Problems with image manipulation

[Tanis]

So far i've got:

<?$width = 20;$height = 20;$text=$_GET["text"];for ($i = 0; $i < strlen($text); ++$i){$letter = $text{$i};$filename = "/goodies/letters/$letter.gif";$x = $width-20;$im = imagecreatetruecolor($width, 20);$image = imagecreatefromGIF($filename);imagecopyresampled($im, $image, $x, 0, 0, 0, $width, 20, 20, 20);$width = $width+20;}header('Content-type: image/gif');imageGIF($im);imageDestroy($im);?>

But to no avail...All I get is a big black box (good thing is that it changes by 20 pixels for every letter you have)PS- Each source image is 20x20.View- clickyI tried removing

$im = imagecreatetruecolor($width, 20);

but that just returned http://www.habbground.com/txtst.php?text=ABCDE

[justsomeguy]

$width should always be 20, you want to copy it into a 20x20 block, not a bigger block, and $x should increment by 20 each time.

[Tanis]

But in imagecopyresampled, $width is in the destniation image width spot, so wouldn't you want the width of the destination img increase by 20 for each additional letter?

[justsomeguy]

The destination width is the width of the image when you put it in the new image. If you move a 20x20 image and say the width is 40, the width of the copied image will be 40x20, not 20x20, it will stretch the image. The imagecopyresampled function is usually used to resize an image, and that is how you do it. You don't need to resize, you just want to copy. So width and height stay the same, y doesn't need to change, you just need to keep sliding x down.

[Tanis]

Alright, changed it to

<?0 = $x;$text=$_GET["text"];for ($i = 0; $i < strlen($text); ++$i){$letter = $text{$i};$filename = "/goodies/letters/$letter.gif";$im = imagecreatetruecolor(20, 20);$image = imagecreatefromGIF($filename);imagecopyresampled($im, $image, $x, 0, 0, 0, 20, 20, 20, 20);$x = $x+20;}header('Content-type: image/gif');imageGIF($im);imageDestroy($im);?>

and it doesn't output anything.What am I missing (most likely something really obvious)?

[Mr_CHISOL]

Firtst: You are creating the image(s) in every loop (a new image in every loop), I would put his above the loop (and remove it from the loop):

$im = imagecreatetruecolor( 20*strlen($text), 20 );

Don't forget to destroy $image in the end of each loop (as you create a new every time)Than you might have a problem with GIF-transparancy, nut sure on how to solve that though...Last: I think this line is wrong:

0 = $x;

It's backwardsHope that helped..Good Luck and Don't Panic!

[Tanis]

hehe, backwards it is...Well now that those two things are fixed, all I'm getting is a black box...http://www.habbground.com/txtst.php?text=ABCDE

[justsomeguy]

Change this:$letter = $text{$i};To this:$letter = $text[$i];You might also want to use the absolute path to the gif file instead of a relative path.If that doesn't work, post the full code.

[Tanis]

Works now, but how do i change the background color so its transparent instead of black?

[Mr_CHISOL]

Take a look at this: http://php.net/manual/en/function.imagecre...color.php#66448

[Tanis]

I know WHY its black, i just need to know how to change it.Although it would be ok if the user could simply input a background color (in hex), it would be much better if there was a way to make the image transparent.

[justsomeguy]

That comment that Mr Chisol links to explains how to make an image where the background is initially transparent, but that will only work if you are creating a PNG. JPEG images don't support transparency at all, and GIF images need paletted transparency, not alpha transparency. It will probably be better to output a PNG anyway instead of a GIF or JPG.

[Tanis]

<?$x = 0;$text=$_GET["text"];$im = imagecreatetruecolor( 20*strlen($text), 20 );for ($i = 0; $i < strlen($text); ++$i){$letter = $text[$i];$filename = "http://www.habbground.com/goodies/letters/$letter.png";$image = imagecreatefromPNG($filename);imagecopyresampled($im, $image, $x, 0, 0, 0, 20, 20, 20, 20);$x = $x+20;}header('Content-type: image/png');imagePNG($im);imageDestroy($im);?>

Returns a totally black image (varying in size depending on the # of letters inputted).

[justsomeguy]

I'm not sure if you can use an HTTP path for the imagecreate functions. Try using the local filesystem path instead of a web path. Also, while you're debugging this, remove the image output so you can see HTML and see if you are getting any error messages. Add some debug text as well.

