Run php script behaving like image - php

There is a way I write eg. http://www.examle.com/hello/image.png (or in another form, it doesn't matter) and get image with text "hello" in it?
I mean, how to run some php script when loading image (create image "on the fly", no caching) and be able to use it like ordinary image so I can embed it somewhere and everytime the page with image is loaded it loads image with current numbers/stats, whatever.
Something like this banner:
http://cache.www.gametracker.com/server_info/201.4.55.227:29009/b_560_95_1.png
return this:
Can someone give me a hint how to do that?
EDIT:
I know how to create image, but issue is how to update it (recreate it) when is loaded on website. I need image actually provide "live" data.
One way would be probably using cron jobs and update image "outside" every period of time, in case the name remain same, it would do the trick, although it's not live.

You could use PHP GD: http://www.php.net/manual/en/book.image.php
Example (from http://www.php.net/manual/en/image.examples-png.php):
<?php
header("Content-type: image/png");
$string = $_GET['text'];
$im = imagecreatefrompng("images/button1.png");
$orange = imagecolorallocate($im, 220, 210, 60);
$px = (imagesx($im) - 7.5 * strlen($string)) / 2;
imagestring($im, 3, $px, 9, $string, $orange);
imagepng($im);
imagedestroy($im);
?>
The docs should point you in the right direction.

Related

Don't show processed GD PHP image in browser

this is my first question and I'm planning to hang around in this forum. I'm very new to programming since I'm studying but I'm making great progress. So, with this in mind I'll try to be as detailed as possible.
The project I am working with is about creating a png-image using GD PHP. The script recieves data, calculates image WIDTH/HEIGHT according to these. From this data I then print out pixels on the image in different spots. Everything works great, it displays the image and saves it on the server, there's nothing wrong with that. But when I run the script, it outputs the image to the browser. I don't want that. I just want the script to process the image and save it to the server. I have searched plenty but haven't found anything about it.
Code for creating the image: I have to remove some code though, but it's not needed to answer my question. I suspect it's something with the header and imagecreatetruecolor. This is all the data I can give.
<?php
//Some calculations before
// --- START: CREATE IMAGE ---
$png = imagecreatetruecolor($WIDTH, $HEIGHT);
imagesavealpha($png, true);
$trans_colour = imagecolorallocatealpha($png, 0, 0, 0, 127);
imagefill($png, 0, 0, $trans_colour);
//Here's just a loop to print pixels
header("Content-type: image/png");
imagepng($png);
save($png); //Function used for saving
//Erase from memory
imagedestroy($png);
?>

How to put a watermark text across the whole image in diagonal position?

