TECH TIP: ReportBuilder JPEG Resolution

RB relies on Delphi’s TJPEGImage for providing JPEG graphic support.

There is a TppImage.DirectDraw property that enables RB to render a graphic in two different ways.

When DirectDraw is True, the TJPEGImage renders itself directly to the screen/printer canvas. When DirectDraw is False, RB converts the TJPEGImage to a BMP and renders the BMP to the screen/printer canvas. It is during the conversion from JPEG to BMP that the screen resolution affects the output.

Printers handle color in a wide variety of ways. The color organization often differs from the screen. This makes rendering to a printer difficult. RB contains logic to render a bitmap to the printer in a high quality and consistent manner.

If you test with DirectDraw set to True, I think you will find that Delphi’s TJPEGImage cannot render itself to the printer very well. It may work on some printers and not on others.

Note: RB has an open architecture for supporting TGraphic descendants. Therefore you may be able to find another JPEG component somewhere that does a better of rendering itself to printer devices.