PHP-创建缩略图&;保持纵横比
编辑:这可以很容易地用CSS完成,我在写这篇文章的时候对CSS不太了解PHP-创建缩略图&;保持纵横比,php,image,gd,image-resizing,Php,Image,Gd,Image Resizing,编辑:这可以很容易地用CSS完成,我在写这篇文章的时候对CSS不太了解 我已经用PHP创建了一个缩略图生成器。生成的缩略图大小应相同。但问题是使用具有不同纵横比(如横向或纵向)的上传图像,缩略图会变得难看。所以我创建了上面的图片来澄清。无论上传的图像是什么,它都将被放入一个矩形图像中。因此,纵横比不会改变,缩略图的大小将相同。谁能帮我一下或告诉我一些想法吗?看看我的的源代码:) 这里有一个函数可能对您有所帮助。你告诉它你想要保持的宽度,它会在生成缩略图的同时保持纵横比 public stati
我已经用PHP创建了一个缩略图生成器。生成的缩略图大小应相同。但问题是使用具有不同纵横比(如横向或纵向)的上传图像,缩略图会变得难看。所以我创建了上面的图片来澄清。无论上传的图像是什么,它都将被放入一个矩形图像中。因此,纵横比不会改变,缩略图的大小将相同。谁能帮我一下或告诉我一些想法吗?看看我的的源代码:)
这里有一个函数可能对您有所帮助。你告诉它你想要保持的宽度,它会在生成缩略图的同时保持纵横比
public static function makeThumb($src, $dest, $desired_width, $format = 'image/jpeg')
{
/* read the source image */
$source_image = null;
if($format == 'image/jpeg')
{
$source_image = imagecreatefromjpeg($src);
}
else if($format == 'image/png')
{
$source_image = imagecreatefrompng($src);
}
$width = imagesx($source_image);
$height = imagesy($source_image);
/* find the "desired height" of this thumbnail, relative to the desired width */
$desired_height = floor($height * ($desired_width / $width));
/* create a new, "virtual" image */
$virtual_image = imagecreatetruecolor($desired_width, $desired_height);
imageAlphaBlending($virtual_image, false);
imageSaveAlpha($virtual_image, true);
/* copy source image at a resized size */
imagecopyresampled($virtual_image, $source_image, 0, 0, 0, 0, $desired_width, $desired_height, $width, $height);
/* create the physical thumbnail image to its destination */
if($format == 'image/jpeg')
{
imagejpeg($virtual_image, $dest);
}
else if($format == 'image/png')
{
imagepng($virtual_image, $dest);
}
}
使用ImageMagick API。查看此
define('THUMB_WIDTH', 60);
define('THUMB_HEIGHT', 80);
define('MAGICK_PATH','/usr/local/bin/');
function makeThumbnail($in, $out) {
$width = THUMB_WIDTH;
$height = THUMB_HEIGHT;
list($w,$h) = getimagesize($in);
$thumbRatio = $width/$height;
$inRatio = $w/$h;
$isLandscape = $inRatio > $thumbRatio;
$size = ($isLandscape ? '1000x'.$height : $width.'x1000');
$xoff = ($isLandscape ? floor((($inRatio*$height)-$width)/2) : 0);
$command = MAGICK_PATH."convert $in -resize $size -crop {$width}x{$height}+{$xoff}+0 ".
"-colorspace RGB -strip -quality 90 $out";
exec($command);
}
请参阅此链接-或define('THUMBNAIL\u IMAGE\u MAX\u WIDTH',150);
定义(“缩略图图像最大高度”,150);
函数生成缩略图($source\u image\u path,$thumbnail\u image\u path)
{
列表($source\u image\u width、$source\u image\u height、$source\u image\u type)=getimagesize($source\u image\u path);
开关($source\u image\u type){
案例图像类型\u GIF:
$source\u gd\u image=imagecreatefromformgif($source\u image\u path);
打破
case IMAGETYPE_JPEG:
$source\u gd\u image=imagecreatefromjpeg($source\u image\u path);
打破
案例IMAGETYPE_PNG:
$source\u gd\u image=imagecreatefrompng($source\u image\u path);
打破
}
如果($source\u gd\u image===false){
返回false;
}
$source\u aspect\u ratio=$source\u image\u width/$source\u image\u height;
$thumbnail\u aspect\u ratio=缩略图图像最大宽度/缩略图图像最大高度;
如果($source\u image\u width我想这个资源会有帮助:@LeaveAirykson好的。让我试试…@LeaveAirykson谢谢。它起了一点作用。完成了一半。现在我需要的是把获得的图像放在一个白色的矩形中。你能帮我吗?看看这个答案,可能会有帮助的。看看这个帖子,这可能会对你有所帮助。@lewisd我试过这个。它只是调整图像的大小,而不是根据我在图片中显示的图像。我对PHP不熟悉。你能告诉我如何调用此函数,文件名放在哪里,目的地是这样的吗???@user3392772单击链接。查看示例下的使用示例。PHP
