Raf File Size.

rbuser

We are noticing that when we save a report output to the ArchiveFile (Raf)
format and if the report has an chart as a Jpeg image in it then the size of
the Raf file is several megabytes. Of course we store the chart as a Jpeg
and not as a Bitmap. Does RB convert the Jpeg image back to Bitmap while
storing the Raf file?

If the report does not contain any charts (as jpeg images) then the RAf file
is just several KB.

Thanks,
Vikram

nicocizik

Hi Vikram,

The Archive device simply retrieves each TppPage object (which contains all
the DrawCommands for that page) and saves it to file using the
TStream.WriteComponent routine. If a TppDrawImage command is present inside
the TppPage object, it will contain a TPicture property which in turn
references the exact TGraphic descendent you are using in the report. In
your case this is a TJPEGImage object.

To answer your question, ReportBuilder does not explicitly convert any
images to Bitmaps before they are exported to an archive file. It may be
that the TPicture objects saved with the archive contain bitmap information
or that perhaps the addition of numerous JPEG images per page simply
increases the file size that much.

--
Regards,

Nico Cizik
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Thanks for the response. That makes sense.

However, we just did a quick test. We are assigning a TJpegImage to a
TppImage like this:

CurTppImage.Picture.Graphic.Assign(TJPEGImage(JpgList[j]));

Then when we check the CurTppImage.Picture.Bitmap.Height it does contain the
actual jpeg's height indicating that the Bitmap is valid and has the image
stoed in it. This is even though we are assigning a jpeg image. This is the
problem. Somehow the Jpeg image is getting converted to the corresponding
Bitmap by the TppImage or TPicture or TGrpahic object thereby increasing
the size when we print this to the Raf format.

Also, If we do a CurTppImage.Picture.Graphic.LoadFromStream then it crashes
with the error "Bitmap Image is not valid'.

Appreciate your thoughts on this.

Thanks,
Vikram

nardmoseley

The mistake in your code, you do not quite understand the architecture and
behavior of Delphi TPicture.

TPicture.Graphic is of type TGraphic, which is the abstract ancestor for
TBitmap, TJPEGImage, etc.

By default, TPicture.Graphic is a TBitmap. Therefore your code essentially
does a Bitmap.Assign(myJpegImage).

Instead try...

myPicture.Graphic := myJPEGImage;

To understand this, have a look at the Delphi unit, Graphics.pas, the method
TPicture.SetGraphic.




--
Nard Moseley
Digital Metaphors
www.digital-metaphors.com

rbuser

We tried that but now the RAF file does not contain any image at all.
I think there's more to this.

Is there is a RB sample that demostrates TppImage usage?

nardmoseley

The ArchiveReader application will need to include ppJpeg in the uses
clause.

TppImage.Picture is a of type TPicture, which is a Delphi class. Check out
the Delphi unit, Graphics.pas, the method TPicture.SetGraphic.

ReportBuilder Documentation for TppImage includes:

The RBuilder help
The Demos installed with the product.
rbWiki


--
Nard Moseley
Digital Metaphors
www.digital-metaphors.com