I have connected my Google Drive with my website and im getting images in this format: https://googledrive.com/host/{$GoogleID}. What i want to do is to add a text (not image) watermark to all the images im getting from Google Drive. I already tried with:
http://php.net/manual/en/image.examples.merged-watermark.php
http://phpimageworkshop.com/tutorial/1/adding-watermark.html
Both of them dosent work for me or i cant get them to work i dont know why. I will give an example for an image url: https://googledrive.com/host/0B9eVkF94eohMRlBQVENRWE5mc2c
I have also tried the code from this answer, but it dosent work as well. I guess the problem should be that the files i'm getting from Google Drive are not with the file extention and maybe this cause the problem. This is only my guess...
UPDATE:
i managed to show the photo on the website, but how to put the text in diagonal possition across all the photo like this
try to read image with file_get_contents or fopen and create image from string.
$im = imagecreatefromstring(file_get_contents("image url"));
and then use this example: http://php.net/manual/en/image.examples.merged-watermark.php
Thanks to #Durim Jusaj for helping me out with this one and finally i got the answer after a lot of searching and dealing with a lot of problems i will share my knowledge with u guys. So i will post the code and i will explain what is the code doing.
First thing first. Include this function in your file. This function is finding the center of the image. I havent wrote it i found it in the php docs under the comments so maybe it can be done without it or this function can be modified to be better written.
function imagettftext_cr(&$im, $size, $angle, $x, $y, $color, $fontfile, $text)
{
// retrieve boundingbox
$bbox = imagettfbbox($size, $angle, $fontfile, $text);
// calculate deviation
$dx = ($bbox[2]-$bbox[0])/2.0 - ($bbox[2]-$bbox[4])/2.0; // deviation left-right
$dy = ($bbox[3]-$bbox[1])/2.0 + ($bbox[7]-$bbox[1])/2.0; // deviation top-bottom
// new pivotpoint
$px = $x-$dx;
$py = $y-$dy;
return imagettftext($im, $size, $angle, $px, $py, $color, $fontfile, $text);
}
Load the image you want to apply the watermark to. I'm using Google Drive to extract my photos so thats why im using the file_get_contents, if you are the case like mine then use this, BUT otherwise use what is common and if your picture have extension like .jpg or .png you can use imagecreatefromjpeg or imagecreatefrompng. So it should be something like that $im = imagecreatefromjpeg('photo.jpeg'); for example.
$im = imagecreatefromstring(file_get_contents("https://drive.google.com/uc?id=" . $v['GoogleID']));
After that we need to calculate the position of watermark so we want the watermark to be in the center and to auto adjust its size based on the size of the photo. So on the first like we store all the attributes of the image to array. Second and third lines we calculate where is the center of the image (for me dividing it by 2.2 worked great, you can change this if u want to adjust the position. Last line is the size of the watermark according to the size of the image. This is very important as the watermark will be small or very big if u have images with different sizes.
list($width, $height, $type, $attr) = getimagesize("https://drive.google.com/uc?id=" . $v['GoogleID']);
$width = $width / 2.2;
$height = $height / 2.2;
$size = ($width + $height) / 4;
Set the content-type
header('Content-Type: image/png');
Create the image. I dont know why it should be done twice, but im following the php manual.
$im = imagecreatefromstring(file_get_contents("https://drive.google.com/uc?id=" . $v['GoogleID']));
Create some colors. So, if you want your watermark to be transparent (like mine) you have to use imagecolorallocatealpha, otherwise use imagecolorallocate. Last parameter is the transparency. You can google every function name for more info from the php doc.
$black = imagecolorallocatealpha($im, 0, 0, 0, 100);
The text to draw. Simple as that. Write what you want your text to be.
$text = 'nima.bg';
Replace path by your own font path. Put a font in your server so the code can take it (if you dont have already).
$font = 'fonts/ParsekCyrillic.ttf';
Adding all together. Basically you are creating the final image with the water mark with this function. The magic ;)
imagettftext_cr($im, $size, 20, $width, $height, $black, $font, $text);
Now this is the tricky part! If you want to just display the image without saving it to your server you can simply copy and paste this code, but the website will load very slow if you have more then 2-3 images. So, what i suggest you to do it to save the final images to your server and then display it. I know you will have duplicates, but this is the best choice i think.
ob_start();
imagepng($im);
$image = ob_get_contents();
ob_end_clean();
imagedestroy($im);
echo "<img src='data:image/png;base64," . base64_encode($image) . "'>";
}
OR you can save the images to your server and then display them which is much much faster. The best thing you can do is to process all the images create them with the watermark and then display them (so you have them ready to be show when a visitor visit your website).
imagepng($im, 'photo_stamp.png');
imagedestroy($im);
And the final result for me was that.
UPDATE: As of 2017 you can extract the image using this link 'https://drive.google.com/uc?id=(GoogleID)' or you can just use the 'webContentLink' property of the Google_DriveFile Object (it will give you the same link).

Create image, then pass it back

I'm fairly new to php but I'm trying to send an image to a buffer or some sort of temporary place where I can access later. The script I'm calling merges a bunch of images into one, then displays that image (see it in action here - change query parameters to change image). Here's a piece of my code so you have an idea of how that's happening:
$dest = imagecreatefrompng($img0);
$src12 = imagecreatefrompng($img12);
imagecolortransparent($src12, imagecolorat($src12, 0, 0));
//copy and merge
$src12_x = imagesx($src12);
$src12_y = imagesy($src12);
imagecopymerge($dest, $src12, 0, 0, 0, 0, $src12_x, $src12_y, 100);
// Output and free from memory
header('Content-Type: image/png');
imagepng($dest);
imagedestroy($dest);
imagedestroy($src);
However, this is an external script so I'd like to be able to pull that image from another page. I'm not sure what the best way to do it is... temporarily store it or pass the image back through. The one constraint is that the image has to exist before the content of the parent page is loaded. How can I make this happen?
If I understand correctly what you mean;
1) You want to pull the image from another website and save it to disk, you can do this;
file_put_contents("img.png", file_get_contents("URL-TO-IMAGE"));
2) You want to just display it? As the URL aboves headers are to display an image, you can put it right into an IMG tag.
<img src="URL-TO-IMAGE">

