php - 如何制作不同尺寸/大小的单个图像

Question

实际上，我想要这样，当我上传一张图片时，原始图片将存储在 upload/og/ 中。但我也想要不同尺寸的图像，如 1366x768 、 1280*600 、 768x1024 等...不仅仅是这些尺寸，它会该图像的比例。

我有一个代码，可以将该图像转换为具有比例的拇指，这适用于 max-width=300 和 max-height=600。

define ("MAX_SIZE","100");
define ("WIDTH","300");
define ("HEIGHT","600");
function make_thumb($img_name,$filename,$new_w,$new_h)
{
    $ext=getExtension($img_name);
    if(!strcmp("jpg",$ext) || !strcmp("jpeg",$ext))
        $src_img=imagecreatefromjpeg($img_name);
    if(!strcmp("png",$ext))
        $src_img=imagecreatefrompng($img_name);

    //gets the dimmensions of the image
    $old_x=imageSX($src_img);
    $old_y=imageSY($src_img);

    // next we will calculate the new dimmensions for the thumbnail image
    $ratio1=$old_x/$new_w;
    $ratio2=$old_y/$new_h;
    if($ratio1>$ratio2) {
        $thumb_w=$new_w;
        $thumb_h=$old_y/$ratio1;
    }
    else {
        $thumb_h=$new_h;
        $thumb_w=$old_x/$ratio2;
    }
    $dst_img=ImageCreateTrueColor($thumb_w,$thumb_h);
    imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y); // resize the big image to the new created one

    if(!strcmp("png",$ext)) // output the created image to the file. Now we will have the thumbnail into the file named by $filename
        imagepng($dst_img,$filename);
    else
        imagejpeg($dst_img,$filename);

    imagedestroy($dst_img);
    imagedestroy($src_img);
}
function getExtension($str) {
    $i = strrpos($str,".");
    if (!$i) { return ""; }
    $l = strlen($str) - $i;
    $ext = substr($str,$i+1,$l);
    return $ext;
}

$errors=0;
if(isset($_POST['submit']))
    {
    //reads the name of the file the user submitted for uploading
    $image=$_FILES['scrnsots']['name'];
    if ($image)
    {
        $filename = stripslashes($_FILES['scrnsots']['name']);
        // get the extension of the file in a lower case format
        $extension = getExtension($filename);
        $extension = strtolower($extension);
        // if it is not a known extension, we will suppose it is an error, print an error message
        //and will not upload the file, otherwise we continue
        if (($extension != "jpg") && ($extension != "jpeg") && ($extension != "png"))
        {
            echo '<h1>Unknown extension!</h1>';
            $errors=1;
        }
        else
        {
            $size=getimagesize($_FILES['scrnsots']['tmp_name']);
            $sizekb=filesize($_FILES['scrnsots']['tmp_name']);
            if ($sizekb > MAX_SIZE*102400)
            {
                echo '<h1>You have exceeded the size limit!</h1>';
                $errors=1;
            }
            $image_name= $image .''. time() .'.'.$extension;
            $newname="uploads/scrnsots/".$image_name;
            $copied = copy($_FILES['scrnsots']['tmp_name'], $newname);
            if (!$copied)
            {
                echo '<h1>Copy unsuccessfull!</h1>';
                $errors=1;
            }
            else
            {
                $thumb_name='uploads/scrnsots/thumb/thumb-'.$image_name;
                $thumb=make_thumb($newname,$thumb_name,WIDTH,HEIGHT);
            }
        }
    }
}
if(isset($_POST['submit']) && !$errors)
{
    echo $thumb_name ."<br/>";


        echo "<div class='custom alert alert-success'>Successfully Added.<a href='#' class='close' data-dismiss='alert' aria-label='close'>&times;</a></div>";
}

但它只会创建拇指。我想要一张不同尺寸(高度 - 宽度)的图像。

Answer 1

如评论所述，您实际上只需将最后一部分(函数)放入循环中并使用 mkdir() 添加一些目录创建逻辑。还有一个本地函数可以提取名为 pathinfo() 的扩展，所以只需使用那个函数而不是你拥有的函数:

function make_thumb($img_name,$filename,$new_w,$new_h)
    {
        $ext=getExtension($img_name);
        if(!strcmp("jpg",$ext) || !strcmp("jpeg",$ext))
            $src_img=imagecreatefromjpeg($img_name);
        if(!strcmp("png",$ext))
            $src_img=imagecreatefrompng($img_name);

        $old_x=imageSX($src_img);
        $old_y=imageSY($src_img);

        $ratio1=$old_x/$new_w;
        $ratio2=$old_y/$new_h;
        if($ratio1>$ratio2) {
            $thumb_w=$new_w;
            $thumb_h=$old_y/$ratio1;
        }
        else {
            $thumb_h=$new_h;
            $thumb_w=$old_x/$ratio2;
        }
        $dst_img = ImageCreateTrueColor($thumb_w,$thumb_h);
        imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y); // resize the big image to the new created one

        if(!strcmp("png",$ext)) // output the created image to the file. Now we will have the thumbnail into the file named by $filename
            imagepng($dst_img,$filename);
        else
            imagejpeg($dst_img,$filename);

        imagedestroy($dst_img);
        imagedestroy($src_img);
    }

if(!empty($_FILES)) {
    $errors=0;
    if($_POST['submit']) {
        if($_FILES['scrnsots']['error'] == 0) {
            $image  =   $_FILES['scrnsots']['name'];
            $filename = stripslashes($_FILES['scrnsots']['name']);
            $extension = pathinfo($filename,PATHINFO_EXTENSION);
            $extension = strtolower($extension);
            if (($extension != "jpg") && ($extension != "jpeg") && ($extension != "png")) {
                echo '<h1>Unknown extension!</h1>';
                $errors=1;
            }
            else {
                $size   =   getimagesize($_FILES['scrnsots']['tmp_name']);
                $sizekb =   filesize($_FILES['scrnsots']['tmp_name']);
                if ($sizekb > MAX_SIZE*102400) {
                    echo '<h1>You have exceeded the size limit!</h1>';
                    $errors=1;
                }

                $image_name =   $image.''.time().'.'.$extension;
                $newname    =   __DIR__."/uploads/scrnsots/".$image_name;
                $basepath   =   pathinfo($newname,PATHINFO_DIRNAME);
                # Create the folder if not already made
                if(!is_dir($basepath))
                    mkdir($basepath,0755,true);
                # It's more common to use this function here instead of copy()
                if (!move_uploaded_file($_FILES['scrnsots']['tmp_name'], $newname)) {
                    echo '<h1>Copy unsuccessfull!</h1>';
                    $errors=1;
                }
                else {
                    # Have your sizes here
                    $sizes  =   array(
                        array(1366,768),
                        array(1280,600),
                        array(768,1024)
                    );
                    # Loop through your sizes here and apply your function
                    foreach($sizes as $hw) {
                        $thumb_name =   __DIR__.'/uploads/scrnsots/thumb/'.$hw[0].$hw[1].'/thumb-'.$image_name;
                        $thumb_path =   pathinfo($thumb_name,PATHINFO_DIRNAME);
                        # Create the thumbnail directory(s) if not exist
                        if(!is_dir($thumb_path))
                            mkdir($thumb_path,0755,true);
                        # Run your function
                        make_thumb($newname,$thumb_name,$hw[0],$hw[1]);
                    }
                }
            }
        }
    }
}