mozilla/pdf.js · error · FormatError

Invalid WhitePoint components, no fallback available

Q: What causes "Invalid WhitePoint components, no fallback available" in mozilla/pdf.js?

Repair the PDF so /WhitePoint has non-negative X/Z and Y exactly 1.

Error message

Invalid WhitePoint components, no fallback available

What it means

Thrown by LabCS when WhitePoint fails spec validation: XW < 0, ZW < 0, or YW !== 1. The check mirrors CalGray/CalRGB; BlackPoint and Range have fallbacks but WhitePoint does not, so an invalid value is unrecoverable.

Source

Thrown at src/core/colorspace.js:1223

    if (!whitePoint) {
      throw new FormatError(
        "WhitePoint missing - required for color space Lab"
      );
    }
    // Translate args to spec variables
    [this.XW, this.YW, this.ZW] = whitePoint;
    [this.amin, this.amax, this.bmin, this.bmax] = range || [
      -100, 100, -100, 100,
    ];

    // These are here just for completeness - the spec doesn't offer any
    // formulas that use BlackPoint in Lab
    [this.XB, this.YB, this.ZB] = blackPoint || [0, 0, 0];

    // Validate vars as per spec
    if (this.XW < 0 || this.ZW < 0 || this.YW !== 1) {
      throw new FormatError(
        "Invalid WhitePoint components, no fallback available"
      );
    }

    if (this.XB < 0 || this.YB < 0 || this.ZB < 0) {
      info("Invalid BlackPoint, falling back to default");
      this.XB = this.YB = this.ZB = 0;
    }

    if (this.amin > this.amax || this.bmin > this.bmax) {
      info("Invalid Range, falling back to defaults");
      this.amin = -100;
      this.amax = 100;
      this.bmin = -100;
      this.bmax = 100;
    }
  }

View on GitHub (pinned to 5903d58d58)

Solutions

Repair the PDF so /WhitePoint has non-negative X/Z and Y exactly 1.
Update pdf.js.
When generating PDFs, normalize WhitePoint to Y=1.

Defensive patterns

Strategy: try-catch

Type guard

function isValidWhitePoint(wp) {
  return Array.isArray(wp)
    && wp.length === 3
    && wp[0] >= 0
    && wp[1] === 1
    && wp[2] >= 0;
}

Try / catch

try {
  cs = ColorSpace.parse(res, xref, cs, pdfFunctionFactory);
} catch (e) {
  if (e instanceof FormatError && /Invalid WhitePoint components/.test(e.message)) {
    console.warn('Invalid Lab WhitePoint, falling back', e);
    cs = null;
  } else throw e;
}

Prevention

When generating /Lab color spaces, normalize /WhitePoint so Y = 1 and X, Z >= 0.
Validate untrusted PDFs before rendering.
Keep pdf.js updated.
Fall back to a default colorspace when Lab construction fails.

When it happens

Trigger: A /Lab /WhitePoint array with negative X or Z, or whose Y component is not 1.

Common situations: Malformed Lab WhitePoint from a broken color-management pipeline; hand-authored PDF; rounding leaving Y != 1.

Related errors

AI-assisted analysis of mozilla/pdf.js@5903d58d58 (2026-08-13). Data as JSON: /api/errors/07452952199829a8. Report an issue: GitHub.