最好的方法是在上传之前调整它们的大小。
您还可以尝试使用此功能动态调整图像大小。
<?php
/*
* Resize images dynamically using wp built in functions
* Victor Teixeira
*
* php 5.2+
*
* Exemplo de uso:
*
* <?php
* $thumb = get_post_thumbnail_id();
* $image = vt_resize( $thumb, \'\', 140, 110, true );
* ?>
* <img src="<?php echo $image[url]; ?>" width="<?php echo $image[width]; ?>" height="<?php echo $image[height]; ?>" />
*
* @param int $attach_id
* @param string $img_url
* @param int $width
* @param int $height
* @param bool $crop
* @return array
*/
if ( !function_exists( \'vt_resize\') ) {
function vt_resize( $attach_id = null, $img_url = null, $width, $height, $crop = false ) {
// this is an attachment, so we have the ID
if ( $attach_id ) {
$image_src = wp_get_attachment_image_src( $attach_id, \'full\' );
$file_path = get_attached_file( $attach_id );
// this is not an attachment, let\'s use the image url
} else if ( $img_url ) {
$file_path = parse_url( $img_url );
$file_path = $_SERVER[\'DOCUMENT_ROOT\'] . $file_path[\'path\'];
// Look for Multisite Path
if(file_exists($file_path) === false){
global $blog_id;
$file_path = parse_url( $img_url );
if (preg_match("/files/", $file_path[\'path\'])) {
$path = explode(\'/\',$file_path[\'path\']);
foreach($path as $k=>$v){
if($v == \'files\'){
$path[$k-1] = \'wp-content/blogs.dir/\'.$blog_id;
}
}
$path = implode(\'/\',$path);
}
$file_path = $_SERVER[\'DOCUMENT_ROOT\'].$path;
}
//$file_path = ltrim( $file_path[\'path\'], \'/\' );
//$file_path = rtrim( ABSPATH, \'/\' ).$file_path[\'path\'];
$orig_size = getimagesize( $file_path );
$image_src[0] = $img_url;
$image_src[1] = $orig_size[0];
$image_src[2] = $orig_size[1];
}
$file_info = pathinfo( $file_path );
// check if file exists
$base_file = $file_info[\'dirname\'].\'/\'.$file_info[\'filename\'].\'.\'.$file_info[\'extension\'];
if ( !file_exists($base_file) )
return;
$extension = \'.\'. $file_info[\'extension\'];
// the image path without the extension
$no_ext_path = $file_info[\'dirname\'].\'/\'.$file_info[\'filename\'];
$cropped_img_path = $no_ext_path.\'-\'.$width.\'x\'.$height.$extension;
// checking if the file size is larger than the target size
// if it is smaller or the same size, stop right here and return
if ( $image_src[1] > $width ) {
// the file is larger, check if the resized version already exists (for $crop = true but will also work for $crop = false if the sizes match)
if ( file_exists( $cropped_img_path ) ) {
$cropped_img_url = str_replace( basename( $image_src[0] ), basename( $cropped_img_path ), $image_src[0] );
$vt_image = array (
\'url\' => $cropped_img_url,
\'width\' => $width,
\'height\' => $height
);
return $vt_image;
}
// $crop = false or no height set
if ( $crop == false OR !$height ) {
// calculate the size proportionaly
$proportional_size = wp_constrain_dimensions( $image_src[1], $image_src[2], $width, $height );
$resized_img_path = $no_ext_path.\'-\'.$proportional_size[0].\'x\'.$proportional_size[1].$extension;
// checking if the file already exists
if ( file_exists( $resized_img_path ) ) {
$resized_img_url = str_replace( basename( $image_src[0] ), basename( $resized_img_path ), $image_src[0] );
$vt_image = array (
\'url\' => $resized_img_url,
\'width\' => $proportional_size[0],
\'height\' => $proportional_size[1]
);
return $vt_image;
}
}
// check if image width is smaller than set width
$img_size = getimagesize( $file_path );
if ( $img_size[0] <= $width ) $width = $img_size[0];
// Check if GD Library installed
if (!function_exists (\'imagecreatetruecolor\')) {
echo \'GD Library Error: imagecreatetruecolor does not exist - please contact your webhost and ask them to install the GD library\';
return;
}
// no cache files - let\'s finally resize it
$new_img_path = image_resize( $file_path, $width, $height, $crop );
$new_img_size = getimagesize( $new_img_path );
$new_img = str_replace( basename( $image_src[0] ), basename( $new_img_path ), $image_src[0] );
// resized output
$vt_image = array (
\'url\' => $new_img,
\'width\' => $new_img_size[0],
\'height\' => $new_img_size[1]
);
return $vt_image;
}
// default output - without resizing
$vt_image = array (
\'url\' => $image_src[0],
\'width\' => $width,
\'height\' => $height
);
return $vt_image;
}
}
把它放在你的主题函数中。php文件。您可以在主题中使用它，如下所示：
<?php $image = vt_resize(get_post_thumbnail_id(), \'\', 277, 115, true); ?>
<img src="<?php echo $image[url]; ?>" width="<?php echo $image[width]; ?>" height="<?php echo $image[height]; ?>" />
本页概述了您可以采取的一些步骤，以进一步优化您的网站，并基于YSlow的建议。我强烈推荐W3 Total Cache和Yahoo的Smush。it插件。
http://wp.tutsplus.com/tutorials/10-quick-tips-optimizing-speeding-up-your-wordpress-site/
