Re: drawImage speed (solved)

On 2 Nov 2005, at 19:13, Michael McDougall wrote:

We're very interested in taking a closer look at this case. It would be great if you could provide a testcase that we could run from the command line, rather than pseudo-code, so we can be sure that we are actually investigating the same issue that you are seeing.

In particular, "swap image1 and image2" is vague. If you are doing direct pixel manipulation (like setpixel) that this is known to be a very non-optimal (aka abysmal) case.

Hi,

Thanks for the speedy reply, and thanks also to Jeremy Wood who sent me a test program which nudged me on the right track. After a long time transforming my code and the test code into the same form and still getting totally different results, I had a D'Oh! moment. I said in the original post that my image was TYPE_INT_ARGB. However, this turned out not to be the case. In my test program I was using ImageIO.read to read a PNG image and it turned out to be of TYPE_CUSTOM. Normally, I make sure that I''ve got TYPE_INT_ARGB images, but the conversion got missed out by accident. Converting to TYPE_INT_ARGB did the trick. The TYPE_CUSTOM case is still way slower than Windows though, (but I don't care).

Jerry

For reference, here's cut down code which illustrates the problem:

BufferedImage dst = createCompatibleDestImage( src, null );

BufferedImage tmp = createCompatibleDestImage( src, null );

for ( int i = 0; i < steps; i++ ) {

Graphics2D g = tmp.createGraphics();

long t1 = System.currentTimeMillis();

g.drawImage( tsrc, null, null );

t1 = System.currentTimeMillis()-t1;

long t2 = System.currentTimeMillis();

g.drawImage( dst, null, null );

t2 = System.currentTimeMillis()-t2;

g.dispose();

System.out.println(t1+" "+t2);

BufferedImage ti = dst;

dst = tmp;

tmp = ti;

tsrc = dst;

}

References:
	>drawImage speed (From: Jerry <email@hidden>)
	>Re: drawImage speed (From: Jeremy Wood <email@hidden>)
	>Re: drawImage speed (From: Jerry <email@hidden>)
	>Re: drawImage speed (From: Michael McDougall <email@hidden>)