how to handle GIF images with GD 1.6?

marcnyc

Hello, I have GD 1.6.
Does anybody know if there is any way to handle a GIF image? Is there a way to convert them into JPG's or PNG's so that I can still apply resizing and stuff that I can't do on a GIF image on GD 1.6?

John_Canyon

http://www.php.net/manual/en/ref.image.php

Good place to start. I believe you should find everything
you need to start manipulating .gif images.

God Bless the manual.

Cheers.

marcnyc

You know, you'll be surprised to know that there actually ARE users who read the manual before they post and who post for a reason, not just because they are crazy or lazy.
In my post I have specifically stated that I have version 1.6 (precisely 1.6.2) and if you go to imagecreatefromgif you will see that it says:

Note:
Since all GIF support was removed from the GD library in version 1.6, this function is not available if you are using that version of the GD library.

And THAT is why I posted this message!

John_Canyon

There is an alternative to GD.

Have you checked out,
http://www.imagemagick.org

I have not used it myself, I have been able to manage
using .png and .jpg's with GD, however i hear the results
are quite nice.

Cheers.

marcnyc

see that's the kind of answer you could have given me the first time ;-)

well, I heard about it but never used it.

my problem is that I am on a host and I cannot install these things. I need something that I can use on my host without expecting my host to update or install libraries. If I had that choice I'd just ask them to upgrade to GD2, but they won't.

That is why I was asking if there is any way to sample/open a GIF image and or convert it into a JPEG from within the environment I am in...

marcnyc

so is that it? am I supposed to give up? is there no way at all that with my GD I can resize a GIF image at all? Is there no way to convert it into a PNG or JPG and go from there? is there a way to sample it or just copy whatever is there and put it inside a file with JPEG headers? I don't know I am stumbling in the dark about this... There are soooo many GIF images out there on the internet and so little PNG that I really need to make my script compatible with GIF on this GD 1.6 system I have...

jerdo

I think you answered your question in your second post, GIF support is gone in GD. If you want to try messing with GIFs you either need to get an old version of GD, use a different set of libraries, or come up with your own.

Sxooter

Just bulk convert all your gifs to pngs and then use them. If IE ever gets around to implementing transaparencies in png, you're done.

Or, have your users use a better browser like Mozilla or Opera and then you can use pngs in place of anything except animated gifs, since mngs aren't implemented anyway yet in a browser that I know of.

Mordecai

Using a GIF is just like using a PNG, JPEG, etc. You just need the older version of GD (which you have). Use imagecopyresized() to resize. You can use the Leonardo Image Functions Library I wrote to resize images. It has the lovely imagezoom() function. You might get unexpected results on that version of GD, however.

By the way, do you have licensing rights for using GIF?

marcnyc

Mordecai, besides the fact that PNG colors quality sucks (check out my other post, my understanding is that even if I wanted I can't use imagecopyresized() with a GIF image I can't use it because GD 1.6 doesn't support GIF. Is this correct or can I still use imagecopyresized() with a GIF?

Also, Mordecai, I can't install any new libraries because I am on a shared virtual hosting plan.

Sxooter, in my script everything has to happen on-line for the user using the script, so when you say "just bulk convert" do you imply that you know how to do this online via PHP or did you simply mean that the conversion should be done by me or the user offline with a graphic software?

Mordecai

It's not a library you add to PHP, it's just a file you include.

As far as I know, you can use imagecopyresized works on GIFs. I don't see why it wouldn't, unless it was added after GIF support was removed.

Also, PNG colors are better than GIF's.

marcnyc

Hey Mordecai, I'll make sure to try imagecopyresized() and see if it works with GIF on GD 1.6, but I just assumed it wouldn't since the manual says all support for GIF has been removed in that version and on...

Anyway, your library seems very cool and useful.
I don't see something that looks like a resizing function.
I see the imagezoom() function, therefore I need to ask you, does this function simply make an image "look" smaller or does it actually make a new file out of the image which will "be" smaller (both in width/height and file size)?

