Function getImageDimensions

benchmark/helpers.ts:104–152

(
  base64Data: string,
  mimeType: ImageMimeType
)

}

export function getImageDimensions(
  base64Data: string,
  mimeType: ImageMimeType
): { width: number; height: number } | null {
  try {
    const buffer = Buffer.from(base64Data, "base64");

    if (mimeType === "image/png") {
      const png = PNG.sync.read(buffer);
      return { width: png.width, height: png.height };
    }

    if (mimeType === "image/jpeg") {
      const decoded = jpeg.decode(buffer, { useTArray: true });
      return { width: decoded.width, height: decoded.height };
    }

    if (mimeType === "image/gif") {
      if (buffer.length >= 10) {
        const width = buffer.readUInt16LE(6);
        const height = buffer.readUInt16LE(8);
        return { width, height };
      }
    }

    if (mimeType === "image/webp") {
      if (buffer.length >= 30 && buffer.toString("ascii", 0, 4) === "RIFF") {
        const webpType = buffer.toString("ascii", 8, 12);
        if (webpType === "WEBP") {
          if (buffer.toString("ascii", 12, 16) === "VP8 ") {
            const width = buffer.readUInt16LE(26) & 0x3fff;
            const height = buffer.readUInt16LE(28) & 0x3fff;
            return { width, height };
          }
          if (buffer.toString("ascii", 12, 16) === "VP8L") {
            const bits = buffer.readUInt32LE(21);
            const width = (bits & 0x3fff) + 1;
            const height = ((bits >> 14) & 0x3fff) + 1;
            return { width, height };
          }
        }
      }
    }

    return null;
  } catch {
    return null;
  }
}

export function calculateImageTokensFromBase64(
  base64Data: string,