Question

我有一个问题陈述，需要保持上传图片的宽高比。

上传照片时，您需要创建三种尺寸，a） 310X230（Thumnail）b）960X400（详细图片）c）原稿尺寸（全尺寸）图像）将使用精确尺寸创建尺寸。如果是照片不是任何尺寸的宽高比，然后按比例缩放到那个尺寸，并裁掉额外部分。

我已经使用php GD库上传了3种不同大小的图像，其代码如下

    if($_SERVER["REQUEST_METHOD"] == "POST")
 {
    $image =$_FILES["file"]["name"];
    $uploadedfile = $_FILES['file']['tmp_name'];


    if ($image) 
    {

        $filename = stripslashes($_FILES['file']['name']);

        $extension = getExtension($filename);
        $extension = strtolower($extension);


 if (($extension != "jpg") && ($extension != "jpeg") && ($extension != "png") && ($extension != "gif")) 
        {

            $change='<div class="msgdiv">Unknown Image extension </div> ';
            $errors=1;
        }
        else
        {

 $size=filesize($_FILES['file']['tmp_name']);


if ($size > MAX_SIZE*1024)
{
    $change='<div class="msgdiv">You have exceeded the size limit!</div> ';
    $errors=1;
}


if($extension=="jpg" || $extension=="jpeg" )
{
$uploadedfile = $_FILES['file']['tmp_name'];
$src = imagecreatefromjpeg($uploadedfile);

}
else if($extension=="png")
{
$uploadedfile = $_FILES['file']['tmp_name'];
$src = imagecreatefrompng($uploadedfile);

}
else 
{
$src = imagecreatefromgif($uploadedfile);
}

//echo $src;

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


$newwidth=$width;
$newheight=($height/$width)*$newwidth;
$tmp=imagecreatetruecolor($newwidth,$newheight);


$newwidth1=310;
$newheight1=230;
$tmp1=imagecreatetruecolor($newwidth1,$newheight1);


$newwidth2=960;
$newheight2=400;
$tmp2=imagecreatetruecolor($newwidth2,$newheight2);

imagecopyresampled($tmp,$src,0,0,0,0,$newwidth,$newheight,$width,$height);

imagecopyresampled($tmp1,$src,0,0,0,0,$newwidth1,$newheight1,$width,$height);

imagecopyresampled($tmp2,$src,0,0,0,0,$newwidth2,$newheight2,$width,$height);

$filename = "images/medium/". $_FILES['file']['name'];

$filename1 = "images/thumbnail/small". $_FILES['file']['name'];

$filename2 = "images/full/". $_FILES['file']['name'];


imagejpeg($tmp,$filename,100);

imagejpeg($tmp1,$filename1,100);

imagejpeg($tmp2,$filename2,100);

imagedestroy($src);
imagedestroy($tmp);
imagedestroy($tmp1);
imagedestroy($tmp2);
}}

}

Answer 1

It is quite complicated to both resize and crop multiple images, but here's a solution that might work for you:

 if($_SERVER["REQUEST_METHOD"] == "POST"){
    $image =$_FILES["file"]["name"];
    $uploadedfile = $_FILES['file']['tmp_name'];

    if($image){
        $filename = stripslashes($_FILES['file']['name']);
        $extension = getExtension($filename);
        $extension = strtolower($extension);

        if(($extension != "jpg") && ($extension != "jpeg") && ($extension != "png") && ($extension != "gif")) {
            $change='<div class="msgdiv">Unknown Image extension </div> ';
            $errors=1;
        } else {
            $size=filesize($_FILES['file']['tmp_name']);

            if($size > MAX_SIZE*1024){
                $change='<div class="msgdiv">You have exceeded the size limit!</div> ';
                $errors=1;
            }

            if($extension=="jpg" || $extension=="jpeg" ) {
                $uploadedfile = $_FILES['file']['tmp_name'];
                $src = imagecreatefromjpeg($uploadedfile);
            } else if($extension=="png"){
                $uploadedfile = $_FILES['file']['tmp_name'];
                $src = imagecreatefrompng($uploadedfile);
            } else {
                $src = imagecreatefromgif($uploadedfile);
            }


