {
$ratioWidth = $srcWidth/$newWidth;
$destWidth = $newWidth;
$destHeight = $srcHeight/$ratioWidth;
} else if ($newHeight != 0) {
$ratioHeight = $srcHeight/$newHeight;
$destHeight = $newHeight;
$destWidth = $srcWidth/$ratioHeight;
} else {
$destWidth = $srcWidth;
$destHeight = $srcHeight;
}
}
} else {
$destWidth = $newWidth;
$destHeight = $newHeight;
}
$destWidth = round($destWidth);
$destHeight = round($destHeight);
if ($destWidth < 1) $destWidth = 1;
if ($destHeight < 1) $destHeight = 1;
$destImage = &$this->getImageCreate($destWidth, $destHeight);
Edited June 7, 2019 by mcfc4heatons
Hi there, on my yardmaps website, if a user uploads an image taken with an iphone, and the exif data sets orientation to 1, the image is automatically rotated when put through the imagecopyresampled function. If I take the same image, and strip out the exif data with photoshop (save as for web, no meta data), the image uploads correctly. Is there any way to force imagecopyresampled to not rotate the image? Thanks B |
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