The imagetruecolortopalette() function is an inbuilt function in PHP which is used to convert a true color image to a palette image.
Syntax:
bool imagetruecolortopalette( $image, $dither, $ncolors )
Parameters: This function accepts three parameters as mentioned above and described below:
- $image: It is returned by one of the image creation functions, such as imagecreatetruecolor(). It is used to create size of image.
- $dither: It is the boolean value which indicate the image is dither. If it is True then dithering will be used which will result in a more speckled image but with better color approximation.
- $ncolors: This parameter contains the set of maximum number of colors that should be retained in the palette.
Return Value: This function returns True on success or False on failure.
Below programs illustrates the imagetruecolortopalette() function in PHP:
Program 1:
<?php   // Create a 400*300 image $im = imagecreatetruecolor(400, 300);   // Set the background color of image $background_color = imagecolorallocate($im, 0, 153, 0);        // Fill background with above selected color imagefill($im, 0, 0, $background_color);   // Convert to palette-based with no dithering and 255 colors imagetruecolortopalette($im, true, 255);   // Output the picture to the browser header('Content-type: image/png');        imagepng($im); ?> |
Output:
Program 2:
<?php   // Setup the true color and palette images $im = imagecreatefrompng(   // Convert to palette-based with no dithering and 255 colors imagetruecolortopalette($im, false, 255);   // Output the picture to the browser header('Content-type: image/png');        imagepng($im); ?> |
Output:
Reference: http://php.net/manual/en/function.imagetruecolortopalette.php
