library/Zebra_Image.php
<?php
/**
* Methods used with the {@link resize()} method.
*/
define('ZEBRA_IMAGE_BOXED', 0);
define('ZEBRA_IMAGE_NOT_BOXED', 1);
define('ZEBRA_IMAGE_CROP_TOPLEFT', 2);
define('ZEBRA_IMAGE_CROP_TOPCENTER', 3);
define('ZEBRA_IMAGE_CROP_TOPRIGHT', 4);
define('ZEBRA_IMAGE_CROP_MIDDLELEFT', 5);
define('ZEBRA_IMAGE_CROP_CENTER', 6);
define('ZEBRA_IMAGE_CROP_MIDDLERIGHT', 7);
define('ZEBRA_IMAGE_CROP_BOTTOMLEFT', 8);
define('ZEBRA_IMAGE_CROP_BOTTOMCENTER', 9);
define('ZEBRA_IMAGE_CROP_BOTTOMRIGHT', 10);
// this enables handling of partially broken JPEG files without warnings/errors
ini_set('gd.jpeg_ignore_warning', true);
/**
* A compact (one-file only) and lightweight PHP library for image manipulation providing methods for performing several
* types of image manipulation operations and applying filters to images.
*
* Read more {@link https://github.com/stefangabos/Zebra_Image/ here}
*
* @author Stefan Gabos <contact@stefangabos.ro>
* @version 2.3.0 (last revision: June 06, 2019)
* @copyright (c) 2006 - 2019 Stefan Gabos
* @license https://www.gnu.org/licenses/lgpl-3.0.txt GNU LESSER GENERAL PUBLIC LICENSE
* @package Zebra_Image
*/
class Zebra_Image
{
/**
* Indicates the file system permissions to be set for newly created images.
*
* Better is to leave this setting as it is.
*
* If you know what you are doing, here is how you can calculate the permission levels:
*
* - 400 Owner Read
* - 200 Owner Write
* - 100 Owner Execute
* - 40 Group Read
* - 20 Group Write
* - 10 Group Execute
* - 4 Global Read
* - 2 Global Write
* - 1 Global Execute
*
* Default is 0755
*
* @var integer
*/
public $chmod_value;
/**
* If set to FALSE, images having both width and height smaller than the required width and height, will be left
* untouched ({@link jpeg_quality} and {@link png_compression} will still apply).
*
* Available only for the {@link resize()} method
*
* Default is TRUE
*
* @var boolean
*/
public $enlarge_smaller_images;
/**
* In case of an error read this property's value to see the error's code.
*
* Possible error codes are:
*
* - 1: source file could not be found
* - 2: source file is not readable
* - 3: could not write target file
* - 4: unsupported source file format
* - 5: unsupported target file format
* - 6: GD library version does not support target file format
* - 7: GD library is not installed!
* - 8: "chmod" command is disabled via configuration
* - 9: "exif_read_data" function is not available
*
* Default is 0 (no error).
*
* @var integer
*/
public $error;
/**
* If set to TRUE, JPEG images will be auto-rotated according to the {@link http://keyj.emphy.de/exif-orientation-rant/ Exif Orientation Tag}
* so that they are always shown correctly.
*
* <samp>If you set this to TRUE you must also enable exif-support with --enable-exif. Windows users must enable both
* the php_mbstring.dll and php_exif.dll DLL's in php.ini. The php_mbstring.dll DLL must be loaded before the
* php_exif.dll DLL so adjust your php.ini accordingly. See {@link http://php.net/manual/en/exif.installation.php the PHP manual}</samp>
*
* Default is FALSE
*
* @since 2.2.4
*
* @var boolean
*/
public $auto_handle_exif_orientation;
/**
* Indicates the quality of the output image (better quality means bigger file size).
*
* Used only if the file at {@link target_path} is a JPG/JPEG image.
*
* Range is 0 - 100
*
* Default is 85
*
* @var integer
*/
public $jpeg_quality;
/**
* Indicates the compression level of the output image (lower compression means bigger file size).
*
* Available only if PHP version is 5.1.2+, and only if the file at {@link target_path} is a PNG image. It will be
* ignored otherwise.
*
* Range is 0 - 9
*
* Default is 9
*
* @since 2.2
*
* @var integer
*/
public $png_compression;
/**
* Specifies whether, upon resizing, images should preserve their aspect ratio.
*
* Available only for the {@link resize()} method
*
* Default is TRUE
*
* @var boolean
*/
public $preserve_aspect_ratio;
/**
* Indicates whether a target files should preserve the source file's date/time.
*
* Default is TRUE
*
* @since 1.0.4
*
* @var boolean
*/
public $preserve_time;
/**
* Indicates whether the target image should have a "sharpen" filter applied to it.
*
* Can be very useful when creating thumbnails and should be used only when creating thumbnails.
*
* <i>The sharpen filter relies on the "imageconvolution" PHP function which is available only for PHP version
* 5.1.0+, and will leave the images unaltered for older versions!</i>
*
* Default is FALSE
*
* @since 2.2
*
* @var boolean
*/
public $sharpen_images;
/**
* Path to an image file to apply the transformations to.
*
* Supported file types are <b>GIF</b>, <b>PNG</b> and <b>JPEG</b>.
*
* @var string
*/
public $source_path;
/**
* Path (including file name) to where to save the transformed image.
*
* <i>Can be a different than {@link source_path} - the type of the transformed image will be as indicated by the
* file's extension (supported file types are GIF, PNG and JPEG)</i>.
*
* @var string
*/
public $target_path;
/**
* Constructor of the class.
*
* Initializes the class and the default properties
*
* @return void
*/
public function __construct()
{
// set default values for properties
$this->chmod_value = 0755;
$this->error = 0;
$this->jpeg_quality = 85;
$this->png_compression = 9;
$this->preserve_aspect_ratio = $this->preserve_time = $this->enlarge_smaller_images = true;
$this->sharpen_images = $this->auto_handle_exif_orientation = false;
$this->source_path = $this->target_path = '';
}
/**
* Applies one or more filters to the image given as {@link source_path} and outputs it as the file specified as
* {@link target_path}.
