?
Solved

Problems using RGBImageFilter

Posted on 1997-08-18
2
Medium Priority
?
343 Views
Last Modified: 2012-05-04
Has anyone used RGBImageFilter?  I subclassed it and mapped colors from one image to another.  The resulting image looks OK within browsers on an NT machine, but the image is "blank" (no image at all and no error messages) on a Mac.  I've tried setting the alpha channel by hand and using colors from Netscapes colormap - to no avail.  I also tried to run the applet from AppletViewer (JDK 1.0.2) with same result.  It seems specific to the Mac.  The filter also works fine on an SGI (NS 4.0.2).
Has anyone else run across this?  Could it be a problem with a different color model used on the Mac?  Does anyone know of an applet that uses the RGBImageFilter?
0
Comment
Question by:gnawed
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 10

Accepted Solution

by:
kollegov earned 300 total points
ID: 1225372
It's specific MAC's problem!
Something wrong with MAC's Netscape classes packages.

I know it for sure. I have a lot of applets at my
pages which use RGBImage filter
And with my good friend who uses Mac we found this problem.

He also had this problem with applets
supplyed by "Demicron" (www.demicron.com)

He checked this applets with TWO different models
of MAC. All the same...

You can try my "luminous" applet
from my page:
http://www.geocities.com/siliconvalley/lakes/8620
This one do not use RGBImage filter, it work with pixels
in RGBColorModel and it also has problems at MAC.

There are some other my classes "imagewave" and "lines" uses
RGBImageFilter wich can filter indexed color model.
If you want to check more applets :)

Virtual_Max
http://www.geocities.com/siliconvalley/lakes/8620

0
 
LVL 1

Author Comment

by:gnawed
ID: 1225373
Thanks for the answer kollegov.  It's good to know that I'm not going crazy.
After more work, I discovered some strange results.  If I do a fillRect() to an off-screen image and then try to RGBImageFilter the off-screen image, then NS3 or 4 on the MAC NEVER calls the filterRGB() method of RGBImageFilter!!!  In SUN's appletviewer on the MAC, the filterRGB() method gets called, but claims that all the pixels = 0 (black, with full transparency)!!!  However, if I read in an image from a URL (disk, website, etc), then it the RGBImageFilter works fine!!
I also tried to use PixelGrabber to convert the off-screen image into an integer array, then change the pixel values, and use MemoryImageSource to paste it back into another image - again, didn't work in either NS3/4 or appletviwer on the MAC.  It's possible that the RGBImageFilter uses PixelGrabber (which returned zeros again), so this may be the same problem manifested differently.  Also, if I loaded an image from a URL everything worked fine again.
Here's to platform independence!!!
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Java Flight Recorder and Java Mission Control together create a complete tool chain to continuously collect low level and detailed runtime information enabling after-the-fact incident analysis. Java Flight Recorder is a profiling and event collectio…
Introduction This article is the second of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers the basic installation and configuration of the test automation tools used by…
This theoretical tutorial explains exceptions, reasons for exceptions, different categories of exception and exception hierarchy.
This tutorial will introduce the viewer to VisualVM for the Java platform application. This video explains an example program and covers the Overview, Monitor, and Heap Dump tabs.
Suggested Courses
Course of the Month9 days, 20 hours left to enroll

762 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question