{"record":{"id":"1371d4c510561197","repo":"Intervention/image","slug":"failed-to-apply-class-unable-to-invert-image-co","errorCode":null,"errorMessage":"Failed to apply {class}, unable to invert image colors","messagePattern":"Failed to apply (.+?), unable to invert image colors","errorType":"exception","errorClass":"Intervention\\Image\\Exceptions\\ModifierException","httpStatus":null,"severity":"error","filePath":"src/Drivers/Imagick/Modifiers/InvertModifier.php","lineNumber":32,"sourceCode":"class InvertModifier extends GenericInvertModifier implements SpecializedInterface\n{\n    /**\n     * @throws ModifierException\n     */\n    public function apply(ImageInterface $image): ImageInterface\n    {\n        // Imagick::CHANNEL_DEFAULT includes the alpha channel, so a plain\n        // negateImage() call inverts transparency along with color and turns\n        // fully transparent pixels opaque. Mask the alpha bit off so the\n        // result matches the GD driver, where IMG_FILTER_NEGATE only touches\n        // the color channels.\n        $channel = Imagick::CHANNEL_ALL & ~Imagick::CHANNEL_ALPHA;\n\n        foreach ($image as $frame) {\n            try {\n                $result = $frame->native()->negateImage(false, $channel);\n                if ($result === false) {\n                    throw new ModifierException(\n                        'Failed to apply ' . self::class . ', unable to invert image colors',\n                    );\n                }\n            } catch (ImagickException $e) {\n                throw new ModifierException(\n                    'Failed to apply ' . self::class . ', unable to invert image colors',\n                    previous: $e,\n                );\n            }\n        }\n\n        return $image;\n    }\n}\n","sourceCodeStart":14,"sourceCodeEnd":47,"githubUrl":"https://github.com/Intervention/image/blob/5598b9e39751c34afc5cdee84abef77f92c26f68/src/Drivers/Imagick/Modifiers/InvertModifier.php#L14-L47","documentation":"Thrown by the Imagick driver when Imagick::negateImage() returns false instead of throwing while inverting a frame's color channels (alpha bit masked off so transparency stays intact). The library converts the falsy native return into a ModifierException so that both failure shapes (boolean false and ImagickException) surface as one exception type. A bare false return without a chained exception is the rarer path and usually points to a low-level ImageMagick refusal rather than bad input data.","triggerScenarios":"Calling $image->invert() on the Imagick driver and negateImage() returning false for at least one frame: ImageMagick security policy (policy.xml) denies the operation, the pixel cache for the frame cannot be allocated, or an old imagick extension build reports failure instead of throwing.","commonSituations":"Shared hosting with restrictive /etc/ImageMagick-*/policy.xml; very large images that exhaust PHP memory_limit before Imagick can negate; imagick PECL extension compiled against a mismatched libmagick version after a system update.","solutions":["Catch ModifierException and read $e->getPrevious()?->getMessage() to get the native ImageMagick reason","Check the installed stack: php -i | grep -i imagick and Imagick::getVersion(), then upgrade the imagick extension if it predates ImageMagick 6.9/7.x","Compare memory_limit with the frame size (width x height x 4 bytes) and raise it, or inspect policy.xml for denied operations","Re-encode the source file (e.g. re-save it) to rule out truncated image data, then retry the invert"],"exampleFix":"// before\n$image->invert(); // unguarded\n\n// after\nuse Intervention\\Image\\Exceptions\\ModifierException;\n\ntry {\n    $image->invert();\n} catch (ModifierException $e) {\n    $reason = $e->getPrevious()?->getMessage() ?? $e->getMessage();\n    $logger->error('Invert failed: ' . $reason);\n}","handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"use Intervention\\Image\\Exceptions\\ModifierException;\n\ntry {\n    $image->invert();\n} catch (ModifierException $e) {\n    $reason = $e->getPrevious()?->getMessage() ?? 'no native error';\n    // decision point: log, skip modifier, or rethrow\n}","preventionTips":["Size memory_limit to at least width x height x 4 bytes per frame before inverting large images","Keep imagick PECL and libmagick versions in sync when upgrading the system ImageMagick","Audit policy.xml on deployment targets before shipping Imagick-driver pipelines"],"tags":["php","imagick","intervention-image","invert","negateimage","imagemagick-policy"],"backgroundTag":"image-color-inversion-failed","analyzedSha":"5598b9e39751c34afc5cdee84abef77f92c26f68","analyzedAt":"2026-08-23T02:17:31.068Z","schemaVersion":2},"datasetVersion":"2026-08-23T08:06:27.607Z"}