Question

wp_read_image_metadata( string $file )

Get extended image metadata, exif or iptc as available.

---

description

Retrieves the EXIF metadata aperture, credit, camera, caption, copyright, iso created_timestamp, focal_length, shutter_speed, and title.

The IPTC metadata that is retrieved is APP13, credit, byline, created date and time, caption, copyright, and title. Also includes FNumber, Model, DateTimeDigitized, FocalLength, ISOSpeedRatings, and ExposureTime.

---

参数

$file

(string) (Required)

---

返回值

(bool|array) False on failure. Image metadata array on success.

---

源代码

File: wp-admin/includes/image.php

function wp_read_image_metadata( $file ) {
	if ( ! file_exists( $file ) )
		return false;

	list( , , $源代码ImageType ) = getimagesize( $file );

	/*
	 * EXIF contains a bunch of data we'll probably never need formatted in ways
	 * that are difficult to use. We'll normalize it and just extract the fields
	 * that are likely to be useful. Fractions and numbers are converted to
	 * floats, dates to unix timestamps, and everything else to strings.
	 */
	$meta = array(
		'aperture' => 0,
		'credit' => '',
		'camera' => '',
		'caption' => '',
		'created_timestamp' => 0,
		'copyright' => '',
		'focal_length' => 0,
		'iso' => 0,
		'shutter_speed' => 0,
		'title' => '',
		'orientation' => 0,
		'keywords' => array(),
	);

	$iptc = array();
	/*
	 * Read IPTC first, since it might contain data not available in exif such
	 * as caption, description etc.
	 */
	if ( is_callable( 'iptcparse' ) ) {
		getimagesize( $file, $info );

		if ( ! empty( $info['APP13'] ) ) {
			$iptc = iptcparse( $info['APP13'] );

			// Headline, "A brief synopsis of the caption."
			if ( ! empty( $iptc['2#105'][0] ) ) {
				$meta['title'] = trim( $iptc['2#105'][0] );
			/*
			 * Title, "Many use the Title field to store the filename of the image,
			 * though the field may be used in many ways."
			 */
			} elseif ( ! empty( $iptc['2#005'][0] ) ) {
				$meta['title'] = trim( $iptc['2#005'][0] );
			}

			if ( ! empty( $iptc['2#120'][0] ) ) { // description / legacy caption
				$caption = trim( $iptc['2#120'][0] );

				mbstring_binary_safe_encoding();
				$caption_length = strlen( $caption );
				reset_mbstring_encoding();

				if ( empty( $meta['title'] ) && $caption_length < 80 ) {
					// Assume the title is stored in 2:120 if it's short.
					$meta['title'] = $caption;
				}

				$meta['caption'] = $caption;
			}

			if ( ! empty( $iptc['2#110'][0] ) ) // credit
				$meta['credit'] = trim( $iptc['2#110'][0] );
			elseif ( ! empty( $iptc['2#080'][0] ) ) // creator / legacy byline
				$meta['credit'] = trim( $iptc['2#080'][0] );

			if ( ! empty( $iptc['2#055'][0] ) && ! empty( $iptc['2#060'][0] ) ) // created date and time
				$meta['created_timestamp'] = strtotime( $iptc['2#055'][0] . ' ' . $iptc['2#060'][0] );

			if ( ! empty( $iptc['2#116'][0] ) ) // copyright
				$meta['copyright'] = trim( $iptc['2#116'][0] );

			if ( ! empty( $iptc['2#025'][0] ) ) { // keywords array
				$meta['keywords'] = array_values( $iptc['2#025'] );
			}
		 }
	}

	/**
	 * Filters the image types to check for exif data.
	 *
	 * @since 2.5.0
	 *
	 * @param array $image_types Image types to check for exif data.
	 */
	if ( is_callable( 'exif_read_data' ) && in_array( $源代码ImageType, apply_filters( 'wp_read_image_metadata_types', array( IMAGETYPE_JPEG, IMAGETYPE_TIFF_II, IMAGETYPE_TIFF_MM ) ) ) ) {
		$exif = @exif_read_data( $file );

		if ( ! empty( $exif['Imagedescription'] ) ) {
			mbstring_binary_safe_encoding();
			$description_length = strlen( $exif['Imagedescription'] );
			reset_mbstring_encoding();

			if ( empty( $meta['title'] ) && $description_length < 80 ) {
				// Assume the title is stored in Imagedescription
				$meta['title'] = trim( $exif['Imagedescription'] );
			}

			if ( empty( $meta['caption'] ) && ! empty( $exif['COMPUTED']['UserComment'] ) ) {
				$meta['caption'] = trim( $exif['COMPUTED']['UserComment'] );
			}

			if ( empty( $meta['caption'] ) ) {
				$meta['caption'] = trim( $exif['Imagedescription'] );
			}
		} elseif ( empty( $meta['caption'] ) && ! empty( $exif['Comments'] ) ) {
			$meta['caption'] = trim( $exif['Comments'] );
		}

		if ( empty( $meta['credit'] ) ) {
			if ( ! empty( $exif['Artist'] ) ) {
				$meta['credit'] = trim( $exif['Artist'] );
			} elseif ( ! empty($exif['Author'] ) ) {
				$meta['credit'] = trim( $exif['Author'] );
			}
		}