将$image
变量更改为$image=$\u获取['i']
将允许您在基本HTML标记中链接图像,如
您还可以将最大宽度和高度变量更改为查询,以便动态定义宽度/高度
我使用函数make缩略图('test.jpg','new.jpg')调用它;但没有发生任何事情。您必须安装ImageMagick。检查此项-在服务器中安装它如何?可能吗?是的,在第37行中肯定有可能,它必须是$img\u disp=ImageCreateTureColor(缩略图\u IMAGE\u MAX\u WIDTH,缩略图\u IMAGE\u MAX\u HEIGHT);(用缩略图\u IMAGE\u MAX\u HEIGHT替换第二个参数)。这不适用于带有黑色文本的PNG透明图像,会创建黑色图像。
define('THUMB_WIDTH', 60);
define('THUMB_HEIGHT', 80);
define('MAGICK_PATH','/usr/local/bin/');
function makeThumbnail($in, $out) {
$width = THUMB_WIDTH;
$height = THUMB_HEIGHT;
list($w,$h) = getimagesize($in);
$thumbRatio = $width/$height;
$inRatio = $w/$h;
$isLandscape = $inRatio > $thumbRatio;
$size = ($isLandscape ? '1000x'.$height : $width.'x1000');
$xoff = ($isLandscape ? floor((($inRatio*$height)-$width)/2) : 0);
$command = MAGICK_PATH."convert $in -resize $size -crop {$width}x{$height}+{$xoff}+0 ".
"-colorspace RGB -strip -quality 90 $out";
exec($command);
}
define('THUMBNAIL_IMAGE_MAX_WIDTH', 150);
define('THUMBNAIL_IMAGE_MAX_HEIGHT', 150);
function generate_image_thumbnail($source_image_path, $thumbnail_image_path)
{
list($source_image_width, $source_image_height, $source_image_type) = getimagesize($source_image_path);
switch ($source_image_type) {
case IMAGETYPE_GIF:
$source_gd_image = imagecreatefromgif($source_image_path);
break;
case IMAGETYPE_JPEG:
$source_gd_image = imagecreatefromjpeg($source_image_path);
break;
case IMAGETYPE_PNG:
$source_gd_image = imagecreatefrompng($source_image_path);
break;
}
if ($source_gd_image === false) {
return false;
}
$source_aspect_ratio = $source_image_width / $source_image_height;
$thumbnail_aspect_ratio = THUMBNAIL_IMAGE_MAX_WIDTH / THUMBNAIL_IMAGE_MAX_HEIGHT;
if ($source_image_width <= THUMBNAIL_IMAGE_MAX_WIDTH && $source_image_height <= THUMBNAIL_IMAGE_MAX_HEIGHT) {
$thumbnail_image_width = $source_image_width;
$thumbnail_image_height = $source_image_height;
} elseif ($thumbnail_aspect_ratio > $source_aspect_ratio) {
$thumbnail_image_width = (int) (THUMBNAIL_IMAGE_MAX_HEIGHT * $source_aspect_ratio);
$thumbnail_image_height = THUMBNAIL_IMAGE_MAX_HEIGHT;
} else {
$thumbnail_image_width = THUMBNAIL_IMAGE_MAX_WIDTH;
$thumbnail_image_height = (int) (THUMBNAIL_IMAGE_MAX_WIDTH / $source_aspect_ratio);
}
$thumbnail_gd_image = imagecreatetruecolor($thumbnail_image_width, $thumbnail_image_height);
imagecopyresampled($thumbnail_gd_image, $source_gd_image, 0, 0, 0, 0, $thumbnail_image_width, $thumbnail_image_height, $source_image_width, $source_image_height);
$img_disp = imagecreatetruecolor(THUMBNAIL_IMAGE_MAX_WIDTH,THUMBNAIL_IMAGE_MAX_WIDTH);
$backcolor = imagecolorallocate($img_disp,0,0,0);
imagefill($img_disp,0,0,$backcolor);
imagecopy($img_disp, $thumbnail_gd_image, (imagesx($img_disp)/2)-(imagesx($thumbnail_gd_image)/2), (imagesy($img_disp)/2)-(imagesy($thumbnail_gd_image)/2), 0, 0, imagesx($thumbnail_gd_image), imagesy($thumbnail_gd_image));
imagejpeg($img_disp, $thumbnail_image_path, 90);
imagedestroy($source_gd_image);
imagedestroy($thumbnail_gd_image);
imagedestroy($img_disp);
return true;
}
generate_image_thumbnail('original_image.jpg', 'thumb_image.jpg'); //call the function