image resize and overlay

Anon

Hi,
I'm looking for info on how to take a picture file (jpg), resize it, then overlay a gif image on top of it, and display the final image.

I looked through previous posts and found similar problems so I'm pretty sure this is possible, but I couldn't find anything that would help me. Any help would be great, examples especially.

Thanks

mithril

Image resizing and overlays are indeed possible via the GD module, but not using GIF's. For over a year now, GD has supported only JPEG's, PNG's, and WBMP's (wireless bitmaps). GIF support was dropped due to licensing restrictions and royalty requirements imposed on teh LZW compression algoryhtm by our sic good friends at Unisys. Besides, PNG is better than GIF (very outdated format).... though that may not be much consolation in your situation🙂 HTH.

Geoff A. Virgo

Anon

Alright, how would I do the same thing but using a png instead of the gif?

Thanks

mithril

KGMoney,

It's actually pretty simple, as long as you're using PHP 4.0.6 or higher. With PHP 4.0.5 and eariler, there may be a work about.... but I don't don't it🙂 You just need to use the ImageCreateFromJPEG() and ImageCreateFromPNG() functions to create the image resource identifiers you'll work with. You use the ImageCopyMerged function to copy one of the image resources onto the other. Finally use the ImageJPEG() and ImagePNG() functions to output the merged image in the format you desire. Read the Image Functions section of the PHP manual for more info.

<?php

  // create the image resource identifers
    $img1 = ImageCreateFromJPEG("./base.jpg");
    $img2 = ImageCreateFromPNG("./overlay.png");

  // merge the images, using a 50% opacity in the overlay
    ImageCopyMerge ($img1, $img2, 0, 0, 0, 0, ImageSX($img2), ImageSY($img2), 50);

  // write the new image to disk
    ImagePNG($img1, "./new.png");

  // print the new image to the screen
    echo "<img src=\"./new.png\" border=\"0\" width=\"" . ImageSX($img1) . "\" height=\"" . ImageSX($img1) . "\">\n";

  // destroy the image identifiers
    ImageDestroy($img1);
    ImageDestroy($img2);

HTH.

Geoff A. Virgo

Anon

Hmmm, I'm actually working with PHP 3.0.12 :-( and it's on my ISP's server. Does anyone know how I would go about doing this in version 3?

Thanks Virgo for the help, I'll read up on that and see if I can figure something out for version 3.

mithril

3.0.12? Ouch🙂

In that case you may actaully have a GIF enabled version of GD to play with. The only thing is, the GIF version is mutually exclusive of the JPEG/PNG version and you can't run both at once. Oh ya, you might also want to look into the Unisys royalty thing I mentioned in a earlier post. Unisys is licensing the LZW algorythm to graphic software makers like Adobe, etc. As long as you create your GIF's with a software package that's pain the licensing fee you're alright. If you haven't Unisys has the right to fine you a royalty under US Patent Law for patent infringment. If your ISP has a GIF enabled version beware....... GIF support was dropped from GD because they chose not to pay the license.

Geoff A. Virgo

Anon

I'm using Macromedia Fireworks, I would assume they paid the royalty. Any idea?

Thanks for all the help, you've certainly pointed me in the right direction.

mithril

I think it's probably safe to assume🙂 I'm guessing that all of the major commerical Win32 graphics packages (Photoshop, Fireworks, PaintShop, etc.) have paid.... after all they'd be opening themselves up to huge lawsuits if they haven't. I know The GIMP hasn't and no longer supports GIF "out of the box", although they do have a LZW GIF patch you can download if you affirm you have the legal right (ie. you've paid) to use LZW.

Geoff A. Virgo

Anon

Is there a php script to overlay text on to an image in a desired location and save it as a final jpg/gif?