Re: [Geotools-devel] GC merge (GEOT-873)

[Martin D. <mar...@no...>]

Simone Giannecchini a =E9crit :
> is there anyway me (or anyone else like aaime) can help you out with
> the merge. [...snip...]
>=20
> Plz, let me know how I can be of help, I am sure others will follow...


Thanks for your offer. I'm still porting ImageUtilities. Not yet finished=
, but I made some progress.=20
Commited latest bunch of work as of revision 20230.

I'm working only on module/coverage. I would let the merge of other modul=
es (including module/main)=20
to other peoples if possible. Once the merge is finished, I would suggest=
 to work directly on trunk,=20
especially if future work are mostly bug fixes, unless there is other maj=
or work undergoing.

All new methods in ImageUtilities were moved in org.geotools.image.ImageW=
orker (a new class). I have=20
not yet finished it. But if you want, you could copy ImageWorker from tru=
nk to the coverage branch=20
and start changing the references to ImageUtilities to ImageWorker in the=
 code. And of course test,=20
test and test, since I made my best but have probably done some mistakes =
there and there. Note: I=20
have added a convenience method for testing. More detais below.



Differences between ImageWorker and ImageUtilities:
---------------------------------------------------

   * Instead of a bunch of static methods, we create one ImageWorker inst=
ance with the image we
     want to work on. From this point, we control various methods like "f=
orceIndexColorModel()"
     for applying operations on the image. Advantages are:

     - We have more control on the operation process (including tile cach=
e control) through
       ImageWorker.setRenderingHint(...). So we can control the whole set=
 of rendering hints,
       compared to a few boolean parameters in the static methods.

     - The static methods were expecting and returning a mix of PlanarIma=
ge or RenderedOp
       objects. ImageWorker allow to access to the image result through g=
etRenderedImage(),
       getPlanarImage() or getRenderedOperation(), at user choice. For us=
ers who just want
       a RenderedImage, the above choice allows them to get that image wi=
thout creating an
       unecessary "Null" operation.

   * The static methods had a some duplicated code, which I tried to redu=
ce. Some methods
     also had hard-coded values (e.g. addTransparency2IndexColorModel), w=
hich I tried to
     avoid as well.

   * Sometime the algorithm has been significatively changed. For example
     ImageUtilities.addTransparency2IndexColorModel(...) tries to set the=
 transparent pixel
     value using the "Add" operation, while I believe that the intend was=
 a combinaison of
     "And" and "Or" operations. I reimplemented this method using such "A=
nd" / "Or", and
     took the occasion to factor out a part of the code as a new "mask" m=
ethod.



Testing
-------------------------------------------------
I have not yet tested all methods, but I tested some of them. Try the fol=
lowing from the command line:

     java org.geotools.image.ImageWorker PP20000102.png -operation binari=
ze

Where PP20000102.png should be some image on yours disk. This main method=
 actually do nothing more=20
than loading the image, applying the specified operation and invoking the=
 following method:

     imageWorker.show();

The 'show()' method will display a widget with a buch of informations for=
 browsing the operation=20
chain. This is a kind of "toString()" method for debugging purpose, but m=
uch more elaborated. Note:=20
Use a raisonable image size - this widget is for debugging the operation =
chain, not for testing its=20
capacity to render large images.

Note: ImageWorker.show() requires "gt2-widgets-swing.jar" to be in the cl=
asspath. For all other=20
methods, this dependency is of course not needed.


Javadoc:
-------------------------------------------------
http://javadoc.geotools.fr/snapshot/org/geotools/image/ImageWorker.html





Mapping from ImageUtilities to ImageWorker
(I admit that using ImageWorker is more verbove):
-------------------------------------------------

Old:
     image =3D ImageUtilities.rescale2Byte(image);

Proposed replacement:
     ImageWorker worker =3D new ImageWorker(image);
     worker.rescaleToBytes();
     image =3D worker.getPlanarImage();

-------------------------------------------------------------

Old:
     image =3D ImageUtilities.RGBIndexColorModel(image);

Proposed replacement:
     ImageWorker worker =3D new ImageWorker(image);
     worker.forceIndexColorModel();
     image =3D worker.getPlanarImage();

-------------------------------------------------------------

Old:
     image =3D ImageUtilities.direct2ComponentColorModel(image);
     image =3D ImageUtilities.reformatColorModel2ComponentColorModel(imag=
e);

Proposed replacement:
     ImageWorker worker =3D new ImageWorker(image);
     worker.forceComponentColorModel();
     image =3D worker.getPlanarImage();

-------------------------------------------------------------

Old:
     image =3D ImageUtilities.binarizeImageExt(image, threshold, cacheMe)=
;

Proposed replacement:
     ImageWorker worker =3D new ImageWorker(image);
     if (!cacheMe) {
         worker.setRenderingHint(JAI.KEY_TILE_CACHE, null);
     }
     worker.binarize(threshold);
     image =3D worker.getRenderedOperation();

-------------------------------------------------------------

Old:
     image =3D ImageUtilities.roiExt(image, threshold, cacheMe);

Proposed replacement:
     ImageWorker worker =3D new ImageWorker(image);
     if (!cacheMe) {
         worker.setRenderingHint(JAI.KEY_TILE_CACHE, null);
     }
     worker.binarize(threshold);
     image =3D worker.getImageAsROI();

-------------------------------------------------------------

Old:
     image =3D ImageUtilities.bandCombineSimple(image, cacheMe);
     image =3D ImageUtilities.convertIHS(image, cacheMe);

Proposed replacement:
     ImageWorker worker =3D new ImageWorker(image);
     if (!cacheMe) {
         worker.setRenderingHint(JAI.KEY_TILE_CACHE, null);
     }
     worker.intensity();
     image =3D worker.getRenderedOperation();

-------------------------------------------------------------

Old:
     image =3D ImageUtilities.selectBand(image, threshold, cacheMe);

Proposed replacement:
     ImageWorker worker =3D new ImageWorker(image);
     if (!cacheMe) {
         worker.setRenderingHint(JAI.KEY_TILE_CACHE, null);
     }
     worker.retainFirstBand(threshold);
     image =3D worker.getRenderedOperation();

-------------------------------------------------------------

Old:
     image =3D ImageUtilities.addTransparency2IndexColorModel(image, alph=
a, optimizeForGIF);

Proposed replacement:
     ImageWorker worker =3D new ImageWorker(image);
     if (optimizeForGIF) {
         worker.setRenderingHint(ImageWorker.TILING_ALLOWED, Boolean.FALS=
E);
     }
     worker.addTransparencyToIndexColorModel(threshold);
     image =3D worker.getRenderedOperation();