*
* <samp>This method is available only if the {@link http://php.net/manual/en/function.imagefilter.php imagefilter}
* function is available (available from PHP 5+), and will leave images unaltered otherwise.</samp>
*
* <code>
* // include the Zebra_Image library
* require 'path/to/Zebra_Image.php';
*
* // instantiate the class
* $img = new Zebra_Image();
*
* // a source image
* $img->source_path = 'path/to/source.ext';
*
* // path to where should the resulting image be saved
* // note that by simply setting a different extension to the file will
* // instruct the script to create an image of that particular type
* $img->target_path = 'path/to/target.ext';
*
* // apply the "grayscale" filter
* $img->apply_filter('grayscale');
*
* // apply the "contrast" filter
* $img->apply_filter('contrast', -20);
* </code>
*
* You can also apply multiple filters at once. In this case, the method requires a single argument, an array of
* arrays, containing the filters and associated arguments, where applicable:
*
* <code>
* // create a sepia effect
* // note how we're applying multiple filters at once
* // each filter is in its own array
* $img->apply_filter(array(
*
* // first we apply the "grayscale" filter
* array('grayscale'),
*
* // then we apply the "colorize" filter with 90, 60, 40 as
* // the values for red, green and blue
* array('colorize', 90, 60, 40),
*
* ));
* </code>
*
* @param string $filter The (case-insensitive) name of the filter to apply. Can be one of the following:
*
* - <b>brightness</b> - changes the brightness of the image; use <b>arg1</b>
* to set the level of brightness; the range of brightness
* is -255 to 255;
* - <b>colorize</b> - adds (subtracts) specified RGB values to each pixel;
* use <b>arg1</b>, <b>arg2</b> and <b>arg3</b> in the
* form of red, green, blue and <b>arg4</b> for the alpha
* channel. the range for each color is -255 to 255 and
* 0 to 127 for alpha; <i>alpha support is available only
* for PHP 5.2.5+</i>;
* - <b>contrast</b> - changes the contrast of the image; use <b>arg1</b>
* to set the level of contrast; the range of contrast
* is -100 to 100;
* - <b>gausian_blur</b> - blurs the image using the Gaussian method;
* - <b>grayscale</b> - converts the image into grayscale;
* - <b>edgedetect</b> - uses edge detection to highlight the edges in the image;
* - <b>emboss</b> - embosses the image;
* - <b>mean_removal</b> - uses mean removal to achieve a "sketchy" effect;
* - <b>negate</b> - reverses all the colors of the image;
* - <b>pixelate</b> - applies pixelation effect to the image, use <b>arg1</b>
* to set the block size and <b>arg2</b> to set the
* pixelation effect mode; <i>this filter is available
* only for PHP 5.3.0+</i>;
* - <b>selective_blur</b> - blurs the image;
* - <b>smooth</b> - makes the image smoother. Use <b>arg1</b> to set the
* level of smoothness. applies a 9-cell convolution matrix
* where center pixel has the weight of <b>arg1</b> and
* others weight of 1.0. the result is normalized by dividing
* the sum with <b>arg1</b> + 8.0 (sum of the matrix).
* any float is accepted;
*
* @param mixed $arg1 Used by the following filters:
* - <b>brightness</b> - sets the brightness level (-255 to 255)
* - <b>contrast</b> - sets the contrast level (-100 to 100)
* - <b>colorize</b> - sets the value of the red component (-255 to 255)
* - <b>smooth</b> - sets the smoothness level
* - <b>pixelate</b> - sets the block size, in pixels
*
* @param mixed $arg2 Used by the following filters:
* - <b>colorize</b> - sets the value of the green component (-255 to 255)
* - <b>pixelate</b> - whether to use advanced pixelation effect or not (defaults to FALSE).
*
* @param mixed $arg3 Used by the following filters:
* - <b>colorize</b> - sets the value of the blue component (-255 to 255)
*
* @param mixed $arg4 Used by the following filters:
* - <b>colorize</b> - alpha channel; a value between 0 and 127. 0 indicates
* completely opaque while 127 indicates completely
* transparent.
*
* @return boolean Returns TRUE on success or FALSE on error.
*
* If {@link http://php.net/manual/en/function.imagefilter.php imagefilter} is not
* available the method will return FALSE without setting an {@link error} code.
*
* If the requested filter doesn't exist, or invalid arguments are passed, the method
* will trigger a warning.
*
* If FALSE is returned and you are sure that
* {@link http://php.net/manual/en/function.imagefilter.php imagefilter} exists and that
* the requested filter is valid, check the {@link error} property to see the error code.
* @since 2.2.2
*
*/
public function apply_filter($filter, $arg1 = '', $arg2 = '', $arg3 = '', $arg4 = '')
{
// if "imagefilter" function exists and the requested filter exists
if (function_exists('imagefilter')) // if image resource was successfully created
{
if ($this->_create_from_source()) {
// prepare the target image
$target_identifier = $this->_prepare_image($this->source_width, $this->source_height, -1);
// copy the original image
imagecopyresampled(
$target_identifier,
$this->source_identifier,
0,
0,
0,
0,
$this->source_width,
$this->source_height,
$this->source_width,
$this->source_height
);
// if multiple filters are to be applied at once
if (is_array($filter)) {
// iterate through the filters
foreach ($filter as $arguments) // if filter exists
{
if (defined('IMG_FILTER_' . strtoupper($arguments[0]))) {
// try to apply the filter...
