massive quality changing by GdPicture rotate

[ClipFix1]

GdPicture.RotateXXX or GdPicture.FlipXXX returns quality-changing. By using 4 x Rotate90 you have massiv deterioration, please have a look at attachment

[Loïc]

Hi,

Do you have a code snippet which reproduces the problem ?

Kind regards,

Loïc

[ClipFix1]

Code: Select all

Imaging.CreateImageFromFile(MyFile)
Dim nClonedImage As Long = Imaging.CreateClonedImageI(Imaging.GetNativeImage)
ImagingCloseNativeImage()
Imaging.SetNativeImage(nClonedImage)
GdPicture.SetNativeImage(nClonedImage)
GdPicture.Rotate90()
Imaging.SaveAsJPEG(MyFile, 100)


[Loïc]

OK I see,

You make successive OPEN/SAVE action using JPEG format. Keep in mind that JPEG is a lossy compression scheme. Therefore you will lost image information each time you will save.

A workaround consists to use a lossless compression scheme such as PNG.

Kind regards,

Loïc

[ClipFix1]

Thx.

OK, I understand. But not realy workaround, because save from PNG as JPG, you even lost informationen.

[ClipFix1]

I try with Image.RotateFlip by vb.net-roots. The lost of informationen is minimal even after 10 turns with vb.net-save-methode. May be the dgpictiure-save-method optimize in next times.