Mordecai

It takes an image stream and shrinks it down by the ratio you specify. The image stream is then updated with the smaller version, which can be edited further using GD. If you look at the example, you can see what it does.

marcnyc

I have one question for you... Does your library work on remote images? In other words can I feed your script an url so that it can generate a smaller image from a remotely located image and store it on my local server?

Mordecai

Yes, as long as you put that remote image into a GD stream using imagecreatefrom<format>().

feldon23

marc,

Looking at the other thread, it is bizarre to try to use PNG to do JPEG's job for it.

Similarly, saying you'll convert GIFs to JPEGs is also very strange.

JPEG = photos
GIF/PNG (8 bit) = solid colors/logos/thumbnails

And PNG 8 bit does support 1 bit transparency just like GIF in Internet Explorer. IE does not support 2-8 bits of alpha though. So there is no reason you can't use PNG as a drop-in replacement for GIF.

Since PNG has no viable compression of photographs I am always shocked when people mention using it in lieu of JPEG.

marcnyc

I am not exactly sure what you mean.
I just wanted to convert gifs into png or jpeg because I have gd 1.6 which doesn't support gif, so if there is a way I can use the user submitted gif images then I want to be able to do it, you know what I mean?

Sxooter

the gimp and image magick both can do this. The gimp can be run in a batch mode, by the way. Most folks don't know that.

marcnyc

Originally posted by Mordecai
Yes, as long as you put that remote image into a GD stream using imagecreatefrom<format>().

Mordecai, I am afraid your suggestion doesn't work...

I have this image http://chaindlk.free.fr/big.jpg

I first zoomed in and out of it locally by changing the int x1, int y1, int x2, int y2 variables to 0,0,1600,1200 and by changing imagecreatefromPNG and imagePNG into imagecreatefromJPEG and imageJEPG. It worked PERFECTLY locally but as soon as I put the image on the server and tried to run the script locally I got the following errors (any ideas???):

Warning: imagecreatefromjpeg: Unable to open 'http://chaindlk.free.fr/big.jpg' for reading in D:\WWW\chaindlk.com\httpdocs\leonardo\Examples\imagezoom.php on line 20

Warning: Supplied argument is not a valid Image resource in D:\WWW\chaindlk.com\httpdocs\leonardo\Examples\imagezoom.php on line 21

Warning: Supplied argument is not a valid Image resource in D:\WWW\chaindlk.com\httpdocs\leonardo\imagefunctions.php on line 89

Warning: Supplied argument is not a valid Image resource in D:\WWW\chaindlk.com\httpdocs\leonardo\imagefunctions.php on line 90
ÿØÿàJFIFÿþ>CREATOR: gd-jpeg v1.0 (using IJG JPEG v62), default quality ÿÛC $.' ",#(7),01444'9=82<.342ÿÛC 2!!22222222222222222222222222222222222222222222222222ÿÀhà"ÿÄ ÿÄµ}!1AQa"q2‘¡#B±ÁRÑð$3br‚ %&'()456789:CDEFGHIJSTUVWXYZcdefghijstuvwxyzƒ„…†‡ˆ‰Š’“”•–—˜™š¢£¤¥¦§¨©ª²³´µ¶·¸¹ºÂÃÄÅÆÇÈÉÊÒÓÔÕÖ×ØÙÚáâãäåæçèéêñòóôõö÷øùúÿÄ ÿÄµw!1AQaq"2B‘¡±Á #3RðbrÑ $4á%ñ&'()56789:CDEFGHIJSTUVWXYZcdefghijstuvwxyz‚ƒ„…†‡ˆ‰Š’“”•–—˜™š¢£¤¥¦§¨©ª²³´µ¶·¸¹ºÂÃÄÅÆÇÈÉÊÒÓÔÕÖ×ØÙÚâãäåæçèéêòóôõö÷øùúÿÚ ?ùþŠ( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( Š( ÿÙ

marcnyc

Originally posted by Sxooter
the gimp and image magick both can do this. The gimp can be run in a batch mode, by the way. Most folks don't know that.

What is a batch mode? Does this mean I can run it without asking my host to install anything or change anything???