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Diffstat (limited to 'application/libraries/Image.php')
| -rw-r--r-- | application/libraries/Image.php | 267 |
1 files changed, 267 insertions, 0 deletions
diff --git a/application/libraries/Image.php b/application/libraries/Image.php new file mode 100644 index 000000000..6d6c9e563 --- /dev/null +++ b/application/libraries/Image.php @@ -0,0 +1,267 @@ +<?php +/* + * Copyright 2014 Florian "Bluewind" Pritz <bluewind@server-speed.net> + * + * Licensed under AGPLv3 + * (see COPYING for full license text) + * + */ + +namespace libraries; + +/** + * This class deals with a single image and provides useful operations that + * operate on this image. + */ +class Image { + private $img; + private $source_type; + private $exif; + + /** + * Create a new object and load the contents of file. + * @param file file to read + */ + public function __construct($file) + { + $this->read($file); + } + + /** + * Replace the current image by reading in a file + * @param file file to read + */ + public function read($file) + { + $img = imagecreatefromstring(file_get_contents($file)); + if ($img === false) { + show_error("Unsupported image type"); + } + $this->set_img_object($img); + $this->fix_alpha(); + + $this->source_type = getimagesize($file)[2]; + + switch ($this->source_type) { + case IMAGETYPE_JPEG: + $this->exif = exif_read_data($file); + break; + default: + } + } + + /** + * Return the current image rendered to a specific format. Passing null as + * the target_type returns the image in the format of the source image + * (loaded with read()). + * + * @param target_type one of IMAGETYPE_GIF, IMAGETYPE_JPEG, IMAGETYPE_PNG or null + * @return binary image data + */ + public function get($target_type = null) + { + if ($target_type === null) { + $target_type = $this->source_type; + } + + ob_start(); + switch ($target_type) { + case IMAGETYPE_GIF: + $ret = imagegif($this->img); + break; + case IMAGETYPE_JPEG: + $ret = imagejpeg($this->img); + break; + case IMAGETYPE_PNG: + $ret = imagepng($this->img); + break; + default: + assert(0); + } + $result = ob_get_clean(); + + if (!$ret) { + show_error("Failed to create thumbnail"); + } + + return $result; + } + + /** + * Resize the image. + * @param width + * @param height + */ + public function resize($width, $height) + { + $temp_gdim = imagecreatetruecolor($width, $height); + $this->fix_alpha(); + imagecopyresampled( + $temp_gdim, + $this->img, + 0, 0, + 0, 0, + $width, $height, + imagesx($this->img), imagesy($this->img) + ); + + $this->set_img_object($temp_gdim); + } + + /** + * Crop the image to the area defined by x, y, width and height. + * + * @param x starting coordinate + * @param y starting coordinate + * @param width width of the area + * @param height height of the area + */ + public function crop($x, $y, $width, $height) + { + $thumb = imagecreatetruecolor($width, $height); + $this->fix_alpha(); + imagecopy( + $thumb, + $this->img, + 0, 0, + $x, $y, + $width, $height + ); + + $this->set_img_object($thumb); + } + + /** + * Crop/resize the image to fit into the desired size. This also rotates + * the image if the source image had an EXIF orientation tag. + * + * @param width width of the resulting image + * @param height height of the resulting image + */ + // Source: http://salman-w.blogspot.co.at/2009/04/crop-to-fit-image-using-aspphp.html + public function makeThumb($target_width, $target_height) + { + $source_aspect_ratio = imagesx($this->img) / imagesy($this->img); + $desired_aspect_ratio = $target_width / $target_height; + + if ($source_aspect_ratio > $desired_aspect_ratio) { + // Triggered when source image is wider + $temp_height = $target_height; + $temp_width = round(($target_height * $source_aspect_ratio)); + } else { + // Triggered otherwise (i.e. source image is similar or taller) + $temp_width = $target_width; + $temp_height = round(($target_width / $source_aspect_ratio)); + } + + $this->resize($temp_width, $temp_height); + + $x0 = ($temp_width - $target_width) / 2; + $y0 = ($temp_height - $target_height) / 2; + $this->crop($x0, $y0, $target_width, $target_height); + + $this->apply_exif_orientation(); + } + + static public function get_exif_orientation($file) + { + $type = getimagesize($file)[2]; + switch ($type) { + case IMAGETYPE_JPEG: + $exif = exif_read_data($file); + if (isset($exif["Orientation"])) { + return $exif["Orientation"]; + } + return 0; + break; + default: + return 0; + } + } + + /** + * Rotate the image according to the sources EXIF orientation tag if any. + */ + public function apply_exif_orientation() + { + if (isset($this->exif['Orientation'])) { + $mirror = false; + $deg = 0; + + switch ($this->exif['Orientation']) { + case 2: + $mirror = true; + break; + case 3: + $deg = 180; + break; + case 4: + $deg = 180; + $mirror = true; + break; + case 5: + $deg = 270; + $mirror = true; + break; + case 6: + $deg = 270; + break; + case 7: + $deg = 90; + $mirror = true; + break; + case 8: + $deg = 90; + break; + } + + if ($deg) { + $this->set_img_object(imagerotate($this->img, $deg, 0)); + } + + if ($mirror) { + $this->mirror(); + } + } + } + + /** + * Mirror the image along the x axis. + */ + public function mirror() + { + $width = imagesx($this->img); + $height = imagesy($this->img); + + $src_x = $width -1; + $src_y = 0; + $src_width = -$width; + $src_height = $height; + + $imgdest = imagecreatetruecolor($width, $height); + imagealphablending($imgdest,false); + imagesavealpha($imgdest,true); + + imagecopyresampled($imgdest, $this->img, 0, 0, $src_x, $src_y, $width, $height, $src_width, $src_height); + $this->set_img_object($imgdest); + } + + private function set_img_object($new) + { + assert($new !== false); + + $old = $this->img; + $this->img = $new; + + if ($old != null) { + imagedestroy($old); + } + } + + private function fix_alpha() + { + imagealphablending($this->img,false); + imagesavealpha($this->img,true); + } + +} |