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

        /* ORIGINAL ASPECT RATIO */     
        $original_aspect_ratio = $width / $height;

        /* RESIZE AND CROP THUMBNAIL (MEDIUM SIZE) */
        $new_width = 960; // SET DESIRED WIDTH
        $new_height = 400; // SET DESIRED HEIGHT    
        $new_aspect_ratio = $new_width / $new_height;

        if ($original_aspect_ratio > $new_aspect_ratio) {
            /* source image is wider */
            $temp_height = $new_height;
            $temp_width = (int) ($new_height * $original_aspect_ratio);
        } else {
            /* source image is similar or taller */
            $temp_width = $new_width;
            $temp_height = (int) ($new_width / $original_aspect_ratio);
        }

        /* Resize to a temporary GD image */
        $temp = imagecreatetruecolor($temp_width, $temp_height);
        imagecopyresampled($temp,$src,0,0,0,0,$temp_width,$temp_height,$width,$height);

        /* Copy cropped region from temporary image into the desired GD image */
        $x0 = ($temp_width - $new_width) / 2;
        $y0 = ($temp_height - $new_height) / 2;
        $medium = imagecreatetruecolor($new_width, $new_height);
        imagecopy($medium,$temp,0,0,$x0,$y0,$new_width,$new_height);

        /* SAVE TO FILE AND CLEAN UP */
        imagedestroy($temp);// CLEANUP TEMP IMAGE
        $medium_filename = "images/medium/". $_FILES['file']['name'];
        imagejpeg($medium,$medium_filename,100);
        imagedestroy($medium);

        /* RESIZE AND CROP SMALL IMAGES, SAME PROCEDURE AS ABOVE */
        $new_width = 310; // SET DESIRED WIDTH
        $new_height = 230; // SET DESIRED HEIGHT    
        $new_aspect_ratio = $new_width / $new_height;

        if ($original_aspect_ratio > $new_aspect_ratio) {
            $temp_height = $new_height;
            $temp_width = (int) ($new_height * $original_aspect_ratio);
        } else {
            $temp_width = $new_width;
            $temp_height = (int) ($new_width / $original_aspect_ratio);
        }

        $temp = imagecreatetruecolor($temp_width, $temp_height);
        imagecopyresampled($temp,$src,0,0,0,0,$temp_width,$temp_height,$width,$height);

        $x0 = ($temp_width - $new_width) / 2;
        $y0 = ($temp_height - $new_height) / 2;
        $small = imagecreatetruecolor($new_width, $new_height);
        imagecopy($small,$temp,0,0,$x0,$y0,$new_width,$new_height);

        /* SAVE TO FILE AND CLEAN UP */
        imagedestroy($temp);// CLEANUP TEMP IMAGE
        $small_filename = "images/thumbnail/small". $_FILES['file']['name'];
        imagejpeg($small,$small_filename,100);
        imagedestroy($small);


        /* ORIGINAL SIZE. NO RESIZING OR CROPPING... NOT NEEDED? YOU DECIDE... */           
        $full=imagecreatetruecolor($width,$height);
        imagecopyresampled($full,$src,0,0,0,0,$width,$height,$width,$height);

        /* SAVE TO FILE AND CLEAN UP */
        $full_filename = "images/full/". $_FILES['file']['name']; // ORIGINAL
        imagejpeg($full,$full_filename,100);
        imagedestroy($full);

        imagedestroy($src); // CLEAN UP ORIGINAL SOURCE FILE

        }
    }
}

The code is not tested and mainly inspired from this blog post: http://salman-w.blogspot.se/2009/04/crop-to-fit-image-using-aspphp.html

It is a lot of repeating code in my suggested solution since you have multiple images. You could consider to chunk some of the repeated code into smaller reusable functions, for instance the calculation of aspect ratio for the different images.

如何在调整上传图像大小时保持宽高比

1 个答案: