Image Watermarking On Upload

Sharif

Is there a way to watermark an image during file upload with a custom watermark? If so, any one know how? Or have made a function that does that?

drew010

if you create the watermark and save it as its own image file, you can use [man]imagecopyresized[/man] to place the watermark on top of the uploaded image.

Sharif

I don't know if you gave me the wrong function but I don't see how that function can place an image on another at all.

drew010

imagecopyresized() copies a rectangular portion of one image to another image. Dst_im is the destination image, src_im is the source image identifier.

thats from the manual. both images have to be gd resources, but it will put on image on top of the other, and it allows you to specify the new size

Sharif

Thanks, get it now. But there has to be a different way right?

drew010

[man]imagecopymerge[/man]
there arent many other ways with gd.

Sharif

Hey maybe this might work right?

http://www.phpclasses.org/browse/package/1580.html

Anyone use that before?

drew010

yeah by reading the description it seems like its what you want to do.

MrCool

I use this on my website and it works perfectly
It creates your logo on the bottom right, and then saves it.

<?
function watermark($srcfilename, $newname) { 
$watermark="http://www.ellx.net/images/watermark.png";
$quality="100";
$imageInfo = getimagesize($srcfilename); 
$width = $imageInfo[0]; 
$height = $imageInfo[1]; 
$logoinfo = getimagesize($watermark); 
$logowidth = $logoinfo[0]; 
$logoheight = $logoinfo[1]; 
$horizextra =$width - $logowidth; 
$vertextra =$height - $logoheight; 
$horizmargin = round($horizextra / 2); 
$vertmargin = round($vertextra / 2); 
$photoImage = ImageCreateFromJPEG($srcfilename); 
ImageAlphaBlending($photoImage, true); 
$logoImage = ImageCreateFromPNG($watermark); 
$logoW = ImageSX($logoImage); 
$logoH = ImageSY($logoImage); 
ImageCopy($photoImage, $logoImage, ImageSX($photoImage)-$logoW, ImageSY($photoImage)-$logoH, 0, 0, $logoW, $logoH); 
//ImageJPEG($photoImage); // output to browser 
ImageJPEG($photoImage,"./images/uploaded/".$newname, $quality); 
ImageDestroy($photoImage); 
ImageDestroy($logoImage); 
} 
?>

Sharif

Hey MrCool, will that work during an upload process? It seems perfect! Does it reduce the quality of images in anyway? And you're a FS fan too? Awesome, can't wait to get playing again.

MrCool

I use this only for upload, so that i don't store images without the copyright, so there's no possibility of "stealing them". Yeah, i'm not 100% into FS, it's more the others. I can't stay hours doing long flights (i.e. across atlantic), but feel free to register! If u have any questions on the script just ask, I'll do my best (I found that script on the net).

leatherback

Hehe,

Just came in to see whether i could find info on watermarking.. And Voila! The whole script, 5 secs work.

you gotta love this forum!

Thx MrCool!!

Sharif

You wouldn't happen to know of a function that will watermark images when it is displayed would you?

MrCool

You have to make it display from the folder, and then create the file with the watermark. No?...😕

Sharif

Ok so watermark($_FILES['field']['tmp_name']) will work during right?

MrCool

The script I gave you above only creates a file with a watermark. You might have to change it and use that line that was commented out. One thing is for sure, the script how it is now won't work for what you are trying to achieve...

Sharif

I thought you used that function to apply a watermark to images when you upload. That is what I am trying to do.

MrCool

Originally posted by Sharif
You wouldn't happen to know of a function that will watermark images when it is displayed would you?

Here you say when it's displayed, did you mean to create images w/ watermark when you upload them? That's the function of that script i posted.

Sharif

Well what I am trying to do is when I upload an image, a watermark will be applied to it during the process so the image has copyright on it, and then store it on my server. I thought that is what you were doing.

Weedpacket

Given that you want to add a watermark to an image every time the image is output (maybe the watermark has some sort of time-dependent feature to it?) ... well, the process is exactly the same as adding a watermark to an image when it's uploaded. The only differences are that the source image is stored on the server instead of being supplied in a form, and the output is sent out to the browser instead of to a file on the server.

The only difference in MrCool's code is that it needs a header() statement (to tell the browser that what's about to follow is a JPEG image), and to drop the filename that the image is to be saved to in [man]ImageJPEG/man.

Obviously, the script that ouputs the image can't be outputting anything else - that would corrupt the JPEG data.

Another change would be to use a filename as the location of the "watermark" image. Using a URL is just silly.