Intervention/image · error · Intervention\Image\Exceptions\ModifierException

Failed to apply {class}, unable to adjust image gamma

Error message

Failed to apply {class}, unable to adjust image gamma

What it means

This ModifierException is thrown by $image->gamma($value) when the native gamma correction reports failure by returning false. The Imagick driver calls gammaImage($this->gamma) on every frame; a false return means ImageMagick refused the gamma value or could not apply it, and the driver converts it to 'unable to adjust image gamma' without a chained previous exception.

Source

Thrown at src/Drivers/Imagick/Modifiers/GammaModifier.php:24

use ImagickException;
use Intervention\Image\Exceptions\ModifierException;
use Intervention\Image\Interfaces\ImageInterface;
use Intervention\Image\Interfaces\SpecializedInterface;
use Intervention\Image\Modifiers\GammaModifier as GenericGammaModifier;

class GammaModifier extends GenericGammaModifier implements SpecializedInterface
{
    /**
     * @throws ModifierException
     */
    public function apply(ImageInterface $image): ImageInterface
    {
        foreach ($image as $frame) {
            try {
                $result = $frame->native()->gammaImage($this->gamma);
                if ($result === false) {
                    throw new ModifierException(
                        'Failed to apply ' . self::class . ', unable to adjust image gamma',
                    );
                }
            } catch (ImagickException $e) {
                throw new ModifierException(
                    'Failed to apply ' . self::class . ', unable to adjust image gamma',
                    previous: $e,
                );
            }
        }

        return $image;
    }
}

View on GitHub (pinned to 5598b9e397)

Solutions

1. Clamp gamma to a sane positive range (commonly 0.1 to 10) before calling gamma()
2. Check the value is a finite number (not NAN/INF) before use
3. Downscale very large images or raise resource limits if the value is valid but the op fails
4. Inspect ImageMagick policy.xml if valid values still fail
5. Compare with the GD driver to isolate environment-specific failures

Example fix

// before
$image->gamma($request->float('gamma')); // 0, -2 or 1e30 pass straight through

// after
$gamma = $request->float('gamma');
$gamma = min(10.0, max(0.1, (float) $gamma)); // clamp to 0.1..10
if (!is_finite($gamma)) {
    $gamma = 1.0;
}
$image->gamma($gamma);

$gamma = (float) $gamma;
if (!is_finite($gamma) || $gamma < 0.1) {
    $gamma = 1.0; // neutral fallback
}
$gamma = min(10.0, $gamma); // clamp upper bound
$image->gamma($gamma);

function isValidGamma(mixed $value): bool
{
    return is_int($value) || is_float($value)
        ? is_finite($value) && $value >= 0.1 && $value <= 10.0
        : false;
}

use Intervention\Image\Exceptions\ModifierException;

try {
    $image->gamma($gamma);
} catch (ModifierException $e) {
    Log::warning('Gamma failed for value ' . var_export($gamma, true));
    $image->gamma(1.0); // neutral retry
}

When it happens

Trigger: Calling $image->gamma($g) with a value outside the range accepted by ImageMagick (values <= 0, or extreme magnitudes); applying gamma to frames whose pixel cache cannot be processed under current resource limits; policy-restricted environments blocking channel-wide operations.

Common situations: User-supplied gamma values (e.g. from an editing UI slider) passed through without range validation; gamma 0 or negative values from arithmetic that should be clamped; processing very large images near memory limits; shared hosts restricting ImageMagick operations.

Related errors

• Failed to apply {class}, unable to set image resolution
• Failed to apply Intervention\Image\Drivers\Imagick\Modifiers
• Failed to apply Intervention\Image\Drivers\Imagick\Modifiers
• Failed to apply Intervention\Image\Drivers\Imagick\Modifiers
• Failed to apply Intervention\Image\Drivers\Imagick\Modifiers

AI-assisted analysis of Intervention/image@5598b9e397 (2026-08-23). Data as JSON: /api/errors/23220f164d81f99e. Report an issue: GitHub.