if (!@call_user_func_array('imagefilter', array_merge([$target_identifier, constant('IMG_FILTER_' . strtoupper($arguments[0]))], array_slice($arguments, 1)))) // ...and trigger an error if the filter could not be applied
{
trigger_error('Invalid arguments used for "' . strtoupper($arguments[0]) . '" filter', E_USER_WARNING);
}
// if filter doesn't exists, trigger an error
} else {
trigger_error('Filter "' . strtoupper($arguments[0]) . '" is not available', E_USER_WARNING);
}
}
// if a single filter is to be applied and it is available
} elseif (defined('IMG_FILTER_' . strtoupper($filter))) {
// get all the arguments passed to the method
$arguments = func_get_args();
// try to apply the filter...
if (!@call_user_func_array('imagefilter', array_merge([$target_identifier, constant('IMG_FILTER_' . strtoupper($filter))], array_slice($arguments, 1)))) // ...and trigger an error if the filter could not be applied
{
trigger_error('Invalid arguments used for "' . strtoupper($arguments[0]) . '" filter', E_USER_WARNING);
}
// if filter doesn't exists, trigger an error
} else {
trigger_error('Filter "' . strtoupper($arguments[0]) . '" is not available', E_USER_WARNING);
}
// write image
return $this->_write_image($target_identifier);
}
}
// if script gets this far, return false
// note that we do not set the error level as it has been already set
// by the _create_from_source() method earlier, if the case
return false;
}
/**
* Crops a portion of the image given as {@link source_path} and outputs it as the file specified as {@link target_path}.
*
* <code>
* // include the Zebra_Image library
* require 'path/to/Zebra_Image.php';
*
* // instantiate the class
* $img = new Zebra_Image();
*
* // a source image
* $img->source_path = 'path/to/source.ext';
*
* // path to where should the resulting image be saved
* // note that by simply setting a different extension to the file will
* // instruct the script to create an image of that particular type
* $img->target_path = 'path/to/target.ext';
*
* // crop a rectangle of 100x100 pixels, starting from the top-left corner
* $img->crop(0, 0, 100, 100);
* </code>
*
* @param integer $start_x x coordinate to start cropping from
*
* @param integer $start_y y coordinate to start cropping from
*
* @param integer $end_x x coordinate where to end the cropping
*
* @param integer $end_y y coordinate where to end the cropping
*
* @return boolean Returns TRUE on success or FALSE on error.
*
* If FALSE is returned, check the {@link error} property to see the error code.
* @since 1.0.4
*
*/
public function crop($start_x, $start_y, $end_x, $end_y)
{
// this method might be also called internally
// in this case, there's a fifth argument that points to an already existing image identifier
$args = func_get_args();
// if fifth argument exists
if (isset($args[4]) && is_resource($args[4])) {
// that it is the image identifier that we'll be using further on
$this->source_identifier = $args[4];
// set this to true so that the script will continue to execute at the next IF
$result = true;
// if method is called as usually
// try to create an image resource from source path
} else {
$result = $this->_create_from_source();
}
// if image resource was successfully created
if ($result !== false) {
// compute width and height
$width = $end_x - $start_x;
$height = $end_y - $start_y;
// prepare the target image
$target_identifier = $this->_prepare_image($width, $height, -1);
// crop the image
imagecopyresampled(
$target_identifier,
$this->source_identifier,
0,
0,
$start_x,
$start_y,
$width,
$height,
$width,
$height
);
// write image
return $this->_write_image($target_identifier);
}
// if script gets this far, return false
// note that we do not set the error level as it has been already set
// by the _create_from_source() method earlier
return false;
}
/**
* Flips both horizontally and vertically the image given as {@link source_path} and outputs the resulted image as
* {@link target_path}
*
* <code>
* // include the Zebra_Image library
* require 'path/to/Zebra_Image.php';
*
* // instantiate the class
* $img = new Zebra_Image();
*
* // a source image
* $img->source_path = 'path/to/source.ext';
*
* // path to where should the resulting image be saved
* // note that by simply setting a different extension to the file will
* // instruct the script to create an image of that particular type
* $img->target_path = 'path/to/target.ext';
*
* // flip the image both horizontally and vertically
* $img->flip_both();
* </code>
*
* @return boolean Returns TRUE on success or FALSE on error.
*
* If FALSE is returned, check the {@link error} property to see the error code.
* @since 2.1
*
*/
public function flip_both()
{
return $this->_flip('both');
}
/**
* Flips horizontally the image given as {@link source_path} and outputs the resulted image as {@link target_path}
*
* <code>
* // include the Zebra_Image library
* require 'path/to/Zebra_Image.php';
*
* // instantiate the class
* $img = new Zebra_Image();
*
* // a source image
* $img->source_path = 'path/to/source.ext';
*
* // path to where should the resulting image be saved
* // note that by simply setting a different extension to the file will
* // instruct the script to create an image of that particular type
* $img->target_path = 'path/to/target.ext';
*
* // flip the image horizontally
* $img->flip_horizontal();
* </code>
*
* @return boolean Returns TRUE on success or FALSE on error.
*
* If FALSE is returned, check the {@link error} property to see the error code.
*/
public function flip_horizontal()
{
return $this->_flip('horizontal');
}
/**
* Flips vertically the image given as {@link source_path} and outputs the resulted image as {@link target_path}
*
* <code>
* // include the Zebra_Image library
* require 'path/to/Zebra_Image.php';
*
* // instantiate the class
* $img = new Zebra_Image();
*
* // a source image
* $img->source_path = 'path/to/source.ext';
*
* // path to where should the resulting image be saved
* // note that by simply setting a different extension to the file will
* // instruct the script to create an image of that particular type
* $img->target_path = 'path/to/target.ext';
*
* // flip the image vertically
* $img->flip_vertical();
* </code>
*
* @return boolean Returns TRUE on success or FALSE on error.
*
* If FALSE is returned, check the {@link error} property to see the error code.
