ImageGear22.Recognition Assembly > ImageGear.Recognition Namespace > ImGearRecPDFOutputOptions Class : ImageCompression Property |
'Declaration Public Property ImageCompression As ImGearCompressions
'Usage Dim instance As ImGearRecPDFOutputOptions Dim value As ImGearCompressions instance.ImageCompression = value value = instance.ImageCompression
public ImGearCompressions ImageCompression {get; set;}
public: __property ImGearCompressions get_ImageCompression(); public: __property void set_ImageCompression( ImGearCompressions value );
public: property ImGearCompressions ImageCompression { ImGearCompressions get(); void set ( ImGearCompressions value); }
This property will determine the compression format of the image that is added to the PDF page when VisibleImage is true
. The original image imported into Recognition will be used.
The default value, ImGearCompressions.AUTO, will result in the following automatic compression selection based on the input image's bit depth:
For compression types other than AUTO
, the Recognition PDF writer will attempt to convert the original image if needed to make it compatible with the selected compression format. However, this conversion process does not support the binarization of full color, 24 BPP images to black and white, 1 BPP images. If the original input might be a full color image, the CCITT
compression types should not be selected as this will cause an exception. Binarization should be performed on the original image, prior to importing it into Recognition, if the PDF output should need it.
If JPEG compression is set here, the compression quality can be adjusted using the global ImageGear filter parameters. The Quality and DecimationType values will be used for JPEG compression of images in the recognition PDF output. All other JPEG filter parameters are ignored. See the JPEG format topic for more information about these parameters. See the Using Filter Control Parameters topic for information on how to set the global filter parameters.