Coverting Hex to Image in PHP? - php

I am developing mobile app which talks with server via PHP Webservice. This is my first time using PHP. I managed to upload data in to database. Now i need to send an image to store it in ftp server. For that i converted image->hex and sent from my app.
Server Side
I got the hex code but not sure how to convert it in to an image and store in in ftp server. I am really struggling here. I googled it but couldn't find exact one.
Any help is much appreciated.

Convert the HEX string to binary:
$binary = pack("H*", $hex);
pack("H*", ...) is equivalent to hex2bin, which is available since PHP 5.4.
Write it to disk:
file_put_contents("file.png", $binary);

Suppose you have received a hex string in a page where you want to convert this hex to real image. Please check this code snippet will help you or not.
<?php
$hexpic=".......................
.....................";
# convert the hex string to binary
$data = pack("H" . strlen($hexpic), $hexpic);
#write the binary string into an image file
file_put_contents("sample.png", $data);
?>

Related

How to convert base64 string to video in PHP?

I have a base64 encoded string which my frontend team has provided me with.The string is a video which was encoded using base64. I want to convert that back into a video file using Php.
I am currently just using the following to decode the string but I don't know how to proceed further.
$decoded = base64_decode ($encoded_string);
There seems to be a way to convert images from string using imagecreatefromstring() function, but I could not find a way to convert it into a video.
Thank you
you should know the video file type. you can decode to original format
$fp=file_put_contents('sample.mp4',base64_decode($encoded_string,true));
Video streams tend to be very large so is isn't a good idea to convert them to plain text in the first place. We'd also need to know the exact mechanism (protocol, format...) used to deliver the base64 string. In any case, once there you can do something like this (error checking omitted for brevity):
$chunk_size = 8192; // Bytes (must be multiple of 4)
$input = fopen('php://input', 'rb');
$output = fopen('/tmp/foo.avi', 'wb');
while ($chunk = fread($input, $chunk_size)) {
fwrite($output, base64_decode($chunk));
}
fclose($output);
fclose($input);
Smaller chunks reduce RAM usage and larger chunks improve I/O performance. You'll need to find a balance that works best for you.

PHP base64 encoded image not displaying correctly

I'm trying to send an image (any size) over to an API I'm creating, using base64 encoding. The encoded string hits my API as a parameter in the URL. The API built with PHP.
Once the request hits my API, I want to store the image onto my server, and save the file name in the database. This is working, however I'm getting some odd outputs with the actual image.
For reference, I also followed http://blog.justin.kelly.org.au/simple-base64-encodedecode-url-safe-functions/ but have the same results.
The image I am trying to store on my server:
$encode = base64_encode(file_get_contents($image));
echo $encode;
For testing, the ouput of this is the string I'm using to pass to my API.
In the API:
$image = base64_decode($_POST['image']));
$image_name = md5($image) . ".jpg";
file_put_contents(/public/image/ . $image_name, $image);
This works, my image is put onto the server in the correct directory with a random name which is saved to the database.
However, when navigating to the image directly, the image is warped:
If you have a sharp eye, the top part of the image is actually correct before it starts to fail, which makes me start to think whether the string is not getting encoded correctly to be sent as a parameter?
Any clues would be lovely, cheers.
EDIT: Changed it to POST, removed urlencode/decode & removed strtr.
Thanks to the comments:
base64_encode(file_get_contents($image_path));
No urlencode or strtr needed. Use POST request, and alter the post_max_size on the web server to allow for bigger images to be passed through.
$image = base64_decode($this->getParameters('avatar'));
$image_name = md5($image) . ".jpg";
Maybe I'm looking at it wrong, but first you encode it base64 -> urlencode and then you decode it base64 -> urldecode again, shouldn't the latter be in reverse order?

Reading binary file in php and converting it into string

I spent almost a day for this , but did not get success.
What i want to do is, i have a binary file "data.dat"
I want to read the file contents and output it in text format in say "data.txt" in php.
I tried unpack function of php, but requires the type to be mentioned as the first argument(May be i am wrong, new to php).
$data = fread($file, 4); // 4 is the byte size of a whole on a 32-bit PC.
$content= unpack("C", $data); //C for unsigned charecter , i for int and so on...
But what if i dont know that at what place , what type of data is stored in the file that i am reading?
This function is restricting me because of the type.
I want something similar to this
$content= unpack("s", $data); //where s can denote to string
Thanks.
PHP does not have a "binary" type. Binary data is stored in strings. If you read binary data from a file, it's already stored as a string. You do not need to convert it into a string.
If the binary data already represents text in some standard encoding, you don't need to do anything as you already have a valid string. If the binary data represents some encoding, you need to know what you need to do with it, we don't know.

How to save a base64 decoded image in the filesystem using php?

I am getting a base64 encoded JPEG string via a POST request to my web service.
I want to decode it and save it in the filesystem.
How can I achieve this using PHP 5.3.
I am able to successfully decode the data using the base64_decode function.
How can I save this decoded string as a JPEG image in the server?
Thanks in advance.
If you are sure the image will always be jpg then you can simply use: file_put_contents();
<?php
$decoded=base64_decode($encodedString);
file_put_contents('newImage.JPG',$decoded);
//leave it to you to randomize the filename.
?>
Replacing the blank spaces with + signs is required if the data is derived from canvas.toDataURL() function.
$encodedString = str_replace(' ','+',$encodedString);
See this question
It helped a lot in my case.

convert image to byte array

i want convert image into byte array in php.actually i am accessing web service in dot net.where i want to pass image as byte array.i tried this code
$data1 = file_get_contents("upload/1311677409gen1.jpg");
$byteArr1 = str_split($data1);
foreach ($byteArr1 as $key=>$val)
{
$byteArr1[$key] = ord($val);
}
and send this array name to web service.but i got error parameter is not valid.i googled it.but dont get proper solution.i need it urgent.help.
Thanks in advance.
Without seeing the .net webservice, you probably have two options:
Stream the image
base64 encode the image before transfer, provided the webservice can decode it.

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