*/
public function flip_vertical()
{
return $this->_flip('vertical');
}
/**
* Resizes the image given as {@link source_path} and outputs the resulted image as {@link target_path}.
*
* <code>
* // include the Zebra_Image library
* require 'path/to/Zebra_Image.php';
*
* // instantiate the class
* $img = new Zebra_Image();
*
* // a source image
* $img->source_path = 'path/to/source.ext';
*
* // path to where should the resulting image be saved
* // note that by simply setting a different extension to the file will
* // instruct the script to create an image of that particular type
* $img->target_path = 'path/to/target.ext';
*
* // apply a "sharpen" filter to the resulting images
* $img->sharpen_images = true;
*
* // resize the image to exactly 150x150 pixels, without altering
* // aspect ratio, by using the CROP_CENTER method
* $img->resize(150, 150, ZEBRA_IMAGE_CROP_CENTER);
* </code>
*
* @param integer $width The width to resize the image to.
*
* If set to <b>0</b>, the width will be automatically adjusted, depending
* on the value of the <b>height</b> argument so that the image preserves
* its aspect ratio.
*
* If {@link preserve_aspect_ratio} is set to TRUE and both this and the
* <b>height</b> arguments are values greater than <b>0</b>, the image will
* be resized to the exact required width and height and the aspect ratio
* will be preserved - (also see the description for the <b>method</b>
* argument below on how can this be done).
*
* If {@link preserve_aspect_ratio} is set to FALSE, the image will be
* resized to the required width and the aspect ratio will be ignored.
*
* If both <b>width</b> and <b>height</b> are set to <b>0</b>, a copy of
* the source image will be created ({@link jpeg_quality} and
* {@link png_compression} will still apply).
*
* If either <b>width</b> or <b>height</b> are set to <b>0</b>, the script
* will consider the value of the {@link preserve_aspect_ratio} to bet set
* to TRUE regardless of its actual value!
*
* @param integer $height The height to resize the image to.
*
* If set to <b>0</b>, the height will be automatically adjusted, depending
* on the value of the <b>width</b> argument so that the image preserves
* its aspect ratio.
*
* If {@link preserve_aspect_ratio} is set to TRUE and both this and the
* <b>width</b> arguments are values greater than <b>0</b>, the image will
* be resized to the exact required width and height and the aspect ratio
* will be preserved - (also see the description for the <b>method</b>
* argument below on how can this be done).
*
* If {@link preserve_aspect_ratio} is set to FALSE, the image will be
* resized to the required height and the aspect ratio will be ignored.
*
* If both <b>width</b> and <b>height</b> are set to <b>0</b>, a copy of
* the source image will be created ({@link jpeg_quality} and
* {@link png_compression} will still apply).
*
* If either <b>height</b> or <b>width</b> are set to <b>0</b>, the script
* will consider the value of the {@link preserve_aspect_ratio} to bet set
* to TRUE regardless of its actual value!
*
* @param int $method (Optional) Method to use when resizing images to exact width and height
* while preserving aspect ratio.
*
* If the {@link preserve_aspect_ratio} property is set to TRUE and both the
* <b>width</b> and <b>height</b> arguments are values greater than <b>0</b>,
* the image will be resized to the exact given width and height and the
* aspect ratio will be preserved by using on of the following methods:
*
* - <b>ZEBRA_IMAGE_BOXED</b> - the image will be scaled so that it will
* fit in a box with the given width and height (both width/height will
* be smaller or equal to the required width/height) and then it will
* be centered both horizontally and vertically. The blank area will be
* filled with the color specified by the <b>bgcolor</b> argument. (the
* blank area will be filled only if the image is not transparent!)
*
* - <b>ZEBRA_IMAGE_NOT_BOXED</b> - the image will be scaled so that it
* <i>could</i> fit in a box with the given width and height but will
* not be enclosed in a box with given width and height. The new width/
* height will be both smaller or equal to the required width/height
*
* - <b>ZEBRA_IMAGE_CROP_TOPLEFT</b>
* - <b>ZEBRA_IMAGE_CROP_TOPCENTER</b>
* - <b>ZEBRA_IMAGE_CROP_TOPRIGHT</b>
* - <b>ZEBRA_IMAGE_CROP_MIDDLELEFT</b>
* - <b>ZEBRA_IMAGE_CROP_CENTER</b>
* - <b>ZEBRA_IMAGE_CROP_MIDDLERIGHT</b>
* - <b>ZEBRA_IMAGE_CROP_BOTTOMLEFT</b>
* - <b>ZEBRA_IMAGE_CROP_BOTTOMCENTER</b>
* - <b>ZEBRA_IMAGE_CROP_BOTTOMRIGHT</b>
*
* For the methods involving crop, first the image is scaled so that both
* its sides are equal or greater than the respective sizes of the bounding
* box; next, a region of required width and height will be cropped from
* indicated region of the resulted image.
*
* Default is ZEBRA_IMAGE_CROP_CENTER
*
* @param hexadecimal $background_color (Optional) The hexadecimal color (like "#FFFFFF" or "#FFF") of the
* blank area. See the <b>method</b> argument.
*
* When set to -1 the script will preserve transparency for transparent GIF
* and PNG images. For non-transparent images the background will be white
* (#FFFFFF) in this case.
*
* Default is -1
*
* @return boolean Returns TRUE on success or FALSE on error.
