THPDFImageRecompressionCostInfo Record

Telemetry of a visual-cost image recompression pass: scanned and candidate counts, per-codec outcomes, trial and rejection counters, quality and error aggregates, and byte savings

Declaration

THPDFImageRecompressionCostInfo= record
  ScannedImageCount: Integer;
  CandidateImageCount: Integer;
  RecompressedImageCount: Integer;
  RecompressedJPEGCount: Integer;
  RecompressedJPEG2000Count: Integer;
  EncodingTrialCount: Integer;
  VisualErrorRejectionCount: Integer;
  ByteCostRejectionCount: Integer;
  SelectedQualitySum: Integer;
  MaximumSelectedPerceptualError: Double;
  BytesBefore: Int64;
  BytesAfter: Int64;
  BytesSaved: Int64;
  DeterministicSelection: boolean;
end;

Unit

HPDFDoc

Fields

Field	Purpose
`ScannedImageCount`	Images inspected by the pass
`CandidateImageCount`	Images that entered the quality search after eligibility checks
`RecompressedImageCount`	Images actually re-encoded and written back
`RecompressedJPEGCount`	Re-encoded images whose final filter is JPEG
`RecompressedJPEG2000Count`	Re-encoded images whose final filter is JPEG 2000
`EncodingTrialCount`	Trial encodings performed while sweeping the quality range
`VisualErrorRejectionCount`	Trials rejected because the perceptual error exceeded the budget
`ByteCostRejectionCount`	Trials rejected because the byte-cost weight dominated the score
`SelectedQualitySum`	Sum of the qualities chosen per recompressed image, for computing an average
`MaximumSelectedPerceptualError`	Highest perceptual error among accepted recompressions
`BytesBefore` / `BytesAfter`	Image stream bytes before and after the pass
`BytesSaved`	Byte difference achieved; compare with the options' minimum-savings threshold
`DeterministicSelection`	`true` when every reported choice came from the deterministic cost comparison

Usage notes

Filled by THotPDF.OptimizeLoadedImagesByVisualCost; the function result is the number of images recompressed and the record carries the full accounting
Divide SelectedQualitySum by RecompressedImageCount to report the average chosen quality
Read BytesBefore, BytesAfter, and BytesSaved after the call to verify the pass met the configured savings goal

THPDFImageRecompressionCostInfo Record

Declaration

Unit

Fields

Usage notes

Related APIs