Actually this produces black and white images only, as does the jpeg2wbmp function.
(PHP 4 >= 4.0.5, PHP 5, PHP 7)
jpeg2wbmp — Convert JPEG image file to WBMP image file
Converts a JPEG file into a WBMP file.
Path to JPEG file.
Path to destination WBMP file.
Destination image height.
Destination image width.
Threshold value, between 0 and 8 (inclusive).
TRUE on success or
FALSE on failure.
Example #1 jpeg2wbmp() example
// Path to the target jpeg
$path = './test.jpg';
// Get the image sizes
$image = getimagesize($path);
// Convert image
jpeg2wbmp($path, './test.wbmp', $image, $image, 5);
Note: WBMP support is only available if PHP was compiled against GD-1.8 or later.
Note: JPEG support is only available if PHP was compiled against GD-1.8 or later.