The lcms 2.8 version added support for the cmsFLAGS_COPY_ALPHA flag: https://sourceforge.net/p/lcms/mailman/lcms-user/thread/001c01d1c0f3%2484a7cb30%248df76190%24%40ProDigitalSoftware.com/#msg35143398
which supports alpha channel transportation For our usage, it means we can use TYPE_4BYTE_ABGR and TYPE_INT_ARGB directly as a source and destination. Some numbers; converting new BufferedImage(3000, 3000, TYPE_INT_ARGB) from CS_sRGB to CS_CIEXYZ via op.filter(src, dst): //before the fix //Benchmark Mode Cnt Score Error Units //ColorAlphaConv.testFilter avgt 5 603,392 ± 12,932 ms/op //after the fix //Benchmark Mode Cnt Score Error Units //ColorAlphaConv.testFilter avgt 5 121,624 ± 0,906 ms/op But still slower than kcms //kcms jdk8u60 //Benchmark Mode Cnt Score Error Units //ColorAlphaConv.testFilter avgt 5 13,256 ± 0,169 ms/op ------------- Commit messages: - Initial fix Changes: https://git.openjdk.java.net/jdk/pull/3239/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3239&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8012229 Stats: 208 lines in 5 files changed: 195 ins; 2 del; 11 mod Patch: https://git.openjdk.java.net/jdk/pull/3239.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/3239/head:pull/3239 PR: https://git.openjdk.java.net/jdk/pull/3239
