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PdfDCTDecodeFilterColorTransform Property

A value specifying the transformation that shall be performed on the sample values:

0
No transformation.
1
If the image has three color components, RGB values shall be transformed to YUV before encoding and from YUV to RGB after decoding. If the image has four components, CMYK values shall be transformed to YUVK before encoding and from YUVK to CMYK after decoding. This option shall be ignored if the image has one or two color components.

Default value: if the image has three components; otherwise, .

Namespace:  GemBox.Pdf.Filters
Assembly:  GemBox.Pdf (in GemBox.Pdf.dll) Version: 13.0.35.1000
Syntax
public Nullable<bool> ColorTransform { get; set; }

Property Value

Type: NullableBoolean
The value specifying the transformation that shall be performed on the sample values.
Exceptions
Remarks

If the encoding algorithm has inserted the Adobe-defined marker code in the encoded data indicating the ColorTransform value, then the colors shall be transformed, or not, after the DCT decoding has been performed according to the value provided in the encoded data and the value of this property shall be ignored. If the Adobe-defined marker code in the encoded data indicating the ColorTransform value is not present then the value specified in this property will be used. If the Adobe-defined marker code in the encoded data indicating the ColorTransform value is not present and value of this property is then the default value of ColorTransform shall be if the image has three components and otherwise.

Parameters that control the decoding process as well as other metadata is embedded within the encoded data stream using a notation referred to as “markers”. When it defined the use of JPEG images within PostScript data streams, Adobe System Incorporated defined a particular set of rules pertaining to which markers are to be recognized, which are to be ignored and which are considered errors. A specific Adobe-defined marker was also introduced. The exact rules for producing and consuming DCT encoded data within PostScript are provide in Adobe Technical Note #5116 (reference). PDF DCT Encoding shall exactly follow those rules established by Adobe for PostScript.

See Also