*
* If FALSE is returned, check the {@link error} property to see what went
* wrong
*/
public function resize($width = 0, $height = 0, $method = ZEBRA_IMAGE_CROP_CENTER, $background_color = -1)
{
// if image resource was successfully created
if ($this->_create_from_source()) {
// if either width or height is to be adjusted automatically
// set a flag telling the script that, even if $preserve_aspect_ratio is set to false
// treat everything as if it was set to true
if ($width == 0 || $height == 0) {
$auto_preserve_aspect_ratio = true;
}
// if aspect ratio needs to be preserved
if ($this->preserve_aspect_ratio || isset($auto_preserve_aspect_ratio)) {
// if height is given and width is to be computed accordingly
if ($width == 0 && $height > 0) {
// get the original image's aspect ratio
$aspect_ratio = $this->source_width / $this->source_height;
// the target image's height is as given as argument to the method
$target_height = $height;
// compute the target image's width, preserving the aspect ratio
$target_width = round($height * $aspect_ratio);
// if width is given and height is to be computed accordingly
} elseif ($width > 0 && $height == 0) {
// get the original image's aspect ratio
$aspect_ratio = $this->source_height / $this->source_width;
// the target image's width is as given as argument to the method
$target_width = $width;
// compute the target image's height, preserving the aspect ratio
$target_height = round($width * $aspect_ratio);
// if both width and height are given and ZEBRA_IMAGE_BOXED or ZEBRA_IMAGE_NOT_BOXED methods are to be used
} elseif ($width > 0 && $height > 0 && ($method == 0 || $method == 1)) {
// compute the horizontal and vertical aspect ratios
$vertical_aspect_ratio = $height / $this->source_height;
$horizontal_aspect_ratio = $width / $this->source_width;
// if the image's newly computed height would be inside the bounding box
if (round($horizontal_aspect_ratio * $this->source_height < $height)) {
// the target image's width is as given as argument to the method
$target_width = $width;
// compute the target image's height so that the image will stay inside the bounding box
$target_height = round($horizontal_aspect_ratio * $this->source_height);
// otherwise
} else {
// the target image's height is as given as argument to the method
$target_height = $height;
// compute the target image's width so that the image will stay inside the bounding box
$target_width = round($vertical_aspect_ratio * $this->source_width);
}
// if both width and height are given and image is to be cropped in order to get to the required size
} elseif ($width > 0 && $height > 0 && $method > 1 && $method < 11) {
// compute the horizontal and vertical aspect ratios
$vertical_aspect_ratio = $this->source_height / $height;
$horizontal_aspect_ratio = $this->source_width / $width;
// we'll use one of the two
$aspect_ratio =
$vertical_aspect_ratio < $horizontal_aspect_ratio ?
$vertical_aspect_ratio :
$horizontal_aspect_ratio;
// compute the target image's width, preserving the aspect ratio
$target_width = round($this->source_width / $aspect_ratio);
// compute the target image's height, preserving the aspect ratio
$target_height = round($this->source_height / $aspect_ratio);
// for any other case
} else {
// we will create a copy of the source image
$target_width = $this->source_width;
$target_height = $this->source_height;
}
// if aspect ratio does not need to be preserved
} else {
// compute the target image's width
$target_width = ($width > 0 ? $width : $this->source_width);
// compute the target image's height
$target_height = ($height > 0 ? $height : $this->source_height);
}
// if
if (
// all images are to be resized - including images that are smaller than the given width/height
$this->enlarge_smaller_images
|| // smaller images than the given width/height are to be left untouched
// but current image has at leas one side that is larger than the required width/height
($width > 0 && $height > 0 ?
($this->source_width > $width || $this->source_height > $height) :
($this->source_width > $target_width || $this->source_height > $target_height)
)
) {
// if
if (
// aspect ratio needs to be preserved AND
($this->preserve_aspect_ratio || isset($auto_preserve_aspect_ratio))
&& // both width and height are given
($width > 0 && $height > 0)
&& // images are to be cropped
($method > 1 && $method < 11)
) {
// prepare the target image
$target_identifier = $this->_prepare_image($target_width, $target_height, $background_color);
imagecopyresampled(
$target_identifier,
$this->source_identifier,
0,
0,
0,
0,
$target_width,
$target_height,
$this->source_width,
$this->source_height
);
// do the crop according to the required method
switch ($method) {
// if image needs to be cropped from the top-left corner
case ZEBRA_IMAGE_CROP_TOPLEFT:
// crop accordingly
return $this->crop(
0,
0,
$width,
$height,
$target_identifier // crop this resource instead
);
break;
// if image needs to be cropped from the top-center
case ZEBRA_IMAGE_CROP_TOPCENTER:
// crop accordingly
return $this->crop(
floor(($target_width - $width) / 2),
0,
floor(($target_width - $width) / 2) + $width,
$height,
$target_identifier // crop this resource instead
);
break;
// if image needs to be cropped from the top-right corner
case ZEBRA_IMAGE_CROP_TOPRIGHT:
// crop accordingly
return $this->crop(
$target_width - $width,
0,
$target_width,
$height,
$target_identifier // crop this resource instead
);
break;
// if image needs to be cropped from the middle-left
case ZEBRA_IMAGE_CROP_MIDDLELEFT:
// crop accordingly
return $this->crop(
0,
floor(($target_height - $height) / 2),
$width,
floor(($target_height - $height) / 2) + $height,
$target_identifier // crop this resource instead
);
break;
// if image needs to be cropped from the center of the image
case ZEBRA_IMAGE_CROP_CENTER:
// crop accordingly
return $this->crop(
floor(($target_width - $width) / 2),
floor(($target_height - $height) / 2),
floor(($target_width - $width) / 2) + $width,
floor(($target_height - $height) / 2) + $height,
$target_identifier // crop this resource instead
);
break;
// if image needs to be cropped from the middle-right
case ZEBRA_IMAGE_CROP_MIDDLERIGHT:
// crop accordingly
return $this->crop(
$target_width - $width,
floor(($target_height - $height) / 2),
$target_width,
floor(($target_height - $height) / 2) + $height,
