ConFoo 2025

imagescale

(PHP 5 >= 5.5.0, PHP 7, PHP 8)

imagescaleScale an image using the given new width and height

Description

imagescale(
    GdImage $image,
    int $width,
    int $height = -1,
    int $mode = IMG_BILINEAR_FIXED
): GdImage|false

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

Note:

Unlike many of other image functions, imagescale() does not modify the passed image; instead, a new image is returned.

Parameters

image

A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().

width

The width to scale the image to.

height

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

mode

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

Note: IMG_WEIGHTED4 is not yet supported.

Return Values

Return the scaled image object on success or false on failure.

Errors/Exceptions

Throws a ValueError if width or height would cause over-/underflow.

Throws a ValueError if mode is invalid.

Changelog

Version Description
8.4.0 Now throws a ValueError if width or height would cause over-/underflow.
8.4.0 Now throws a ValueError if mode is invalid.
8.0.0 On success, this function returns a GDImage instance now; previously, a resource was returned.
8.0.0 image expects a GdImage instance now; previously, a valid gd resource was expected.

See Also

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User Contributed Notes 1 note

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Anonymous
1 year ago
Seemingly, you can't omit the width the same way you do with the height. If you write -1 for the width and specify a number for the height it will return false
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