This property sets the YCrCb subsampling ratios when saving an image in JPEG format.
[TVIkJpegSubsamp Type]
Unit
IkInit
type
TVIkJpegSubsamp = (vik411, vik422,
vik444);
Property Value
| Value | Explanation |
|---|---|
| vik411 | Y:Cr:Cb 4:1:1 |
| vik422 | Y:Cr:Cb 4:2:2 |
| vik444 | Y:Cr:Cb 4:4:4 |
Explanation
The JpegSubsamp property sets the YCrCb subsampling ratios when saving an image in JPEG format. Since the Y (luminance or brightness) plane contains more important information about the image than does the CrCb (chrominance or color) planes, it is possible to reduce the size of the CrCb planes without a great sacrifice in quality thereby reducing the size of the image. A ratio for Y:Cr:Cb of 4:4:4 represents no reduction in size whereas a ratio of 4:1:1 represents a reduction in size of 50%.
This property is enabled when the image is 24 bit color and the image is saved as a JPEG image.
Setting this value
This value can be set at run-time.
Retrieving this value
This value can be retrieved at run-time.
Differences from ImageKit7/8/9 ActiveX
The VCL constants have a "v". In ActiveX, the constants are ik411, ik422, and ik444