How to read and edit an image's metadata using the php extension ImageExif

How to use PHP extension ImageExif to read and edit image metadata

Introduction:
Image metadata is additional information about an image, including shooting date, camera settings, geographical location, etc. . These metadata are very important for image management and processing. In PHP, we can use the ImageExif extension to read and edit the metadata of an image.

Introduction:
ImageExif is an extension officially provided by PHP, which allows us to read and edit the Exif (Exchangeable Image File Format) metadata of images. Exif metadata is often embedded in images in formats such as jpg and tif. Using the ImageExif extension, we can easily read and edit this metadata.

Read the Exif information of the image:
First, we need to confirm that the ImageExif extension has been installed and enabled. You can confirm whether it is enabled by looking for "exif" in the PHP configuration file. If it is not enabled, you can enable it in the extension manager or recompile PHP.

The following is an example that demonstrates how to read the Exif information of an image:

$imagePath = 'test.jpg';
$exifData = exif_read_data($imagePath, 'EXIF');

echo "拍摄时间: " . $exifData['DateTimeOriginal'] . "
";
echo "相机品牌: " . $exifData['Make'] . "
";
echo "相机型号: " . $exifData['Model'] . "
";
echo "焦距: " . $exifData['FocalLength'] . "mm
";
echo "曝光时间: " . $exifData['ExposureTime'] . "秒
";
echo "ISO感光度: " . $exifData['ISOSpeedRatings'] . "
";

Edit the Exif information of an image:
If we need to edit the Exif information of an image, we can use the ImageExif extension Provided functions to operate. The following is an example that demonstrates how to edit the Exif information of an image:

$imagePath = 'test.jpg';
$exifData = exif_read_data($imagePath, 'EXIF');

$exifData['DateTimeOriginal'] = '2022-01-01 12:00:00';
$exifData['Make'] = 'Canon';
$exifData['Model'] = 'EOS 5D Mark IV';
$exifData['FocalLength'] = '50/1';
$exifData['ExposureTime'] = '1/100';
$exifData['ISOSpeedRatings'] = '400';

exif_write_data($exifData, $imagePath);

Note: Before editing the Exif information of an image, we need to read the original Exif information and save it in a variable. After editing, use the exif_write_data function to write the modified Exif information to the image.

Conclusion:
Using the ImageExif extension, we can easily read and edit the metadata of images. This is very useful for image management and processing. I hope this article is helpful to you, please leave a message to communicate.

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