$target_identifier // crop this resource instead
);
break;
// if image needs to be cropped from the bottom-left corner
case ZEBRA_IMAGE_CROP_BOTTOMLEFT:
// crop accordingly
return $this->crop(
0,
$target_height - $height,
$width,
$target_height,
$target_identifier // crop this resource instead
);
break;
// if image needs to be cropped from the bottom-center
case ZEBRA_IMAGE_CROP_BOTTOMCENTER:
// crop accordingly
return $this->crop(
floor(($target_width - $width) / 2),
$target_height - $height,
floor(($target_width - $width) / 2) + $width,
$target_height,
$target_identifier // crop this resource instead
);
break;
// if image needs to be cropped from the bottom-right corner
case ZEBRA_IMAGE_CROP_BOTTOMRIGHT:
// crop accordingly
return $this->crop(
$target_width - $width,
$target_height - $height,
$target_width,
$target_height,
$target_identifier // crop this resource instead
);
break;
}
// if aspect ratio doesn't need to be preserved or
// it needs to be preserved and method is ZEBRA_IMAGE_BOXED or ZEBRA_IMAGE_NOT_BOXED
} else {
// prepare the target image
$target_identifier = $this->_prepare_image(
($width > 0 && $height > 0 && $method != ZEBRA_IMAGE_NOT_BOXED ? $width : $target_width),
($width > 0 && $height > 0 && $method != ZEBRA_IMAGE_NOT_BOXED ? $height : $target_height),
$background_color
);
imagecopyresampled(
$target_identifier,
$this->source_identifier,
($width > 0 && $height > 0 && $method != ZEBRA_IMAGE_NOT_BOXED ? ($width - $target_width) / 2 : 0),
($width > 0 && $height > 0 && $method != ZEBRA_IMAGE_NOT_BOXED ? ($height - $target_height) / 2 : 0),
0,
0,
$target_width,
$target_height,
$this->source_width,
$this->source_height
);
// if script gets this far, write the image to disk
return $this->_write_image($target_identifier);
}
// if we get here it means that
// smaller images than the given width/height are to be left untouched
// therefore, we save the image as it is
} else {
// prepare the target image
$target_identifier = $this->_prepare_image($this->source_width, $this->source_height, $background_color);
imagecopyresampled(
$target_identifier,
$this->source_identifier,
0,
0,
0,
0,
$this->source_width,
$this->source_height,
$this->source_width,
$this->source_height
);
// previously to 2.2.7 I was simply calling the _write_images() method without the code from above this
// comment and therefore, when resizing transparent images to a format which doesn't support transparency
// and the "enlarge_smaller_images" property being set to FALSE, the "background_color" argument was not
// applied and lead to unexpected background colors for the resulting images
return $this->_write_image($target_identifier);
}
}
// if script gets this far return false
// note that we do not set the error level as it has been already set
// by the _create_from_source() method earlier
return false;
}
/**
* Rotates the image given as {@link source_path} and outputs the resulted image as {@link target_path}.
*
* <code>
* // include the Zebra_Image library
* require 'path/to/Zebra_Image.php';
*
* // instantiate the class
* $img = new Zebra_Image();
*
* // a source image
* $img->source_path = 'path/to/source.ext';
*
* // path to where should the resulting image be saved
* // note that by simply setting a different extension to the file will
* // instruct the script to create an image of that particular type
* $img->target_path = 'path/to/target.ext';
*
* // rotate the image 45 degrees, clockwise
* $img->rotate(45);
* </code>
*
* @param double $angle Angle by which to rotate the image clockwise.
*
* Between 0 and 360.
*
* @param mixed $background_color (Optional) The hexadecimal color (like "#FFFFFF" or "#FFF") of the
* uncovered zone after the rotation.
*
* When set to -1 the script will preserve transparency for transparent GIF
* and PNG images. For non-transparent images the background will be white
* (#FFFFFF) in this case.
*
* Default is -1.
*
* @return boolean Returns TRUE on success or FALSE on error.
*
* If FALSE is returned, check the {@link error} property to see the error
* code.
*/
public function rotate($angle, $background_color = -1)
{
// get function arguments
$arguments = func_get_args();
// if a third argument exists
$use_existing_source = (isset($arguments[2]) && $arguments[2] === false);
// if we came here just to fix orientation or if image resource was successfully created
if ($use_existing_source || $this->_create_from_source()) {
// angles are given clockwise but imagerotate works counterclockwise so we need to negate our value
$angle = -$angle;
// if the uncovered zone after the rotation is to be transparent
if ($background_color == -1) {
// if target image is a PNG
if ($this->target_type == 'png') {
// allocate a transparent color
$background_color = imagecolorallocatealpha($this->source_identifier, 0, 0, 0, 127);
// if target image is a GIF
} elseif ($this->target_type == 'gif') {
// if source image was a GIF and a transparent color existed
if ($this->source_type == IMAGETYPE_GIF && $this->source_transparent_color_index >= 0) {
// use that color
$background_color = imagecolorallocate(
$this->source_identifier,
$this->source_transparent_color['red'],
$this->source_transparent_color['green'],
$this->source_transparent_color['blue']
);
// if image had no transparent color
} else {
// allocate a transparent color
$background_color = imagecolorallocate($this->source_identifier, 255, 255, 255);
// make color transparent
imagecolortransparent($this->source_identifier, $background_color);
}
// for other image types
} else {
// use white as the color of uncovered zone after the rotation
$background_color = imagecolorallocate($this->source_identifier, 255, 255, 255);
}
// if a background color is given
} else {
// convert the color to RGB values
$background_color = $this->_hex2rgb($background_color);
// allocate the color to the image identifier
$background_color = imagecolorallocate(
$this->source_identifier,
$background_color['r'],
$background_color['g'],
$background_color['b']
);
}
// rotate the image
$target_identifier = imagerotate($this->source_identifier, $angle, $background_color);
// if we called this method from the _create_from_source() method
// because we are fixing orientation
if ($use_existing_source) {
// make any further method work on the rotated image
$this->source_identifier = $target_identifier;
// update the width and height of the image to the values
