Demo: High quality image resizing

Author

Message

Sergey Tkachenko

Posted: 09/09/2004 23:06:24

When you resize image in editor (with mouse or by assiging

rvepImageWidth/rvepImageHeight item properties), the image itself is not

modified. It's drawn stretched (TCanvas.StretchDraw is used). StretchDraw

uses the simplest resizing algorithm, so bitmaps are displayed in low

quality.

This demo shows how to resize bitmaps to their display size using high

quality resizing algorithm (Anders Melander's Interpolating Bitmap

Resampler, included):

http://www.trichview.com/support/files/stretch.zip

This operation makes sense only if application creates documents for reading

from screen. If it creates document for printing, it can degrade images

quality, especially if images are scaled down.

This operation cannot be undone. Let me know if you need undoable version.

When you open this demo, Delphi may warn about unknown properties (it's

because

it's created with newest version - currently in development). Press Ignore

and save the project before running.