How do create the palette? Brian
On Feb 15, 2016, at 3:39 AM, Jayathirth D V <jayathirth....@oracle.com> wrote: > Hi Jim, > > I performed performance analysis with white image so that all conditions are > checked in the new branch added. There is no major difference in time taken > before and after change. For each input I have tested time taken for > drawImage() API to convert from every format to Byte indexed type. For every > unique conversion test is run for 100 times. Please find the details: > > > Input > type > Min > before change > (ns) > Min > after change > (ns) > Max > before change > (ns) > Max > after change > (ns) > Average > before change > (ns) > Average > after > change > (ns) > INT_RGB > 523437 > 481491 > 1230724 > 1270440 > 789452 > 666144 > INT_ARGB > 500232 > 493986 > 12406307 > 1308816 > 793384 > 654015 > INT_ARGB_PRE > 500233 > 492201 > 1037057 > 981277 > 710250 > 699214 > INT_BGR > 537716 > 562706 > 1446703 > 2046001 > 862377 > 863256 > 3BYTE_BGR > 483275 > 481045 > 1181638 > 1384676 > 651427 > 580961 > 4BYTE_ABGR > 544410 > 499786 > 1292305 > 968783 > 690106 > 683881 > 4BYTE_ABGR_PRE > 504249 > 505588 > 1680086 > 1216445 > 756101 > 687750 > USHORT_565_RGB > 507818 > 505588 > 978153 > 1346746 > 652908 > 655782 > USHORT_555_RGB > 510496 > 509604 > 952272 > 1162004 > 650418 > 670811 > BYTE_GRAY > 481491 > 478367 > 1140585 > 1799231 > 691160 > 583250 > USHORT_GRAY > 506927 > 507373 > 1375751 > 1255267 > 728202 > 646902 > BYTE_BINARY > 541733 > 496217 > 1083466 > 959411 > 730527 > 728461 > > > The changes are tested with plain images having primary colors like RED, > GREEN, BLUE, BLACK and WHITE. > > Thanks, > Jay > > -----Original Message----- > From: Jim Graham > Sent: Friday, February 12, 2016 4:05 AM > To: Jayathirth D V; 2d-dev@openjdk.java.net; Philip Race; Prasanta Sadhukhan > Subject: Re: [OpenJDK 2D-Dev] Review Request for JDK-7116979 : Unexpected > pixel colour when converting images to TYPE_BYTE_INDEXED > > Hi Jayathirth, > > Did you do any performance analysis of this change? You are adding 6 tests > and multiple branches to per-pixel code. > > The effectiveness of this technique depends on the colormap that we have set > up. For the BufferedImage.TYPE_INDEXED constructor we produce a fairly nice > colormap, but if someone creates a custom colormap then the colors could be > anything. We create a decent inversion for just about any colormap, but that > doesn't mean that using only "the best match for solid red" will produce a > better result for a dithered approximation for red. It is true that if there > is a really good match for red then we should just use that, but if there are > no direct matches for red then we may choose to paint a red region with solid > orange even though there is another color in the colormap that when mixed > with orange approximates a red tone better. For example, if a colormap > contains no pure red, but > contains: > > 240, 20, 0 > 240, 0, 20 > > (I'm not sure if 20 is within our current error deltas that we use for > dithering, but this is an example not a test case.) > > Then using one of these alone might skew the color towards orange or purple. > Using both together in a dither pattern might keep the overall hue impression > as red, but with a small amount of noise in its saturation. > > What types of colormaps was this tested with? > > ...jim > > On 2/11/16 6:37 AM, Jayathirth D V wrote: > > Hi, > > > > _Please review the following fix in JDK9:_ > > > > __ > > > > Bug : https://bugs.openjdk.java.net/browse/JDK-7116979 > > > > Webrev : http://cr.openjdk.java.net/~jdv/7116979/webrev.00/ > > > > Issue : When Image containing black pixels are converted from any > > format to Byte Indexed format some of the pixels are not black. They > > are following pattern similar to dithering. > > > > Root cause : When we convert any format type to ByteIndexed we are > > adding Error delta values to R,G,B components using dithering indices. > > This is causing some pixels values to not point to proper index in > > color table. > > > > Solution : There is no need to add error delta for primary colors > > containing basic values in R,G,B components. Exclude such pixels from > > delta addition. > > > > Thanks, > > > > Jay > >
