使用FPDF将数据库中的图像转换为PDF

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

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.