Image from database into PDF using FPDF - php

Question

I have an image that is sent from an iPad app to an SQL database. I can retrieve this image and display in a web page using the following php:
$img = base64_encode($row['photoData']);
echo "<img src=\"data:image/jpg;charset=utf8;base64, $img\"/>";
This displays fine. What I want to do now is put this image into a PDF document using FPDF however I am struggling to do this.
This:
$img = base64_encode($row['photoData']);
$pdf->Image($img);
give this error:
FPDF error: Image file has no extension and no type was specified:
So I tried this (although I realise I will then have to look at how to get the size of the image sorted):
$pdf->Image($img, 20, 20, 20, 20 'JPG');
which give me:
FPDF error: Missing or incorrect image file:
What is the correct way to do this?
Or would it be easier to temporarily save the image to the server and then place the saved image into the PDFdoc?

Answer 1

As mentioned in the comments above this is possible by using a stream ("data url") to hand over the image data to the fpdf library without writing physical files to disk:
<?php
// load the 'fpdf' extension
require('fpdf.php');
// just for demonstration purpose, the OP gets the content from a database instead
$h_img = fopen('img.jpg', "rb");
$img = fread($h_img, filesize('img.jpg'));
fclose($h_img);
// prepare a base64 encoded "data url"
$pic = 'data://text/plain;base64,' . base64_encode($img);
// extract dimensions from image
$info = getimagesize($pic);
// create a simple pdf document to prove this is very well possible:
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('Arial','B',16);
$pdf->Cell(40,10,'Hello Image!');
$pdf->Image($pic, 10, 30, $info[0], $info[1], 'jpg');
$pdf->Output();
If this is a good advice is another question, this is merely meant to prove that this is possible...

Answer 2

According to the Docs FPDF::Image accepts a filename as the first argument, not a binary blob.
If you want to use FPDF specifically, save the image to a temporary file first, and then pass that to FPDF::Image.
To do that, something like this should work:
$tmpFile = tempnam(sys_get_temp_dir(), 'fpdfimg');
if (file_put_contents($tmpFile, $row['photoData'])) {
$fpdf->Image($tmpFile);
// save/display image
unlink($tmpFile);
}
Alternatively, if you want to just serve the image as a PDF (with no other content) you could use Imagick:
$im = new \Imagick();
$im->readImageBlob($row['photoData']);
$im->setImageFormat('pdf');
header('Content-Type: application/pdf');
echo $im;

Answer 3

Since FPDF cannot use base64 data to produce images on the PDF, I would recommend saving the file to the disk permanently as opposed to writing a temp file for every PDF operation.
This will save you a lot of I/O overhead.
Assuming your table has unique photo_id or photo_name to accompany photoData then you can use something like this to create your images and use them in FPDF.
I will also assume you have a last_update and photo_extension column.
<?php
$path = '/path/to/fpdf/images/';
$filename = $row['photo_id'].'.'.$row['photo_extension'];
$filepath = $path.$filename;
// If a physical file is not available then create it
// If the DB data is fresher than the file then make a new file
if(!is_file($filepath) || strtotime($row['last_update']) > filemtime($filepath))
{
$result = file_put_contents($filepath, $row['photoData']);
if($result === FALSE)
{
die(__FILE__.'<br>Error - Line #'.__LINE__.': Could not create '.$filepath);
}
}
$pdf->Image($filepath);
If you plan on updating the photoData which is stored in your DB then you will have to make sure to also have a timestamp column and compare that timestamp against the filemtime($filepath) of the image on your disk.

Answer 4

Another solution for this ;)
Make a new php by copying and pasting this (piece of fpdf's code edited):
require('fpdf.php');
class DATAIMAGE extends FPDF
{
protected function _parsedata($file)
{
// Extract info from a JPEG file
$a = getimagesizefromstring($file);
if(!$a)
$this->Error('Missing or incorrect image file: '.$file);
if($a[2]!=2)
$this->Error('Not a JPEG file: '.$file);
if(!isset($a['channels']) || $a['channels']==3)
$colspace = 'DeviceRGB';
elseif($a['channels']==4)
$colspace = 'DeviceCMYK';
else
$colspace = 'DeviceGray';
$bpc = isset($a['bits']) ? $a['bits'] : 8;
return array('w'=>$a[0], 'h'=>$a[1], 'cs'=>$colspace, 'bpc'=>$bpc, 'f'=>'DCTDecode', 'data'=>$file);
}
}
Then call this php instead of fpdf.php in your main php.
You'll now be able to display an image simply by adding 'data' to the end of the function:
$pdf->Image($mysqlrow["blob"],0,0,40,0,'data');