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Re: BufferedImage and int[] array

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On Friday, April 21, 2017 at 4:24:47 PM UTC-4, Eric Douglas wrote:
> With a real lack of comments in your code I'm not sure what each
> section is trying to accomplish.
> Taking a guess your invert method wants to turn the image upside down,
> I googled that and found this working code.

That code was all written last night and when I ran into the issue
with reading in a transparent enabled PNG file and it losing the
alpha channel I sort of stopped.

The algorithm is inverting the color.  This line reverses the color
of each pixel color channel:

    Line 275:
    pixels[offset] = rgba(255 - red, 255 - grn, 255 - blu, 0);
    http://www.libsf.org:8990/projects/LIB/repos/libsf/browse/king/keyboard_driver/gui/src/gui/BufferedImage3.java

The 255 - red computes the inverted color of the red channel, and
it repeats for green, blue, and sets the alpha channel to 0, which
is a bug and should be using the originally derived alp value on
line 220, once it's copied down into that function. :-)

I'll look at your solution.  I'm really thinking I don't need to
do anything other than load in the PNG as a 3-byte BGR format,
and then create a second PNG in the 4-byte ARGB format, and then
obtain WritableRaster objects and draw the image from one to the
other, which should handle the translation, and then delete the
3-byte BGR version.

Do you feel so inclined to write code to test that method out?
I only ask because you've been far more helpful than I would've
expected someone to be on Usenet. :-)  I plan on working on it
tonight.  I've only programmed in Java one time previously back
in 2011 on a project used to automate tests on hardware:

    Office Productivity Benchmark
    https://github.com/RickCHodgin/opbm

A lot of code written mostly from May-July 2011.  I'm sure it
has lots of errors in it, but I was on my own in trying to do
everything.  I used Stack Overflow and the javadoc help files.

That one was written in NetBeans 8.0 I believe.

Thank you,
Rick C. Hodgin

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BufferedImage and int[] array "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-21 08:28 -0700
  Re: BufferedImage and int[] array Eric Douglas <e.d.programmer@gmail.com> - 2017-04-21 08:54 -0700
    Re: BufferedImage and int[] array "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-21 09:03 -0700
      Re: BufferedImage and int[] array Eric Douglas <e.d.programmer@gmail.com> - 2017-04-21 10:41 -0700
        Re: BufferedImage and int[] array Eric Douglas <e.d.programmer@gmail.com> - 2017-04-21 10:46 -0700
        Re: BufferedImage and int[] array "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-21 11:13 -0700
          Re: BufferedImage and int[] array Eric Douglas <e.d.programmer@gmail.com> - 2017-04-21 12:12 -0700
          Re: BufferedImage and int[] array Eric Douglas <e.d.programmer@gmail.com> - 2017-04-21 13:24 -0700
            Re: BufferedImage and int[] array "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-21 13:37 -0700
              Re: BufferedImage and int[] array "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-21 13:40 -0700
              Re: BufferedImage and int[] array Eric Douglas <e.d.programmer@gmail.com> - 2017-04-21 13:54 -0700
                Re: BufferedImage and int[] array "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-21 13:59 -0700
              Re: BufferedImage and int[] array Eric Douglas <e.d.programmer@gmail.com> - 2017-04-21 13:58 -0700
                Re: BufferedImage and int[] array "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-21 14:06 -0700
  Re: BufferedImage and int[] array Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2017-04-22 11:28 -0500
    Re: BufferedImage and int[] array "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-24 07:33 -0700
      Re: BufferedImage and int[] array Eric Douglas <e.d.programmer@gmail.com> - 2017-04-24 08:04 -0700
    Re: BufferedImage and int[] array "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2017-04-24 08:17 -0700
      Re: BufferedImage and int[] array Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2017-04-24 11:25 -0500

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