Re: [JAVA2D] Problem with garbled screen repaints
I'm not sure whether this is the problem, but I may have a few minor pointers. The rectangle into which you draw is probably not what you want. You have your height and width sorted out properly, but not your origin, which should be (LEFT_MARGIN, TOP_MARGIN) rather than (0, 0), if I understand your intent correctly. The 'null' parameter is your ImageObserver; it doesn't hurt to make the parent panel your observer so that new information can be sent properly. Possibly this is your issue: the bottom-right pixels (the ones progressed lastly) aren't drawn properly because the information might never be made available. All this would change your call to [i]Graphics2D.drawImage[/i] to: [code] int x = LEFT_MARGIN, y = TOP_MARGIN; int width = getWidth() - RIGHT_MARGIN - LEFT_MARGIN: int height = getHeight() - TOP_MARGIN - BOTTOM_MARGIN; canvas.drawImage(image, x, y, width, height, this); [/code] Hope this helps. [Message sent by forum member 'tarbo' (tarbo)] http://forums.java.net/jive/thread.jspa?messageID=212048 === To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message signoff JAVA2D-INTEREST. For general help, send email to [EMAIL PROTECTED] and include in the body of the message help.
Re: [JAVA2D] Retiring the package com.sun.image.codec.jpeg
My results are 18,250ms for ImageIO and 15,172 for JpegEncode. I will try to make a more thorough test and will try JAI. Thank, Carl [Message sent by forum member 'carcour' (carcour)] http://forums.java.net/jive/thread.jspa?messageID=212065 === To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message signoff JAVA2D-INTEREST. For general help, send email to [EMAIL PROTECTED] and include in the body of the message help.
[JAVA2D] Filtered subsampling
[I sent this earlier to [EMAIL PROTECTED] but it didn't show up anywhere AFAICT] I read Chris Campbell's article on image scaling the other day: http://today.java.net/pub/a/today/2007/04/03/perils-of-image-getscaledinstance.html In the comments Chris mentioned that for very large images it is better to first use ImageIO subsampling to reduce the image first, and then use traditional scaling methods to reduce it further. In my own applications I use subsampling quite heavily (we often have 5000x5000 images which only need to be 100x100 on the screen). The problem has always been that the subsampling in ImageIO is really crude--it actually just picks out every Nth column/row and tosses all the rest. After reading much too much about sampling theory it was revealed that the solution is to use a low pass filter on the original image before downscaling, for example a Gaussian blur. If you combine this with the subsampling algorithm it isn't even terribly expensive, because you only have to calculate the blur for each of the output pixels. This inspired me to add this feature to my PNG decoder library (http://javapng.sf.net/). To subsample every 4th row/column the sample code would be something like: PngConfig config = new PngConfig.Builder() .sourceSubsampling(4, 4, 0, 0) .lowPassFilter(true) .build(); BufferedImage image = new PngImage(config).read(new File(test.png)); I've tested the result on the demo image from Chris' article and the result is on par with the best of the scaling algorithms shown there (arguably better). Now, besides being an infomercial the real reason for this message is to plead for a similar feature in ImageIO, if only for JPEG images. I just don't have it in me to write a JPEG decoder too :-) Maybe there is already a third-party library that does this? Does a RFE have any chance? Chris p.s. In case anyone is listening the bugs I reported in the PNG metadata spec are now over five years old: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4518989 === To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message signoff JAVA2D-INTEREST. For general help, send email to [EMAIL PROTECTED] and include in the body of the message help.
Re: [JAVA2D] Java 2D Enhancements in JDK 6 and JDK 7
Hi Chet, from Chris's blog, I know what you mean Single Threaded Rendering (STR). And I have learned many Java 2D knowledges from your blog, thanks! [Message sent by forum member 'ylzhao' (ylzhao)] http://forums.java.net/jive/thread.jspa?messageID=212216 === To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message signoff JAVA2D-INTEREST. For general help, send email to [EMAIL PROTECTED] and include in the body of the message help.