		if ( empty( $meta['copyright'] ) && ! empty( $exif['Copyright'] ) ) {
			$meta['copyright'] = trim( $exif['Copyright'] );
		}
		if ( ! empty( $exif['FNumber'] ) ) {
			$meta['aperture'] = round( wp_exif_frac2dec( $exif['FNumber'] ), 2 );
		}
		if ( ! empty( $exif['Model'] ) ) {
			$meta['camera'] = trim( $exif['Model'] );
		}
		if ( empty( $meta['created_timestamp'] ) && ! empty( $exif['DateTimeDigitized'] ) ) {
			$meta['created_timestamp'] = wp_exif_date2ts( $exif['DateTimeDigitized'] );
		}
		if ( ! empty( $exif['FocalLength'] ) ) {
			$meta['focal_length'] = (string) wp_exif_frac2dec( $exif['FocalLength'] );
		}
		if ( ! empty( $exif['ISOSpeedRatings'] ) ) {
			$meta['iso'] = is_array( $exif['ISOSpeedRatings'] ) ? reset( $exif['ISOSpeedRatings'] ) : $exif['ISOSpeedRatings'];
			$meta['iso'] = trim( $meta['iso'] );
		}
		if ( ! empty( $exif['ExposureTime'] ) ) {
			$meta['shutter_speed'] = (string) wp_exif_frac2dec( $exif['ExposureTime'] );
		}
		if ( ! empty( $exif['Orientation'] ) ) {
			$meta['orientation'] = $exif['Orientation'];
		}
	}

	foreach ( array( 'title', 'caption', 'credit', 'copyright', 'camera', 'iso' ) as $key ) {
		if ( $meta[ $key ] && ! seems_utf8( $meta[ $key ] ) ) {
			$meta[ $key ] = utf8_encode( $meta[ $key ] );
		}
	}

	foreach ( $meta['keywords'] as $key => $keyword ) {
		if ( ! seems_utf8( $keyword ) ) {
			$meta['keywords'][ $key ] = utf8_encode( $keyword );
		}
	}

	$meta = wp_kses_post_deep( $meta );

	/**
	 * Filters the array of meta data read from an image's exif data.
	 *
	 * @since 2.5.0
	 * @since 4.4.0 The `$iptc` parameter was added.
	 *
	 * @param array  $meta            Image meta data.
	 * @param string $file            Path to image file.
	 * @param int    $源代码ImageType Type of image.
	 * @param array  $iptc            IPTC data.
	 */
	return apply_filters( 'wp_read_image_metadata', $meta, $file, $源代码ImageType, $iptc );

}

---

更新日志

Version	description
2.5.0	Introduced.

---

相关函数

Uses

• wp-includes/kses.php: wp_kses_post_deep()
• wp-admin/includes/image.php: wp_exif_frac2dec()
• wp-admin/includes/image.php: wp_exif_date2ts()
• wp-admin/includes/image.php: wp_read_image_metadata_types
• wp-admin/includes/image.php: wp_read_image_metadata
• wp-includes/formatting.php: seems_utf8()
• wp-includes/functions.php: mbstring_binary_safe_encoding()
• wp-includes/functions.php: reset_mbstring_encoding()
• wp-includes/plugin.php: apply_filters()
Show 4 more uses Hide more uses

---

Used By

• wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php: WP_REST_Attachments_Controller::create_item()
• wp-admin/includes/image.php: wp_generate_attachment_metadata()
• wp-admin/includes/media.php: media_handle_upload()
• wp-admin/includes/media.php: media_handle_sideload()

---

User Contributed Notes

1. Skip to note content You must log in to vote on the helpfulness of this noteVote results for this note: 0You must log in to vote on the helpfulness of this note Contributed by Codex

   Additional note to Return

   The elements returned in the array are:

   ["aperture"]
   (string) Set to the EXIF FNumber field.

   ["credit"]
   (string) Set to the first non-empty value found by looking through the following fields:

   1. IPTC Credit field (2#110)
   2. IPTC Creator field (2#080)
   3. EXIF Artist field
   4. EXIF Author field

   ["camera"]
   (string) Set to the EXIF Model field.

   ["caption"]
   (string) Set to a non-empty value of one of the following fields (see 源代码 code for the precise logic involved):

   1. IPTC description field (2#120)
   2. EXIF UserComment field if [“title”] is unset AND EXIF:Imagedescription is less than 80 characters
   3. EXIF Imagedescription field if [“title”] is set OR EXIF:Imagedescription is more than 80 characters
   4. EXIF Comments field if [“title”] does not equal EXIF:Comments

   ["created_timestamp"]
   (string) Set to the first non-empty value found by looking through the following fields:

   1. EXIF field DateTimeDigitized
   2. IPTC Date and Time fields (2#055 and 2#060)

   ["copyright"]
   (string) Set to the first non-empty value found by looking through the following fields:

   1. IPTC Copyright field (2#116)
   2. EXIF Copyright field

   ["focal_length"]
   (string) Set to the EXIF FocalLength field.

   ["iso"]
   (string) Set to the EXIF ISOSpeedRatings field.

   ["shutter_speed"]
   (string) Set to the EXIF ExposureTime field.

   ["title"]
   (string) Set to the first non-empty value found by looking through the following fields:

   1. IPTC Headline field (2#105)
   2. IPTC Title field (2#005)
   3. IPTC description field (2#120) but only if less than 80 characters
   4. EXIF Title field
   5. EXIF Imagedescription field but only if less than 80 characters

   The (2#nnn) value shown after each IPTC field (above) is the key of the array returned by PHP’s iptcparse function for that particular IPTC field.

When you receive error upon calling this function

PHP Fatal error: Uncaught Error: Call to undefined function wp_read_image_metadata() ...

Make sure to include the wp-admin/includes/image.php file

require_once ABSPATH . '/wp-admin/includes/image.php';

$path = '/path/to/file.jpg';

wp_read_image_metadata( $path );