使用PHP调整图像大小，检测最长边并根据调整大小? [英] Resize image with PHP, detect longest side, and resize according?

问题描述

我正在使用PHP处理图像上传脚本，我发现有人提供了该脚本并尝试对其进行修改，但是，我遇到了一些问题.

I'm working on an image upload script with PHP, I found one someone was offering and tried modifying it, however, i'm running into a few problems.

我要执行以下操作: 检测图像的最长边(即纵向或横向) 然后调整图像大小，最长边为800px并保持比例.

I want to do the following: Detect the longest side of the image (ie. portrait or landscape) And then resize the image, with the longest side being 800px AND keep proportions.

这是我到目前为止所拥有的代码.对于横向图像，它可以正常工作，但是对于纵向图像，它像疯了似的扭曲了它们. PS.我正在制作更大的图像以及缩略图.

Here is the code I have so far.. For landscape images it works fine, but with portrait ones it distorts them like crazy. PS. I'm making a larger image as well as a thumbnail.

list($width,$height)=getimagesize($uploadedfile);

if($width > $height){

    $newwidth=800;
    $newheight=($height/$width)*$newwidth;

    $newwidth1=150;
    $newheight1=($height/$width)*$newwidth1;

} else {


    $newheight=800;
    $newwidth=($height/$width)*$newheight;


    $newheight1=150;
    $newwidth1=($height/$width)*$newheight;

}
$tmp=imagecreatetruecolor($newwidth,$newheight);
$tmp1=imagecreatetruecolor($newwidth1,$newheight1);

推荐答案

您可能会误会:

当$width > $height表示风景.将最大宽度设置为800表示(高度/宽度)* 800 =新高度.另一方面，$height > $width表示将maxheight设置为800，因此(width/height)* 800是新宽度.

When $width > $height that means it's landscape. Setting maxwidth to 800 means (height/width)*800 = new height. On the other hand $height > $width means setting maxheight to 800 and thus having (width/height)*800 is new width.

现在，您既可以使用高度/宽度比例，也可以使用其他比例.示例:

Right now your using both the height/width ratio instead of the other way around. Example:

Image: 1600 (w) x 1200 (h)
Type: Landscape
New Width: 800
New Height: (1200 (h) / 1600(w) * 800 (nw) = 600

Image 1200 (w) x 1600 (h)
Type: Portrait
New Height: 800
New Width: (1200 (w) / 1600(h) * 800 (nh) = 600

希望您能理解我的意思，您只是将它们切换了:)另外请注意，您为肖像缩略图乘以$ newheight而不是$ newheight1

Hope you get what I'm saying, you just switched them :) Also notice that you multiply with $newheight instead of $newheight1 for the portrait thumbnail

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