php man page for imagescale

IMAGESCALE(3)								 1							     IMAGESCALE(3)

imagescale - Scale an image using the given new width and height

SYNOPSIS
       resource imagescale (resource  $image, int  $new_width, [int  $new_height = -1], [int  $mode = IMG_BILINEAR_FIXED])

DESCRIPTION
       imagescale(3) scales an image using the given interpolation algorithm.

PARAMETERS
	      o $
		image -An image resource, returned by one of the image creation functions, such as imagecreatetruecolor(3).

	      o $new_width
		- The width to scale the image to.

	      o $new_height
		- The height to scale the image to. If omitted or negative, the aspect ratio will be preserved.

	      Caution

		      You  should  always provide the height if using PHP 5.5.18 or earlier, or PHP 5.6.2 or earlier, as the aspect ratio calcula-
		     tion was incorrect.

	      o $mode
		- One of IMG_NEAREST_NEIGHBOUR, IMG_BILINEAR_FIXED, IMG_BICUBIC, IMG_BICUBIC_FIXED or anything else (will use two pass).

RETURN VALUES
	Return the scaled image resource on success or FALSE on failure.

CHANGELOG
       +-------------+---------------------------------------------------+
       |  Version    |							 |
       |	     |							 |
       |	     |			  Description			 |
       |	     |							 |
       +-------------+---------------------------------------------------+
       |5.5.19/5.6.3 |							 |
       |	     |							 |
       |	     |	The calculation of the height if $new_height was |
       |	     | negative  or  omitted  was  fixed; prior to these |
       |	     | versions, the aspect  ratio  was  not  maintained |
       |	     | correctly.					 |
       |	     |							 |
       +-------------+---------------------------------------------------+
PHP Documentation Group 													     IMAGESCALE(3)