我目前正在使用的PHP脚本根据最大宽度和高度创建缩略图。但是,我希望它能够始终创建方形图像并在需要时裁剪图像。
以下是我现在使用的内容:
function makeThumb( $filename, $type ) {
global $max_width, $max_height;
if ( $type == 'jpg' ) {
$src = imagecreatefromjpeg("blocks/img/gallery/" . $filename);
} else if ( $type == 'png' ) {
$src = imagecreatefrompng("blocks/img/gallery/" . $filename);
} else if ( $type == 'gif' ) {
$src = imagecreatefromgif("blocks/img/gallery/" . $filename);
}
if ( ($oldW = imagesx($src)) < ($oldH = imagesy($src)) ) {
$newW = $oldW * ($max_width / $oldH);
$newH = $max_height;
} else {
$newW = $max_width;
$newH = $oldH * ($max_height / $oldW);
}
$new = imagecreatetruecolor($newW, $newH);
imagecopyresampled($new, $src, 0, 0, 0, 0, $newW, $newH, $oldW, $oldH);
if ( $type == 'jpg' ) {
imagejpeg($new, 'blocks/img/gallery/thumbs/'.$filename);
} else if ( $type == 'png' ) {
imagepng($new, 'blocks/img/gallery/thumbs/'.$filename);
} else if ( $type == 'gif' ) {
imagegif($new, 'blocks/img/gallery/thumbs/'.$filename);
}
imagedestroy($new);
imagedestroy($src);
}
我如何改变这个来完成我想要的东西(方形拇指)?
提前致谢。
答案 0 :(得分:15)
function makeThumb( $filename , $thumbSize=100 ){
global $max_width, $max_height;
/* Set Filenames */
$srcFile = 'blocks/img/gallery/'.$filename;
$thumbFile = 'blocks/img/gallery/thumbs/'.$filename;
/* Determine the File Type */
$type = substr( $filename , strrpos( $filename , '.' )+1 );
/* Create the Source Image */
switch( $type ){
case 'jpg' : case 'jpeg' :
$src = imagecreatefromjpeg( $srcFile ); break;
case 'png' :
$src = imagecreatefrompng( $srcFile ); break;
case 'gif' :
$src = imagecreatefromgif( $srcFile ); break;
}
/* Determine the Image Dimensions */
$oldW = imagesx( $src );
$oldH = imagesy( $src );
/* Calculate the New Image Dimensions */
if( $oldH > $oldW ){
/* Portrait */
$newW = $thumbSize;
$newH = $oldH * ( $thumbSize / $newW );
}else{
/* Landscape */
$newH = $thumbSize;
$newW = $oldW * ( $thumbSize / $newH );
}
/* Create the New Image */
$new = imagecreatetruecolor( $thumbSize , $thumbSize );
/* Transcribe the Source Image into the New (Square) Image */
imagecopyresampled( $new , $src , 0 , 0 , ( $newW-$thumbSize )/2 , ( $newH-$thumbSize )/2 , $thumbSize , $thumbSize , $oldW , $oldH );
switch( $type ){
case 'jpg' : case 'jpeg' :
$src = imagejpeg( $new , $thumbFile ); break;
case 'png' :
$src = imagepng( $new , $thumbFile ); break;
case 'gif' :
$src = imagegif( $new , $thumbFile ); break;
}
imagedestroy( $new );
imagedestroy( $src );
}
答案 1 :(得分:10)
/* Calculate the New Image Dimensions */
$limiting_dim = 0;
if( $oldH > $oldW ){
/* Portrait */
$limiting_dim = $oldW;
}else{
/* Landscape */
$limiting_dim = $oldH;
}
/* Create the New Image */
$new = imagecreatetruecolor( $thumbSize , $thumbSize );
/* Transcribe the Source Image into the New (Square) Image */
imagecopyresampled( $new , $src , 0 , 0 , ($oldW-$limiting_dim )/2 , ( $oldH-$limiting_dim )/2 , $thumbSize , $thumbSize , $limiting_dim , $limiting_dim );
我没有足够的业力来评论接受的答案(Lucanos'),但我发现上面的答案在缩略图的一侧给出了黑条。
此代码段(与已接受的答案相结合)应复制src图像的相关部分,而不会越界并产生黑条。根据原始问题,缩略图仍然是正方形。
答案 2 :(得分:3)
你想计算一个偏移而不是一个新的宽度/高度,以便新样本保持成比例,然后在生成新图像时使用偏移并给它一个固定的宽度/高度,以便它将被裁剪为一个正方形。一个快速示例,可以制作100x100拇指(注意:未经测试),
// Get dimensions of the src image.
list($oldW, $oldH) = getimagesize($filename);
// Work out what offset to use
if ($oldH < $oldW)
{
$offH = 0;
$offW = ($oldW-$oldH)/2;
$oldW = $oldH;
}
elseif ($oldH > $oldW)
{
$offW = 0;
$offH = ($oldH-$oldW)/2;
$oldH = $oldW;
}
else
{
$offW = 0;
$offH = 0;
}
// Resample the image into the new dimensions.
$new = imagecreatetruecolor(100, 100);
imagecopyresampled($new, $src, 0, 0, $offW, $offH, 100, 100, $oldW, $oldH);
答案 3 :(得分:0)
这个修改过的功能对我很有用
public function igImagePrepare($img,$name){
$dir = 'my-images/';
$img_name = $name.'-'.uniqid().'.jpg';
//Your Image
$imgSrc = $img;
//getting the image dimensions
list($width, $height) = getimagesize($imgSrc);
//saving the image into memory (for manipulation with GD Library)
$myImage = imagecreatefromjpeg($imgSrc);
$square_size = 400;
$width = imagesx( $myImage );
$height = imagesy( $myImage );
//set dimensions
if($width> $height) {
$width_t=$square_size;
//respect the ratio
$height_t=round($height/$width*$square_size);
//set the offset
$off_y=ceil(($width_t-$height_t)/2);
$off_x=0;
} elseif($height> $width) {
$height_t=$square_size;
$width_t=round($width/$height*$square_size);
$off_x=ceil(($height_t-$width_t)/2);
$off_y=0;
}
else {
$width_t=$height_t=$square_size;
$off_x=$off_y=0;
}
/* Create the New Image */
$new = imagecreatetruecolor( $square_size , $square_size );
/* Transcribe the Source Image into the New (Square) Image */
$bg = imagecolorallocate ( $new, 255, 255, 255 );
imagefill ( $new, 0, 0, $bg );
imagecopyresampled( $new , $myImage , $off_x, $off_y, 0, 0, $width_t, $height_t, $width, $height );
//final output
imagejpeg($new, $dir.$img_name);
return $dir.$img_name;
}