{
  "context": "This criteria evaluates how well the engineer uses pixelmatch's alpha option to control background visibility in diff outputs. The focus is on correctly using the alpha parameter to generate three distinct visualization modes with varying levels of context preservation.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Alpha option usage",
      "description": "Uses the pixelmatch `alpha` option to control background visibility for diff outputs. Must call pixelmatch with different alpha values (e.g., 0.0, 0.1, 1.0 or similar) to create the three required visualization modes.",
      "max_score": 40
    },
    {
      "name": "Correct alpha values",
      "description": "Uses appropriate alpha values that achieve the specified effects: low value (0.0-0.2) for high contrast with near-white background, medium value (0.3-0.6) for balanced mode, and high value (0.7-1.0) for context preserved mode with full original brightness.",
      "max_score": 25
    },
    {
      "name": "Diff output buffer",
      "description": "Creates properly allocated output buffers for pixelmatch to write diff visualization data. The output buffer must be a Uint8Array or Uint8ClampedArray with length equal to width × height × 4.",
      "max_score": 15
    },
    {
      "name": "DiffColor configuration",
      "description": "Configures pixelmatch with the `diffColor` option set to red [255, 0, 0] to highlight differing pixels as specified in requirements.",
      "max_score": 10
    },
    {
      "name": "Mismatch count reporting",
      "description": "Captures and reports the mismatch count returned by pixelmatch, which represents the number of differing pixels found in the comparison.",
      "max_score": 10
    }
  ]
}