chiuki / android-graphics-demo Goto Github PK

Hello,
I have used this code snippet,how i can reduce black color over here.

 ColorMatrix colorMatrix = new ColorMatrix();
        colorMatrix.setSaturation(0);
        float brightness = (float)(bar.getProgress());//it can be 0-128
        float m = 205f;
        float t = -255*brightness;
        ColorMatrix threshold = new ColorMatrix(new float[] {
                m, 1, 0, 1, t,
                0, m, 1, 1, t,
                1, 0, m, 1, t,
                0, 1, 0, 1, 0
        });

After above implementation image become too black.

2019-01-17 15:15:48.875 6291-6291/com.sqisland.android.graphics_demo A/libc: Fatal signal 11 (SIGSEGV), code 1, fault addr 0x704c800000 in tid 6291 (d.graphics_demo), pid 6291 (d.graphics_demo)
2019-01-17 15:15:48.956 6383-6383/? A/DEBUG: *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
2019-01-17 15:15:48.956 6383-6383/? A/DEBUG: Build fingerprint: 'Nokia/TA-1000_00CN/D1C:8.1.0/OPR1.170623.026/00CN_5_62G:user/release-keys'
2019-01-17 15:15:48.956 6383-6383/? A/DEBUG: Revision: '0'
2019-01-17 15:15:48.956 6383-6383/? A/DEBUG: ABI: 'arm64'
2019-01-17 15:15:48.956 6383-6383/? A/DEBUG: pid: 6291, tid: 6291, name: d.graphics_demo >>> com.sqisland.android.graphics_demo <<<
2019-01-17 15:15:48.956 6383-6383/? A/DEBUG: signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x704c800000
2019-01-17 15:15:48.956 6383-6383/? A/DEBUG: x0 000000704c7fffa0 x1 3131313131313131 x2 3131313131313131 x3 000000704c7fffa0
2019-01-17 15:15:48.956 6383-6383/? A/DEBUG: x4 000000704dbf3083 x5 000000704c800013 x6 3131313131313131 x7 3131313131313131
2019-01-17 15:15:48.956 6383-6383/? A/DEBUG: x8 3131313131313131 x9 3131313131313131 x10 3131313131313131 x11 3831313131313131
2019-01-17 15:15:48.957 6383-6383/? A/DEBUG: x12 3131313131313131 x13 3131313131313131 x14 0000000000000008 x15 000000704da0c110
2019-01-17 15:15:48.957 6383-6383/? A/DEBUG: x16 00000070e8c569a0 x17 00000070ead78770 x18 000000704db73d81 x19 0000000000000074
2019-01-17 15:15:48.957 6383-6383/? A/DEBUG: x20 000000704da34900 x21 000000704c7fffa0 x22 000000704dbf3010 x23 0000000000000073
2019-01-17 15:15:48.957 6383-6383/? A/DEBUG: x24 000000000000001e x25 0000000000000074 x26 0000007fc3280df8 x27 0000007fc3281238
2019-01-17 15:15:48.957 6383-6383/? A/DEBUG: x28 0000000000000010 x29 0000007fc3281320 x30 00000070e873195c
2019-01-17 15:15:48.957 6383-6383/? A/DEBUG: sp 0000007fc3280cf0 pc 00000070ead788d0 pstate 0000000080000000
2019-01-17 15:15:49.497 6383-6383/? A/DEBUG: backtrace:
2019-01-17 15:15:49.498 6383-6383/? A/DEBUG: #00 pc 000000000001c8d0 /system/lib64/libc.so (memcpy+352)
2019-01-17 15:15:49.498 6383-6383/? A/DEBUG: #1 pc 0000000000304958 /system/lib64/libskia.so (SkScalerContext::getImage(SkGlyph const&)+3692)
2019-01-17 15:15:49.498 6383-6383/? A/DEBUG: #2 pc 0000000000286f30 /system/lib64/libskia.so (SkGlyphCache::findImage(SkGlyph const&)+84)
2019-01-17 15:15:49.498 6383-6383/? A/DEBUG: #3 pc 000000000027a874 /system/lib64/libskia.so (DrawOneGlyph::operator()(SkGlyph const&, SkPoint, SkPoint)+392)
2019-01-17 15:15:49.498 6383-6383/? A/DEBUG: #04 pc 000000000027b7a8 /system/lib64/libskia.so (ZN19SkFindAndPlaceGlyph26GlyphFindAndPlaceFullPixelIR12DrawOneGlyphLN7SkPaint5AlignE0ELNS_13SelectKerningE0EE20findAndPositionGlyphEPPKc7SkPointS2+80)
2019-01-17 15:15:49.498 6383-6383/? A/DEBUG: #05 pc 0000000000279d3c /system/lib64/libskia.so

The screens shots in your demo talk actually applies filters to the lena image you have in drawable resource.
However when i tried the same code with the same image on my pixle2xl the sharpen and the original looks same. Similarly the blur and original image looks same.
I have tried this with multiple images and it looks all the same.

Demo Video : https://drive.google.com/open?id=1kiMVmJ08D0sxREOGuHRBzpI__Ga_BWsx
Pixel2 emualtor.

I have also read blogs and talks by rebecca franks on renderscript which is available on youtube.
https://www.youtube.com/watch?v=hUHaJIXWc-k&ab_channel=GDGLviv.

Also is there any hint on how these filters values are got ie the matrix values. I know its available online. But would like to know more if you can point me to some resources.
Your talk is old but very relevant and helpful. Thanks.