PHP | imagecolorallocate() Function

Last Updated : 23 Aug, 2019

The imagecolorallocate() function is an inbuilt function in PHP which is used to set the color in an image. This function returns a color which is given in RGB format. Syntax:

int imagecolorallocate ( $image, $red, $green, $blue )

Parameters: This function accepts four 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.
$red: This parameter is used to set value of red color component.
$green: This parameter is used to set value of green color component.
$blue: This parameter is used to set value of blue color component.

Return Value: This function returns a color identifier on success or FALSE if the color allocation failed. Below programs illustrate the imagecolorallocate() function in PHP. Program 1:

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<?php  // It create the size of image or blank image. $image_size = imagecreatetruecolor(500, 300);  // Set the background color of image using // imagecolorallocate() function. $bg = imagecolorallocate($image_size, 0, 103, 0);  // Fill background with above selected color. imagefill($image_size, 0, 0, $bg);   // output image in the browser header("Content-type: image/png"); imagepng($image_size);  // free memory imagedestroy($image_size);  ?>

Output: imagecolorallocate function

Program 2:

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<?php  // It create the size of image or blank image. $image_size = imagecreatetruecolor(500, 300);  // Set the background color of image. $bg = imagecolorallocate($image_size, 0, 103, 0);  // Fill background with above selected color. imagefill($image_size, 0, 0, $bg);   // Set the colors of image $white_color = imagecolorallocate($image_size, 255, 255, 255);  // Draw a circle imagearc($image_size, 200, 150, 200, 200,  0, 360, $white_color); // output image in the browser header("Content-type: image/png"); imagepng($image_size);  // free memory imagedestroy($image_size);  ?>