<?$x = 0;$text=$_GET["text"];echo "text: {$text}<br>";$im = imagecreatetruecolor( 20*strlen($text), 20 );for ($i = 0; $i < strlen($text); ++$i){$letter = $text[$i];echo "letter: {$letter}<br>";$filename = "http://www.habbground.com/goodies/letters/$letter.png";echo "filename: {$filename}<br>";$image = imagecreatefromPNG($filename);imagecopyresampled($im, $image, $x, 0, 0, 0, 20, 20, 20, 20);imageDestroy($image);$x = $x+20;}imageDestroy($im);?>

[Tanis]

It should be working... outputting the variables returnedtext: ABCDEletter: Afilename: http://www.habbground.com/goodies/letters/A.pngletter: Bfilename: http://www.habbground.com/goodies/letters/B.pngletter: Cfilename: http://www.habbground.com/goodies/letters/C.pngletter: Dfilename: http://www.habbground.com/goodies/letters/D.pngletter: Efilename: http://www.habbground.com/goodies/letters/E.pngCopy/pasting the links returns an image.

[justsomeguy]

Check to make sure that the image is being opened correctly.

$image = imagecreatefromPNG($filename);if (!$image){  echo "failed opening {$filename}";  exit();}

[Tanis]

I added in the transparency code, ending up with

<?$x = 0;$text=$_GET["text"];$im = imagecreatetruecolor( 20*strlen($text), 20 );imagealphablending( $im, false );$col = imagecolorallocate( $im, 0, 0, 0, 127 );imagefilledrectangle( $im, 0, 0, 20*strlen($text), 20, $col );imagealphablending( $im, true );for ($i = 0; $i < strlen($text); ++$i){$letter = $text[$i];$filename = "http://www.habbground.com/goodies/letters/$letter.png";$image = imagecreatefromPNG($filename);imagecopyresampled($im, $image, $x, 0, 0, 0, 20, 20, 20, 20);$x = $x+20;}header('Content-type: image/png');imagealphablending( $im, false );imagesavealpha( $im, true );imagePNG($im);imageDestroy($im);?>

And it still has a black background.

[justsomeguy]

If you're still getting black, then there is something wrong with the copy. You didn't add the code I posted above, add this to help debug:

for ($i = 0; $i < strlen($text); ++$i){  $letter = $text[$i];  $filename = "http://www.habbground.com/goodies/letters/$letter.png";  $image = imagecreatefromPNG($filename);  if (!$image)	die("could not open {$filename}");  if (!imagecopyresampled($im, $image, $x, 0, 0, 0, 20, 20, 20, 20))	die("could not copy");  $x = $x+20;}

[Tanis]

Sorry, I should have been more clear.After adding in the debug code, I discovered the problem and fixed it.I now get the properly generated text, but the text/image still has the black background.

[justsomeguy]

OK, that means it is not copying the transparency information from the letters and is using black for transparent. That might mean that the letters do not have transparency saved with them, or maybe PHP is just not saving the alpha mask when you copy. Here are some notes from the reference for imagecreatefrompng:

If you're trying to load a translucent png-24 image but are finding an absence of transparency (like it's black), you need to enable alpha channel AND save the setting. I'm new to GD and it took me almost two hours to figure this out.<?php$imgPng = imageCreateFromPng($strImagePath);imageAlphaBlending($imgPng, true);imageSaveAlpha($imgPng, true);/* Output image to browser */header("Content-type: image/png");imagePng($imgPng); ?>

***CORRECTION*** to 07-Jun-2004 01:14 imageAlphaBlending must be false, NOT TRUE$imgPng = imageCreateFromPng($strImagePath);imageAlphaBlending($imgPng, false); <<<FALSEimageSaveAlpha($imgPng, true);

A correction... If you are to set it to FALSE, then not only does it add the transparency to wherever you put it, but it takes the transparency out of the TTF files. Setting it to TRUE however, keeps your transparency both in your PNG file, and in any TTF text you make apply to the image.

I also saw a note that most imagecopy functions do not copy transparency, but imagecopymerge does:http://www.php.net/manual/en/function.imagecopymerge.phpAs a workaround, if you don't even need transparency for this, just set the background color to white or whatever it is if you have a solid background.

[Tanis]

Neither of those worked, but I tried taking out another part, and it's working now!Thanks for all your guys' help!

[justsomeguy]

What did you do to make it work? What does the final code look like?

[Tanis]

What did you do to make it work? What does the final code look like?

<?$x = 0;$text=$_GET["text"];$im = imagecreatetruecolor( 20*strlen($text), 20 );imagealphablending( $im, false );imagesavealpha( $im, true );$col = imagecolorallocate( $im, 0, 0, 0, 127 );imagefilledrectangle( $im, 0, 0, 20*strlen($text), 20, $col );for ($i = 0; $i < strlen($text); ++$i){$letter = $text[$i];$filename = "http://www.habbground.com/goodies/letters/$letter.png";$image = imagecreatefromPNG($filename);imagecopyresampled($im, $image, $x, 0, 0, 0, 20, 20, 20, 20);$x = $x+20;}header('Content-type: image/png');imagealphablending( $im, false );imagesavealpha( $im, true );imagePNG($im);imageDestroy($im);?>

There were some issues with images I had too.PS- sorry about the really long delay, I lost my link to the thread