// of the rotated image
$this->source_width = imagesx($target_identifier);
$this->source_height = imagesy($target_identifier);
return true;
// write image otherwise
} else {
return $this->_write_image($target_identifier);
}
}
// if script gets this far return false
// note that we do not set the error level as it has been already set
// by the _create_from_source() method earlier
return false;
}
/**
* Returns an array containing the image identifier representing the image obtained from {@link $source_path}, the
* image's width and height and the image's type
*
* @access private
*/
private function _create_from_source()
{
// perform some error checking first
// if the GD library is not installed
if (!function_exists('gd_info')) {
// save the error level and stop the execution of the script
$this->error = 7;
return false;
// if source file does not exist
} elseif (!is_file($this->source_path)) {
// save the error level and stop the execution of the script
$this->error = 1;
return false;
// if source file is not readable
} elseif (!is_readable($this->source_path)) {
// save the error level and stop the execution of the script
$this->error = 2;
return false;
// if target file is same as source file and source file is not writable
} elseif ($this->target_path == $this->source_path && !is_writable($this->source_path)) {
// save the error level and stop the execution of the script
$this->error = 3;
return false;
// try to get source file width, height and type
// and if it founds an unsupported file type
} elseif (!list($this->source_width, $this->source_height, $this->source_type) = @getimagesize($this->source_path)) {
// save the error level and stop the execution of the script
$this->error = 4;
return false;
// if no errors so far
} else {
// get target file's type based on the file extension
$this->target_type = strtolower(substr($this->target_path, strrpos($this->target_path, '.') + 1));
// create an image from file using extension dependant function
// checks for file extension
switch ($this->source_type) {
// if GIF
case IMAGETYPE_GIF:
// create an image from file
$identifier = imagecreatefromgif($this->source_path);
// get the index of the transparent color (if any)
if (($this->source_transparent_color_index = imagecolortransparent($identifier)) >= 0)
// get the transparent color's RGB values
// we have to mute errors because there are GIF images which *are* transparent and everything
// works as expected, but imagecolortransparent() returns a color that is outside the range of
// colors in the image's pallette...
{
$this->source_transparent_color = @imagecolorsforindex($identifier, $this->source_transparent_color_index);
}
break;
// if JPEG
case IMAGETYPE_JPEG:
// create an image from file
$identifier = imagecreatefromjpeg($this->source_path);
break;
// if PNG
case IMAGETYPE_PNG:
// create an image from file
$identifier = imagecreatefrompng($this->source_path);
// disable blending
imagealphablending($identifier, false);
// save full alpha channel information
imagesavealpha($identifier, true);
break;
default:
// if unsupported file type
// note that we call this if the file is not GIF, JPG or PNG even though the getimagesize function
// handles more image types
$this->error = 4;
return false;
}
}
// if target file has to have the same timestamp as the source image
// save it as a global property of the class
if ($this->preserve_time) {
$this->source_image_time = filemtime($this->source_path);
}
// make available the source image's identifier
$this->source_identifier = $identifier;
// for JPEG files, if we need to handle exif orientation automatically
if ($this->auto_handle_exif_orientation && $this->source_type === IMAGETYPE_JPEG) // if "exif_read_data" function is not available, return false
{
if (!function_exists('exif_read_data')) {
// save the error level and stop the execution of the script
$this->error = 9;
return false;
// if "exif_read_data" function is available, EXIF information is available, orientation information is available and orientation needs fixing
} elseif (($exif = exif_read_data($this->source_path)) && isset($exif['Orientation']) && in_array($exif['Orientation'], [3, 6, 8])) {
// fix the orientation
switch ($exif['Orientation']) {
case 3:
// 180 rotate left
$this->rotate(180, -1, false);
break;
case 6:
// 90 rotate right
$this->rotate(90, -1, false);
break;
case 8:
// 90 rotate left
$this->rotate(-90, -1, false);
break;
}
}
}
return true;
}
/**
* Flips horizontally or vertically or both ways the image given as {@link source_path}.
*
* @return boolean Returns TRUE on success or FALSE on error.
*
* If FALSE is returned, check the {@link error} property to see the error code.
* @since 2.1
*
* @access private
*
*/
private function _flip($orientation)
{
// if image resource was successfully created
if ($this->_create_from_source()) {
// prepare the target image
$target_identifier = $this->_prepare_image($this->source_width, $this->source_height, -1);
// flip according to $orientation
switch ($orientation) {
case 'horizontal':
imagecopyresampled(
$target_identifier,
$this->source_identifier,
0,
0,
($this->source_width - 1),
0,
$this->source_width,
$this->source_height,
-$this->source_width,
$this->source_height
);
break;
case 'vertical':
imagecopyresampled(
$target_identifier,
$this->source_identifier,
0,
0,
0,
($this->source_height - 1),
$this->source_width,
$this->source_height,
$this->source_width,
-$this->source_height
);
break;
case 'both':
imagecopyresampled(
$target_identifier,
$this->source_identifier,
0,
0,
($this->source_width - 1),
($this->source_height - 1),
$this->source_width,
$this->source_height,
-$this->source_width,
-$this->source_height
);
break;
}
// write image
return $this->_write_image($target_identifier);
}
// if script gets this far, return false
// note that we do not set the error level as it has been already set
// by the _create_from_source() method earlier
return false;
}
/**
* Converts a hexadecimal representation of a color (i.e. #123456 or #AAA) to a RGB representation.
*
* The RGB values will be a value between 0 and 255 each.
*
* @param string $color Hexadecimal representation of a color (i.e. #123456 or #AAA).
*
* @param string $default_on_error (Optional) Hexadecimal representation of a color to be used in case $color
* is not recognized as a hexadecimal color.
