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Creating Thumbnails on Image Upload
When users upload images, it's common practice to create thumbnails alongside the original image. This allows for faster loading of smaller images while maintaining a higher-quality version for display when necessary.
Database Structure
In this case, the database has two columns to store images: user_pic for the original image and user_pic_small for the thumbnail.
Image Upload Form
The image upload form, imageupload.php, handles the file upload and inserts the full-size image into the database.
Image Processing PHP Script
The PHP script, media.profileimage.upload.php, checks if an image was uploaded and creates a thumbnail if needed.
ImageMagick (Optional)
ImageMagick can be used to generate thumbnails more efficiently. Here's an example using Imagick:
/** * @param string $img Image path * @param int $width * @param int $height * @param int $quality * @return bool * @throws Exception */ function generateThumbnail($img, $width, $height, $quality = 90) { $imagick = new Imagick(realpath($img)); $imagick->setImageFormat('jpeg'); $imagick->setImageCompression(Imagick::COMPRESSION_JPEG); $imagick->setImageCompressionQuality($quality); $imagick->thumbnailImage($width, $height, false, false); $filename_no_ext = reset(explode('.', $img)); return file_put_contents($filename_no_ext . '_thumb' . '.jpg', $imagick); }
Example Function
Another example function, makeThumbnails() uses PHP's image functions to create thumbnails:
function makeThumbnails($updir, $img, $id) { $width = 134; $height = 189; $thumb_beforeword = "thumb"; list($original_width, $original_height) = getimagesize("$updir$id" . '_' . "$img"); if ($original_width > $original_height) { $new_width = $width; $new_height = intval($original_height * $new_width / $original_width); } else { $new_height = $height; $new_width = intval($original_width * $new_height / $original_height); } $old_image = imagecreatefromjpeg("$updir$id" . '_' . "$img"); $new_image = imagecreatetruecolor($width, $height); imagecopyresized($new_image, $old_image, intval(($width - $new_width) / 2), intval(($height - $new_height) / 2), 0, 0, $new_width, $new_height, $original_width, $original_height); imagejpeg($new_image, "$updir$id" . '_' . "$thumb_beforeword" . "$img"); }
By implementing these techniques, you can create and store thumbnails alongside the original images, optimizing website performance and enhancing user experience.
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