Save HTML table as an image

I have a website I am building that takes data (the person's name) from a form and posts it into a customized "note" in a table on the next page. I want the user to then be able to save their "note" as an image with their customized name on it. Is there a way to save a SPECIFIC HTML TABLE as a PNG? Maybe take a screenshot of a specific coordinate on a web page?
If not is there a way to render posted PHP content from the form in an HTML canvas?
Any help would be great. I'm in a little over my head right now.
While you can render HTML using a variety of tools, you can't be sure that those tools will render the HTML the same way your browser renders it.
If your end goal is to generate an image with text on it, then let's solve that problem instead of trying to make the solution you suggested work.
Have a look at PHP's imagettftext() function. It contains an Example #1 which creates a small, simple image from text that can be stored in any variable ... including a form variable.
By using this example, and adding a few other of PHP's GD functions, you can make a decent replica of a table, and make sure it looks exactly the way you want it, rather than the way html2ps or some other tool renders it.
<?php
// Set the content-type
header('Content-Type: image/png');
// Create the image
$im = imagecreatetruecolor(400, 30);
// Create some colors
$white = imagecolorallocate($im, 255, 255, 255);
$grey = imagecolorallocate($im, 128, 128, 128);
$black = imagecolorallocate($im, 0, 0, 0);
imagefilledrectangle($im, 0, 0, 399, 29, $white);
// The text to draw
$text = isset($_POST['name']) ? $_POST['name'] : "name";
// Replace path by your own font path
$font = 'arial.ttf';
// Add some shadow to the text
imagettftext($im, 20, 0, 11, 21, $grey, $font, $text);
// Add the text
imagettftext($im, 20, 0, 10, 20, $black, $font, $text);
// Using imagepng() results in clearer text compared with imagejpeg()
imagepng($im);
imagedestroy($im);
?>
Here's sample output generated by the above script:
Note that you'll need to provide arial.ttf per the instructions at the link above.
If things don't work, look for errors both on-screen and in your web server's error log FIRST, before following up here. It's possible that PHP's GD module is not installed on your web server. If this is the case, you should check with your server administrator to make sure what you need is available to you.
You can try this JS library on client side.
workable solution
use fpdf to create pdf from html (table)
use imagemagick to convert pdf to png
You can also use Xvfb. It's a linux package. It stands for "X-window Virtual Frame Buffer" (if you were wondering why on earth it had such an esoteric name).
What that will do, is load a page, execute any JavaScript and apply the different stylings from CSS, all in the frame-buffer of the server. Then you can save the image.
Xvfb will probably not be available on most shared-hosting services, however, if that doesn't matter, then it would be a viable solution.
You can use something like html2ps

Trouble passing variable from page to page using $_SESSION php

I am doing an assignment for school where we are to make two php files. First file invokes session, generates a random 5 char string, and saves the string to the session array. The second script generates an image, and takes the string from the first file and incorporates it over the image to make a captcha.
I am having an issue passing the value to the second script. The session variable 'captcha_string' is fully visible in the first script, but is not passed to the second page. I am brand new at this, and frustrated. My understanding is, that as long as I start session, the entire $_SESSION array should be available. When I run the first script, I get a broken image tag, not the captcha i am hoping for. Hope this clears up my problem.
This is what I have done for the first file:
<?php
session_start();
$possible_chars = array_merge(range('A','Z'),range('0','9'));
shuffle($possible_chars);
$string = substr(implode($possible_chars),0,5);
$_SESSION['captcha_string']=$string;
?>
<img src="captcha_generator.php" alt="Weinerdog!" />
and this is the bit from the second file where I try to grab the $string (captcha_string), which is named "captcha_generator.php:
<?php
session_start();
putenv('GDFONTPATH=' . realpath('.'));
header("Content-type: image/png");
//import string for the captcha from $_SESSION
$string = $_SESSION['captcha_string'];
// Build an image resource using an existing image as a starting point.
$backgroundimage = "captcha_wiener.jpg";
$im=imagecreatefromjpeg($backgroundimage);
$colour = imagecolorallocate($im, rand(0,255), rand(0,255), rand(0,255));
// Output the string of characters using a true type font.
// Above we set the font path to the current directory, this
// means that arial.ttf font file must be in this directory.
$font = 'arial.ttf';
$angle = rand(-5,5);
imagettftext($im, 120, $angle, 50, 250, $colour, $font, $string);
// Draw some annoying lines across the image.
imagesetthickness($im, 10);
for ($i = 0; $i <3; $i++) {
imageline($im, rand(100,50), rand(150,200), rand(450,550), rand(200,250), $colour);
}
// Output the image as a PNG and the free the used memory.
imagejpeg($im);
imagedestroy($im);
?>
This is, of course, strictly an exercise to make sure we can pass values using session. There is no problem with the rest of the code making the captcha, it has been tested and works.
You're echo-ing some values with a content-type set to image/png, hence either you'll have the error of headers already sent, or, if the text wasn't sent yet (because cached by PHP), you'll have a broken image and you won't be able to see the text.
Don't worry, it has happened to everyone including me :-)

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