*
* Default is #FFFFFF
*
* @return array Returns an associative array with the values of (R)ed, (G)reen and (B)lue
*
* @access private
*/
private function _hex2rgb($color, $default_on_error = '#FFFFFF')
{
// if color is not formatted correctly
// use the default color
if (preg_match('/^#?([a-f]|[0-9]){3}(([a-f]|[0-9]){3})?$/i', $color) == 0) {
$color = $default_on_error;
}
// trim off the "#" prefix from $background_color
$color = ltrim($color, '#');
// if color is given using the shorthand (i.e. "FFF" instead of "FFFFFF")
if (strlen($color) == 3) {
$tmp = '';
// take each value
// and duplicate it
for ($i = 0; $i < 3; $i++) {
$tmp .= str_repeat($color[$i], 2);
}
// the color in it's full, 6 characters length notation
$color = $tmp;
}
// decimal representation of the color
$int = hexdec($color);
// extract and return the RGB values
return [
'r' => 0xFF & ($int >> 0x10),
'g' => 0xFF & ($int >> 0x8),
'b' => 0xFF & $int,
];
}
/**
* Creates a blank image of given width, height and background color.
*
* @param integer $width Width of the new image.
*
* @param integer $height Height of the new image.
*
* @param string $background_color (Optional) The hexadecimal color of the background.
*
* Can also be -1 case in which the script will try to create a transparent
* image, if possible.
*
* Default is #FFFFFF.
*
* @return Returns the identifier of the newly created image.
*
* @access private
*/
private function _prepare_image($width, $height, $background_color = '#FFFFFF')
{
// create a blank image
$identifier = imagecreatetruecolor((int)$width <= 0 ? 1 : (int)$width, (int)$height <= 0 ? 1 : (int)$height);
// if we are creating a transparent image, and image type supports transparency
if ($background_color == -1 && $this->target_type != 'jpg') {
// disable blending
imagealphablending($identifier, false);
// allocate a transparent color
$background_color = imagecolorallocatealpha($identifier, 0, 0, 0, 127);
// we also need to set this for saving gifs
imagecolortransparent($identifier, $background_color);
// save full alpha channel information
imagesavealpha($identifier, true);
// if we are not creating a transparent image
} else {
// convert hex color to rgb
$background_color = $this->_hex2rgb($background_color);
// prepare the background color
$background_color = imagecolorallocate($identifier, $background_color['r'], $background_color['g'], $background_color['b']);
}
// fill the image with the background color
imagefill($identifier, 0, 0, $background_color);
// return the image's identifier
return $identifier;
}
/**
* Sharpens images. Useful when creating thumbnails.
*
* Code taken from the comments at {@link http://docs.php.net/imageconvolution}.
*
* <i>This function will yield a result only for PHP version 5.1.0+ and will leave the image unaltered for older
* versions!</i>
*
* @param $identifier identifier An image identifier
*
* @access private
*/
private function _sharpen_image($image)
{
// if the "sharpen_images" is set to true and we're running an appropriate version of PHP
// (the "imageconvolution" is available only for PHP 5.1.0+)
if ($this->sharpen_images && version_compare(PHP_VERSION, '5.1.0') >= 0) {
// the convolution matrix as an array of three arrays of three floats
$matrix = [
[-1.2, -1, -1.2],
[-1, 20, -1],
[-1.2, -1, -1.2],
];
// the divisor of the matrix
$divisor = array_sum(array_map('array_sum', $matrix));
// color offset
$offset = 0;
// sharpen image
imageconvolution($image, $matrix, $divisor, $offset);
}
// return the image's identifier
return $image;
}
/**
* Creates a new image from given image identifier having the extension as specified by {@link target_path}.
*
* @param $identifier identifier An image identifier
*
* @return boolean Returns TRUE on success or FALSE on error.
*
* If FALSE is returned, check the {@link error} property to see the error code.
*
* @access private
*/
private function _write_image($identifier)
{
// sharpen image if it's required
$this->_sharpen_image($identifier);
// image saving process goes according to required extension
switch ($this->target_type) {
// if GIF
case 'gif':
// if GD support for this file type is not available
// in version 1.6 of GD the support for GIF files was dropped see
// http://php.net/manual/en/function.imagegif.php#function.imagegif.notes
if (!function_exists('imagegif')) {
// save the error level and stop the execution of the script
$this->error = 6;
return false;
// if, for some reason, file could not be created
} elseif (@!imagegif($identifier, $this->target_path)) {
// save the error level and stop the execution of the script
$this->error = 3;
return false;
}
break;
// if JPEG
case 'jpg':
case 'jpeg':
// if GD support for this file type is not available
if (!function_exists('imagejpeg')) {
// save the error level and stop the execution of the script
$this->error = 6;
return false;
// if, for some reason, file could not be created
} elseif (@!imagejpeg($identifier, $this->target_path, $this->jpeg_quality)) {
// save the error level and stop the execution of the script
$this->error = 3;
return false;
}
break;
// if PNG
case 'png':
// if GD support for this file type is not available
if (!function_exists('imagepng')) {
// save the error level and stop the execution of the script
$this->error = 6;
return false;
// if, for some reason, file could not be created
} elseif (@!imagepng($identifier, $this->target_path, $this->png_compression)) {
// save the error level and stop the execution of the script
$this->error = 3;
return false;
}
break;
// if not a supported file extension
default:
// save the error level and stop the execution of the script
$this->error = 5;
return false;
}
// get a list of functions disabled via configuration
$disabled_functions = @ini_get('disable_functions');
// if the 'chmod' function is not disabled via configuration
if ($disabled_functions == '' || strpos('chmod', $disabled_functions) === false) {
// chmod the file
chmod($this->target_path, intval($this->chmod_value, 8));
// save the error level
} else {
$this->error = 8;
}
// if target file has to have the same timestamp as the source image
if ($this->preserve_time && isset($this->source_image_time)) {
// touch the newly created file
@touch($this->target_path, $this->source_image_time);
}
// free memory
imagedestroy($this->source_identifier);
imagedestroy($identifier);
// return true
return true;
}
}