insertar texto en diagonal a una grafico

[andresdzphp]

Te dejo un ejemplo funcional del manual php:

Código PHP:

<?php
header('Content-Type: image/jpg');
$WatermarkNeeded = true;
/* Get image info */
$Image = @ImageCreateFromJPEG ("YourImage.jpg") ;
$sx = imagesx($Image) ;
$sy = imagesy($Image) ;
if ($WatermarkNeeded)
    {
    /* Set text info */
    $Text="Copyright Ben Clay" ;
    $Font="arial.ttf" ;
    $FontColor = ImageColorAllocate ($Image,255,255,255) ;
    $FontShadow = ImageColorAllocate ($Image,0,0,0) ;
    $Rotation = 30 ;
    /* Make a copy image */
    $OriginalImage = ImageCreateTrueColor($sx,$sy) ;
    ImageCopy ($OriginalImage,$Image,0,0,0,0,$sx,$sy) ;
    /* Iterate to get the size up */
    $FontSize=1 ;
    do
        {
        $FontSize *= 1.1 ;
        $Box = @ImageTTFBBox($FontSize,0,$Font,$Text);
        $TextWidth = abs($Box[4] - $Box[0]) ;
        $TextHeight = abs($Box[5] - $Box[1]) ;
        }
    while ($TextWidth < $sx*0.7) ;
    /*  Awkward maths to get the origin of the text in the right place */ 
    $x = $sx/2 - cos(deg2rad($Rotation))*$TextWidth/2 ;
    $y = $sy/2 + sin(deg2rad($Rotation))*$TextWidth/2 + cos(deg2rad($Rotation))*$TextHeight/2 ;
    /* Make shadow text first followed by solid text */
    ImageTTFText ($Image,$FontSize,$Rotation,$x+4,$y+4,$FontShadow,$Font,$Text);
    ImageTTFText ($Image,$FontSize,$Rotation,$x,$y,$FontColor,$Font,$Text);
    /* merge original image into version with text to show image through text */
    ImageCopyMerge ($Image,$OriginalImage,0,0,0,0,$sx,$sy,50) ;
    }
 
ImageJPEG ($Image) ;
?>
 

http://php.net/manual/en/function.im...text.php#70946

O también conozco esta clase ImageWorkshop, que hace casi lo mismo:

http://phpimageworkshop.com/tutorial...watermark.html

Saludos.