Programming PHP

Images with Text

Often it is necessary to add text to images. GD has built-in fonts for this purpose. Example 9-4 adds some text to our black square image.

Example 9-4. Adding text to an image

<?php
 $im = ImageCreate(200,200);
 $white = ImageColorAllocate($im,0xFF,0xFF,0xFF);
 $black = ImageColorAllocate($im,0x00,0x00,0x00);
 ImageFilledRectangle($im,50,50,150,150,$black);
 ImageString($im,5,50,160,"A Black Box",$black);
 Header('Content-Type: image/png');
 ImagePNG($im);
?>

Figure 9-2 shows the output of Example 9-4.

Figure 9-2. The image with text

The ImageString( ) function adds text to an image. Specify the top-left point of the text, as well as the color and the font to use:

ImageString(image, font, x, y, text, color);

Fonts

Fonts in GD are identified by numbers. The five built-in fonts are shown in Figure 9-3.

Figure 9-3. Native GD fonts

You can create your own fonts and load them into GD using the ImageLoadFont( ) function. However, these fonts are binary and architecture-dependent. Using TrueType fonts with the TrueType functions in GD provides much more flexibility.

TrueType Fonts

To use TrueType fonts with GD, PHP must have been compiled with TrueType support via the FreeType library. Check your phpinfo( ) page (as described earlier in this chapter) to see if your “GD” section ...