CRasterImage::SetCompressQuality

void SetCompressQuality( int CompressionQuality );

Parameters

CompressionQuality Compression quality factor. Value from 0 to 100. The higher the factor is the higher is quality of image being compressed. However the higher image quality means that byte size of compressed image (what can mean file size) is also higher. The relationship between compression quality factor and byte size of image is not linear and vary from image to image. Default compression quality factor value is set during CRasterImage object initialization to 80

Following table shows an example of various compression quality factor settings and resulting JPEG file size.

Original BMP file size:318 438 Bytes
Compression QualityJPEG file size
-1 3 047 Bytes
10 5 856 Bytes
20 9 015 Bytes
30 10 662 Bytes
40 15 071 Bytes
50 17 702 Bytes
60 18 984 Bytes
70 20 152 Bytes
80 24 620 Bytes
90 30 997 Bytes
100 85 353 Bytes

Remarks

Compression quality factor affects compression of JPEG images only. It does not affect other image format types such as GIF.

This method is available from ClassGL version 3.1

See Also

GetCompressQuality