从上传的图像创建缩略图

php image gd thumbnails

2022-08-30 12:45:35

我想从用户上传的图像创建缩略图，以便图像看起来不会被挤压。但也想要原始图像的副本。因此，我希望原始图像将原始图像发送到我的服务器，并创建一个拇指版本并将其发送到我的服务器，以便我可以为每个上传自己图像的用户调用每个图像。

我的用户表有 2 个表

`user_pic` longblob NOT NULL,
`user_pic_small` longblob NOT NULL,

我对编码的图像方面并不热衷，但这就是我到目前为止所拥有的。

图像上传.php

> <form id="myForm" action="include/media.profileimage.upload.php"
> method="POST" enctype="multipart/form-data" target="ifr1">
>                   <input type = "file" name = "image_data" class = "input_text" style="width:800px;" >    
>                   <input type = "submit" name = "submit"   class = "btn_login" value = "Upload">
>         </form>

media.profileimage.upload.php

if(isset($_FILES['image_data'])){
       if(is_uploaded_file($_FILES['image_data']['tmp_name'])) {

            // prepare the image for insertion
                $imgData =addslashes (file_get_contents($_FILES['image_data']['tmp_name']));

            // get the image info..
              $size = getimagesize($_FILES['image_data']['tmp_name']);


            // our sql query
            $creator_id     =   $_SESSION['id'];
            $sql = "UPDATE users SET user_pic='".$imgData."' WHERE id=$creator_id";
            $sql2 = "INSERT INTO userphotos(photo_ownerid,photo_ispublic, photo_name, photo_caption, photo_imagedata) VALUES ($creator_id,1,'Profile Picture','Profile Picture','$imgData')";

            // insert the image
            if(!mysql_query($sql)) {
                echo "Fail. It broke.";
            }else{
            $c=mysql_query($sql2);

                echo "<script> parent.alert('Image Uploaded','',1000);</script>";
            }
        }
    }

将不胜感激任何帮助或指导。谢谢

答案 1

更新：

如果你想利用Imagick（如果它安装在你的服务器上）。注意：我没有使用Imagick的天性，因为我的服务器上遇到了问题。文件放置内容也同样有效。writeFile

<?php
/**
 * 
 * Generate Thumbnail using Imagick class
 *  
 * @param string $img
 * @param string $width
 * @param string $height
 * @param int $quality
 * @return boolean on true
 * @throws Exception
 * @throws ImagickException
 */
function generateThumbnail($img, $width, $height, $quality = 90)
{
    if (is_file($img)) {
        $imagick = new Imagick(realpath($img));
        $imagick->setImageFormat('jpeg');
        $imagick->setImageCompression(Imagick::COMPRESSION_JPEG);
        $imagick->setImageCompressionQuality($quality);
        $imagick->thumbnailImage($width, $height, false, false);
        $filename_no_ext = reset(explode('.', $img));
        if (file_put_contents($filename_no_ext . '_thumb' . '.jpg', $imagick) === false) {
            throw new Exception("Could not put contents.");
        }
        return true;
    }
    else {
        throw new Exception("No valid image provided with {$img}.");
    }
}

// example usage
try {
    generateThumbnail('test.jpg', 100, 50, 65);
}
catch (ImagickException $e) {
    echo $e->getMessage();
}
catch (Exception $e) {
    echo $e->getMessage();
}
?>

我一直在使用这个，只需在存储原始图像并使用该位置创建缩略图后执行该函数即可。根据您的喜好编辑它...

function makeThumbnails($updir, $img, $id)
{
    $thumbnail_width = 134;
    $thumbnail_height = 189;
    $thumb_beforeword = "thumb";
    $arr_image_details = getimagesize("$updir" . $id . '_' . "$img"); // pass id to thumb name
    $original_width = $arr_image_details[0];
    $original_height = $arr_image_details[1];
    if ($original_width > $original_height) {
        $new_width = $thumbnail_width;
        $new_height = intval($original_height * $new_width / $original_width);
    } else {
        $new_height = $thumbnail_height;
        $new_width = intval($original_width * $new_height / $original_height);
    }
    $dest_x = intval(($thumbnail_width - $new_width) / 2);
    $dest_y = intval(($thumbnail_height - $new_height) / 2);
    if ($arr_image_details[2] == IMAGETYPE_GIF) {
        $imgt = "ImageGIF";
        $imgcreatefrom = "ImageCreateFromGIF";
    }
    if ($arr_image_details[2] == IMAGETYPE_JPEG) {
        $imgt = "ImageJPEG";
        $imgcreatefrom = "ImageCreateFromJPEG";
    }
    if ($arr_image_details[2] == IMAGETYPE_PNG) {
        $imgt = "ImagePNG";
        $imgcreatefrom = "ImageCreateFromPNG";
    }
    if ($imgt) {
        $old_image = $imgcreatefrom("$updir" . $id . '_' . "$img");
        $new_image = imagecreatetruecolor($thumbnail_width, $thumbnail_height);
        imagecopyresized($new_image, $old_image, $dest_x, $dest_y, 0, 0, $new_width, $new_height, $original_width, $original_height);
        $imgt($new_image, "$updir" . $id . '_' . "$thumb_beforeword" . "$img");
    }
}

上述函数创建具有统一缩略图大小的图像。如果图像的尺寸与指定的缩略图大小不同（按比例），则其顶部和底部只有黑区。

答案 2

您可以使用最简单的方法

<?php
function make_thumb($src, $dest, $desired_width) {

    /* read the source image */
    $source_image = imagecreatefromjpeg($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);

    /* 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 */
    imagejpeg($virtual_image, $dest);
}

$src="1494684586337H.jpg";
$dest="new.jpg";
$desired_width="200";
make_thumb($src, $dest, $desired_width);
?>