sales
10/21/2004 3:41:00 AM
I work with customers (and friends) that view, print, and manage
scanned images. These scanned documents are typically letter or legal
size scanned at 200 or 300 dpi. They can be single and multi-page
Tiffs. In the past, I've been able to deliver free or near free
imaging utilities using VB5 and Wang/Kodak/eiStream Imaging for
Windows OCXs. So as more folk move to XP, I'm looking for a new way
to help out. I'm just now getting on the GDI+ VB.NET platform and was
wondering if anyone could comment on some of the challenges I'm
running into as I get my feet wet on a simple View/Print application.
I've search for a few GDI+ books and most seem to be using GDI+ with
C#.
Issues and questions:
Graphics Object ? I not quite getting why and how to use the OnPaint
Override event to render the Bitmap on the object. Can someone
explain, at a high level, how to allow the UI to trigger a new image
to be displayed using an event raised from a click event using
listview or similar control? I see in other posting and FAQs that
some folks use the CreateGraphics instead of the OnPaint. When do you
use which one.
Picturebox vs. panel vs. form ? I tried the PictureBox first but the
scaled image was unusable on a typical 1024x768 screen. Are there any
advantages to using a PictureBox? Can you use Interpolation like
HighQualityBicubic and the PicBox at the same time?
S L O W ? Ack! The included Fax/Image viewer on my Windows XP box
scales and displays TIFFs at a nice speed. My GDI+ using
e.Graphics.InterpolationMode = InterpolationMode.HighQualityBicubic to
display that same image is about 10 times slower. I tried all the
Interpolation Modes and the quality was poor or the speed is slow.
What method should I use to achieve what document imaging components
term: scale-to-gray?
Thanks!
Doug DeBug