php调整图像大小然后裁剪图像问题

Question

我想将图片大小从 600px * 500px 减小到 60px * 50px 大小，然后将其裁剪为 50px *50px。我有两组代码，一组是缩小图像的大小，另一组是裁剪图像。问题是它们是分开工作的，如何将这两组代码组合起来使它们一起工作？以下是我的代码:

<?php

//codes of group A - Reduce the size of image from 600px * 500px to 60px * 50px   
    $save2 = "images/users/" . $image_name_2; //This is the new file you saving
    list($width2, $height2) = getimagesize($file) ; 
    $modwidth2 = 50; 
    $diff2 = $width2 / $modwidth2;
    $modheight2 = $height2 / $diff2; 
    $tn2 = imagecreatetruecolor($modwidth2, $modheight2) ; 
    $image2 = imagecreatefromjpeg($file) ; 
    imagecopyresampled($tn2, $image2, 0, 0, 0, 0, $modwidth2, $modheight2, $width2, $height2) ; 
    imagejpeg($tn2, $save2, 100) ; 



//codes of group B - Crop the image from 60px * 50px to 50px * 50px 
    $save3 = "images/users/" . $image_name_3;  
    list($width3, $height3) = getimagesize($file) ; 
    $modwidth3 = 60;  
    $diff3 = $width3 / $modwidth3;
    $modheight3 = $height3 / $diff3; 

    $left = 0; 
    $top = 0;

    $cropwidth = 50; //thumb size
    $cropheight = 50;

    $tn3 = imagecreatetruecolor($cropwidth, $cropheight) ; 
    $image3 = imagecreatefromjpeg($file) ; 
    imagecopyresampled($tn3, $image3, 0, 0, $left, $top, $cropwidth, $cropheight, $modwidth3, $modheight3) ; 
    imagejpeg($tn3, $save3, 100) ; //save the cropped image
?>

从上面的两组代码中可以看出，第一组调整图片大小，然后将其保存到文件夹中。第二组代码裁剪图片，然后将其保存到文件夹中。我的问题是......在第一组代码调整图片大小后，是否有必要将其保存到文件夹中才能裁剪它？如果有必要，那么我需要编写新的代码行以从文件夹中检索调整大小的图片，以便第二组代码进行裁剪？如果没有必要，在调整图片大小后，如何将图片传递给第二组代码以裁剪它？

Answer 1

你是@zac1987。
完整 PHP 代码生成所需大小的方形缩略图而不拉伸(stretch)图像。该代码支持 png 和 jpg/jpeg 图像扩展。只需将设置部分更改为所需的部分。您可以复制粘贴代码并在您的网络服务器上进行测试。

<?php

    // SETTINGS
    $image_name = 'file.jpg';    // Full path and image name with extension
    $thumb_name = 'thumbnail';   // Generated thumbnail name without extension
    $thumb_side = 100;           // Desired thumbnail side size
    // END OF SETTINGS

    $image_extension = explode('.', $image_name); // I assume that images are named only following 'imagename.ext' pattern

    if (preg_match('/jpg|jpeg/', $image_extension[1])) {
        $src_image = imagecreatefromjpeg($image_name);
        $image_extension = 'jpg';
    } else if (preg_match('/png/', $image_extension[1])) {
        $src_image = imagecreatefrompng($image_name);
        $image_extension = 'png';
    }

    $src_width = imageSX($src_image);   // Width of the original image
    $src_height = imageSY($src_image);  // Height of the original image

    $min_side = min($src_width, $src_height);

    /*********** If you need this part uncomment it
    $ratio = $min_side / $thumb_width;
    $new_width = floor($src_width / $ratio);
    $new_height = floor($src_height / $ratio);
    **********************************************/    

    $dst_image = imagecreatetruecolor($thumb_side, $thumb_side);

    imagecopyresampled($dst_image, $src_image, 0, 0, 0, 0, $thumb_side, $thumb_side, $min_side, $min_side);

    switch ($image_extension)
    {
        case 'jpg':
            imagejpeg($dst_image, $thumb_name . '.jpg', 100);
            break;
        case 'png':
            imagepng($dst_image, $thumb_name . '.jpg', 100);
            break;
    }

    imagedestroy($src_image);
    imagedestroy($dst_image);

?>