{"record":{"id":"b086effdaaf863aa","repo":"Intervention/image","slug":"failed-to-read-pixel-color-at-position","errorCode":null,"errorMessage":"Failed to read pixel color at position ","messagePattern":"Failed to read pixel color at position ","errorType":"exception","errorClass":"Intervention\\Image\\Exceptions\\AnalyzerException","httpStatus":null,"severity":"error","filePath":"src/Drivers/Imagick/Analyzers/PixelColorAnalyzer.php","lineNumber":48,"sourceCode":"            );\n        }\n\n        $colorProcessor = $this->driver()->colorProcessor($image);\n\n        return $this->colorAt($colorProcessor, $image->core()->frame($this->frame));\n    }\n\n    /**\n     * @throws AnalyzerException\n     */\n    protected function colorAt(ColorProcessorInterface $processor, FrameInterface $frame): ColorInterface\n    {\n        try {\n            return $processor->import(\n                $frame->native()->getImagePixelColor($this->x, $this->y),\n            );\n        } catch (ImagickException $e) {\n            throw new AnalyzerException(\n                'Failed to read pixel color at position ' . $this->x . ', ' . $this->y,\n                previous: $e,\n            );\n        }\n    }\n}\n","sourceCodeStart":30,"sourceCodeEnd":55,"githubUrl":"https://github.com/Intervention/image/blob/5598b9e39751c34afc5cdee84abef77f92c26f68/src/Drivers/Imagick/Analyzers/PixelColorAnalyzer.php#L30-L55","documentation":"After passing the library's upper-bound check, Imagick's getImagePixelColor($x, $y) itself threw and was wrapped as AnalyzerException. Because the validation in analyze() only rejects x > width-1 / y > height-1, negative coordinates sail through and make Imagick fail inside colorAt(); the remaining cause is a damaged frame resource.","triggerScenarios":"colorAt(-1, 0) or colorAt(0, -5) — negative indices from modulo/wrapping math, signed arithmetic, or sentinel defaults like -1; reading a pixel from a frame whose Imagick internal state is corrupted.","commonSituations":"Tiling/wrapping code using (($i - 1) % $width); coordinates parsed from user input or template variables that permit negatives; neighbor-pixel lookups at x=0/y=0 edges.","solutions":["Reject or clamp negative coordinates before calling colorAt() — they pass the library's check but are invalid for Imagick.","If coordinates are already non-negative, re-read the image from the original bytes and retry once; persistent failure indicates a corrupt file."],"exampleFix":"// before\n$color = $image->colorAt($x - 1, $y); // $x == 0 makes this -1\n\n// after\n$left = max(0, $x - 1);\n$color = $image->colorAt($left, $y);","handlingStrategy":"validation","validationCode":"// the library only guards the upper bound; negatives must be checked by the caller\nif ($x < 0 || $y < 0 || $x >= $image->width() || $y >= $image->height()) {\n    throw new \\InvalidArgumentException(\"Pixel ($x, $y) is outside the image\");\n}\n$color = $image->colorAt($x, $y);","typeGuard":"function isValidPixel(\\Intervention\\Image\\Interfaces\\ImageInterface $image, int $x, int $y): bool\n{\n    return $x >= 0 && $y >= 0 && $x < $image->width() && $y < $image->height();\n}","tryCatchPattern":"try { $color = $image->colorAt($x, $y); } catch (AnalyzerException $e) { /* coordinates already validated → suspect corrupt frame: re-read from bytes */ }","preventionTips":["Watch neighbor lookups at edges: $x - 1 at x=0 is -1 and passes the library check.","Use max(0, ...) around modulo/wrapping index math.","Reject negative coordinates from user input or templates."],"tags":["imagick","coordinates","colorat","negative-index","getimagepixelcolor"],"backgroundTag":"pixel-coordinate-out-of-bounds","analyzedSha":"5598b9e39751c34afc5cdee84abef77f92c26f68","analyzedAt":"2026-08-23T02:17:31.068Z","schemaVersion":2},"datasetVersion":"2026-08-23T08:06:27.607Z"}