diff options
Diffstat (limited to 'application/libraries')
| -rw-r--r-- | application/libraries/Imglib.php | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/application/libraries/Imglib.php b/application/libraries/Imglib.php new file mode 100644 index 000000000..4d6de21d3 --- /dev/null +++ b/application/libraries/Imglib.php @@ -0,0 +1,169 @@ +<?php +/* + * Copyright 2014 Florian "Bluewind" Pritz <bluewind@server-speed.net> + * + * Licensed under AGPLv3 + * (see COPYING for full license text) + * + */ + +class Imglib { + /* + * This returns a square thumbnail for the input image + * Source: http://salman-w.blogspot.co.at/2009/04/crop-to-fit-image-using-aspphp.html + */ + public function makeThumb($file, $size = 150, $target_type = null) + { + $source_gdim = imagecreatefromstring(file_get_contents($file)); + if ($source_gdim === false) { + show_error("Unsupported image type"); + } + imagealphablending($source_gdim,false); + imagesavealpha($source_gdim,true); + + list($source_width, $source_height, $source_type) = getimagesize($file); + + if ($target_type === null) { + $target_type = $source_type; + } + + $target_width = $size; + $target_height = $size; + + $source_aspect_ratio = $source_width / $source_height; + $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)); + } + + /* + * Resize the image into a temporary GD image + */ + + $temp_gdim = imagecreatetruecolor($temp_width, $temp_height); + imagealphablending($temp_gdim,false); + imagesavealpha($temp_gdim,true); + imagecopyresampled( + $temp_gdim, + $source_gdim, + 0, 0, + 0, 0, + $temp_width, $temp_height, + $source_width, $source_height + ); + + /* + * Copy cropped region from temporary image into the desired GD image + */ + + $x0 = ($temp_width - $target_width) / 2; + $y0 = ($temp_height - $target_height) / 2; + $thumb = imagecreatetruecolor($target_width, $target_height); + imagealphablending($thumb,false); + imagesavealpha($thumb,true); + imagecopy( + $thumb, + $temp_gdim, + 0, 0, + $x0, $y0, + $target_width, $target_height + ); + + /* + * Fix orientation according to exif tag + */ + try { + $exif = exif_read_data($file); + } catch (ErrorException $e) { + } + + if (isset($exif['Orientation'])) { + $mirror = false; + $deg = 0; + + switch ($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) $thumb = imagerotate($thumb, $deg, 0); + if ($mirror) $thumb = $this->_mirrorImage($thumb); + } + + ob_start(); + switch ($target_type) { + case IMAGETYPE_GIF: + $ret = imagegif($thumb); + break; + case IMAGETYPE_JPEG: + $ret = imagejpeg($thumb); + break; + case IMAGETYPE_PNG: + $ret = imagepng($thumb); + break; + default: + assert(0); + } + $result = ob_get_clean(); + + if (!$ret) { + show_error("Failed to create thumbnail"); + } + + imagedestroy($thumb); + imagedestroy($temp_gdim); + imagedestroy($source_gdim); + + return $result; + } + + private function _mirrorImage($imgsrc) + { + $width = imagesx($imgsrc); + $height = imagesy($imgsrc); + + $src_x = $width -1; + $src_y = 0; + $src_width = -$width; + $src_height = $height; + + $imgdest = imagecreatetruecolor($width, $height); + imagealphablending($imgdest,false); + imagesavealpha($imgdest,true); + + if (imagecopyresampled($imgdest, $imgsrc, 0, 0, $src_x, $src_y, $width, $height, $src_width, $src_height)) { + return $imgdest; + } + + return $imgsrc; + } + +} |