Accusoft ImagXpress 13
JPEGReduceDataEx Method

The buffer holding the input JPEG file.

The buffer holding the output JPEG file.

The quality factor of the compression improvement.

The default value is 22 for strong compression improvement while maintaining very good quality. The range is from 0-32, where 0 represents almost no compression improvement, and 32 represents the most compression improvement with some quality loss.

The transform mode for the reduce operation.

The default value is IX_TransformMode_None.

Description
This function requantizes a JPEG in memory to compress its size without requiring decompression followed by recompression.
Syntax
Visual Basic
Public Sub JPEGReduceDataEx( _
   ByVal inputJPEGData As Variant, _
   ByRef outputJPEGData As Variant, _
   ByVal qualityFactor As Long, _
   ByVal transformMode As IX_TransformMode _
) 
Parameters
inputJPEGData

The buffer holding the input JPEG file.

outputJPEGData

The buffer holding the output JPEG file.

qualityFactor

The quality factor of the compression improvement.

The default value is 22 for strong compression improvement while maintaining very good quality. The range is from 0-32, where 0 represents almost no compression improvement, and 32 represents the most compression improvement with some quality loss.

transformMode
ValueDescription
IX_TransformMode_NoneNo transform occurs.
IX_TransformMode_ToProgressiveJpegTransforms a Sequential or Baseline JPEG to a Progressive JPEG.
IX_TransformMode_ToSequentialJpegTransforms a Progressive JPEG to a Sequential or Baseline JPEG.

The transform mode for the reduce operation.

The default value is IX_TransformMode_None.

  • When transformMode is IX_TransformMode_None, the output JPEG format will match the input JPEG format.
  • When transformMode is IX_TransformMode_ToProgressiveJpeg, the output JPEG format will be progressive JPEG.

    Transforming Sequential to Progressive may result in a small increase in size.

  • When transformMode is IX_TransformMode_ToSequentialJpeg, the output JPEG format will be sequential JPEG.

    Transforming Progressive to Sequential may result in a small increase in size.

Remarks
Supports reading and writing 8-bit grayscale and 24-bit color JPEGs.
See Also

ImagXpress Object  | ImagXpress Members

 

 


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