PHP-获取base64 img字符串解码并另存为jpg（结果为空白图片）

Z时代
2024-01-10
分类：问答

嗨，我实际上是通过ajax将base64图像字符串通过ajax发送到php脚本，该脚本仅解码字符串并将内容另存为.jpg文件。

但是结果是空白图像。

这怎么可能？

php脚本：

$uploadedPhotos = array('photo_1','photo_2','photo_3','photo_4');
            foreach ($uploadedPhotos as $file) {
                if($this->input->post('photo_1')){
                     $photoTemp = base64_decode($this->input->post('photo_1'));
                    /*Set name of the photo for show in the form*/
                    $this->session->set_userdata('upload_'.$file,'ant');
                    /*set time of the upload*/
                    if(!$this->session->userdata('uploading_on_datetime')){
                     $this->session->set_userdata('uploading_on_datetime',time());
                    }
                     $datetime_upload = $this->session->userdata('uploading_on_datetime',true);
                    /*create temp dir with time and user id*/
                    $new_dir = 'temp/user_'.$this->session->userdata('user_id',true).'_on_'.$datetime_upload.'/';
                    @mkdir($new_dir);
                    /*move uploaded file with new name*/
                    @file_put_contents( $new_dir.$file.'.jpg',$photoTemp);
            }

对于ajax来说可以，因为echo $ photoTemp返回字符串。

我尝试过var_dump(@file_put_contents(

$new_dir.$file.'.jpg',$photoTemp));并且它返回，bool(true)因为保存了图像，但是图像中没有内容:(空图像

对于空图像，我的意思是说，文件已创建并命名，并且它具有与传递给php的内容相同的大小，但是当我尝试打开该图像进行预览时，它说，由于损坏或文件损坏而无法打开文件类型格式

无论如何，这是将照片作为base64并将其发送到php的JS：

<script type="text/javascript">
var _min_width = 470;
var _min_height = 330;
var _which;
var _fyle_type;
var  io;
var allowed_types = new Array('image/png','image/jpg','image/jpeg');
if (typeof(FileReader) === 'function'){
$('input[type="file"]').on('change', function(e) {
    var _file_name = $(this).val();
    $('.'+_which+'_holder').text(_file_name);
    var file = e.target.files[0];
    if (!in_array(file.type,allowed_types) || file.length === 0){
        notify("You must select a valid image file!",false,false); 
        return;
    }
    if(file.size > 3145728 /*3MB*/){
        notify("<?php echo lang('each-photo-1MB'); ?>",false,false); 
        return;
    }
    notify_destroy();
    var reader = new FileReader();
    reader.onload = fileOnload;
  reader.readAsDataURL(file);
});
function fileOnload(e) {
    var img = document.createElement('img');
    img.src = e.target.result;
    img.addEventListener('load', function() {
        if(img.width < _min_width || img.height < _min_height ){
        notify("<?php echo lang('each-photo-1MB'); ?>",false,false); 
        return;
        }
        $.ajax({
            type:'post',
            dataType:'script',
            data:{photo_1:e.target.result},
            url:_config_base_url+'/upload/upload_photos',
            progress:function(e){
                console.log(e);
            },
            success:function(d){
                $('body').append('<img src="'+d+'"/>');
            }
         });
    });
}
}
</script>

回答：

AFAIK，您必须使用图像函数imagecreatefromstring，imagejpeg创建图像。

$imageData = base64_decode($imageData);
$source = imagecreatefromstring($imageData);
$rotate = imagerotate($source, $angle, 0); // if want to rotate the image
$imageSave = imagejpeg($rotate,$imageName,100);
imagedestroy($source);

希望这会有所帮助。

PHP CODE WITH IMAGE DATA

$imageDataEncoded = base64_encode(file_get_contents('sample.png'));
$imageData = base64_decode($imageDataEncoded);
$source = imagecreatefromstring($imageData);
$angle = 90;
$rotate = imagerotate($source, $angle, 0); // if want to rotate the image
$imageName = "hello1.png";
$imageSave = imagejpeg($rotate,$imageName,100);
imagedestroy($source);

因此，以下是程序的php部分.. NOTE带注释的更改Change is here

    $uploadedPhotos = array('photo_1','photo_2','photo_3','photo_4');
     foreach ($uploadedPhotos as $file) {
      if($this->input->post($file)){                   
         $imageData = base64_decode($this->input->post($file)); // <-- **Change is here for variable name only**
         $photo = imagecreatefromstring($imageData); // <-- **Change is here**
        /* Set name of the photo for show in the form */
        $this->session->set_userdata('upload_'.$file,'ant');
        /*set time of the upload*/
        if(!$this->session->userdata('uploading_on_datetime')){
         $this->session->set_userdata('uploading_on_datetime',time());
        }
         $datetime_upload = $this->session->userdata('uploading_on_datetime',true);
        /* create temp dir with time and user id */
        $new_dir = 'temp/user_'.$this->session->userdata('user_id',true).'_on_'.$datetime_upload.'/';
        if(!is_dir($new_dir)){
        @mkdir($new_dir);
        }
        /* move uploaded file with new name */
        // @file_put_contents( $new_dir.$file.'.jpg',imagejpeg($photo));
        imagejpeg($photo,$new_dir.$file.'.jpg',100); // <-- **Change is here**
      }
    }