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Update ColorSpace _HLG & _PQ to use 203 nit whitepoints

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Also cleans up identifying PQ & HLG transfer functions
using the same hack skia does of using negative G values
as an enum

Fixes: 272555335
Test: mapped out the curves

Change-Id: I2bd6cd0a234fdea701b85737a1378058f6c40a1b
This commit is contained in:
John Reck
2023-03-15 23:16:21 -04:00
parent 83b5bfc0eb
commit e4a3d6354a
2 changed files with 132 additions and 112 deletions
Download Patch File Download Diff File Expand all files Collapse all files

228
graphics/java/android/graphics/ColorSpace.java
View File

@@ -210,12 +210,16 @@ public abstract class ColorSpace {
private static final Rgb.TransferParameters SRGB_TRANSFER_PARAMETERS =
new Rgb.TransferParameters(1 / 1.055, 0.055 / 1.055, 1 / 12.92, 0.04045, 2.4);
// HLG transfer with an SDR whitepoint of 203 nits
private static final Rgb.TransferParameters BT2020_HLG_TRANSFER_PARAMETERS =
new Rgb.TransferParameters(2.0f, 2.0f, 1 / 0.17883277f,
0.28466892f, 0.5599107f, -11 / 12.0f, -3.0f, true);
new Rgb.TransferParameters(2.0, 2.0, 1 / 0.17883277, 0.28466892, 0.55991073,
-0.685490157, Rgb.TransferParameters.TYPE_HLGish);
// PQ transfer with an SDR whitepoint of 203 nits
private static final Rgb.TransferParameters BT2020_PQ_TRANSFER_PARAMETERS =
new Rgb.TransferParameters(-107 / 128.0f, 1.0f, 32 / 2523.0f,
2413 / 128.0f, -2392 / 128.0f, 8192 / 1305.0f, -2.0f, true);
new Rgb.TransferParameters(-1.555223, 1.860454, 32 / 2523.0, 2413 / 128.0,
-2392 / 128.0, 8192 / 1305.0, Rgb.TransferParameters.TYPE_PQish);
// See static initialization block next to #get(Named)
private static final ColorSpace[] sNamedColorSpaces = new ColorSpace[Named.values().length];
@@ -1651,8 +1655,8 @@ public abstract class ColorSpace {
BT2020_PRIMARIES,
ILLUMINANT_D65,
null,
x -> transferHLGOETF(x),
x -> transferHLGEOTF(x),
x -> transferHLGOETF(BT2020_HLG_TRANSFER_PARAMETERS, x),
x -> transferHLGEOTF(BT2020_HLG_TRANSFER_PARAMETERS, x),
0.0f, 1.0f,
BT2020_HLG_TRANSFER_PARAMETERS,
Named.BT2020_HLG.ordinal()
@@ -1663,8 +1667,8 @@ public abstract class ColorSpace {
BT2020_PRIMARIES,
ILLUMINANT_D65,
null,
x -> transferST2048OETF(x),
x -> transferST2048EOTF(x),
x -> transferST2048OETF(BT2020_PQ_TRANSFER_PARAMETERS, x),
x -> transferST2048EOTF(BT2020_PQ_TRANSFER_PARAMETERS, x),
0.0f, 1.0f,
BT2020_PQ_TRANSFER_PARAMETERS,
Named.BT2020_PQ.ordinal()
@@ -1672,44 +1676,58 @@ public abstract class ColorSpace {
sDataToColorSpaces.put(DataSpace.DATASPACE_BT2020_PQ, Named.BT2020_PQ.ordinal());
}
private static double transferHLGOETF(double x) {
double a = 0.17883277;
double b = 0.28466892;
double c = 0.55991073;
double r = 0.5;
return x > 1.0 ? a * Math.log(x - b) + c : r * Math.sqrt(x);
private static double transferHLGOETF(Rgb.TransferParameters params, double x) {
double sign = x < 0 ? -1.0 : 1.0;
x *= sign;
// Unpack the transfer params matching skia's packing & invert R, G, and a
final double R = 1.0 / params.a;
final double G = 1.0 / params.b;
final double a = 1.0 / params.c;
final double b = params.d;
final double c = params.e;
final double K = params.f + 1.0;
x /= K;
return sign * (x <= 1 ? R * Math.pow(x, G) : a * Math.log(x - b) + c);
}
private static double transferHLGEOTF(double x) {
double a = 0.17883277;
double b = 0.28466892;
double c = 0.55991073;
double r = 0.5;
return x <= 0.5 ? (x * x) / (r * r) : Math.exp((x - c) / a + b);
private static double transferHLGEOTF(Rgb.TransferParameters params, double x) {
double sign = x < 0 ? -1.0 : 1.0;
x *= sign;
// Unpack the transfer params matching skia's packing
final double R = params.a;
final double G = params.b;
final double a = params.c;
final double b = params.d;
final double c = params.e;
final double K = params.f + 1.0;
return K * sign * (x * R <= 1 ? Math.pow(x * R, G) : Math.exp((x - c) * a) + b);
}
private static double transferST2048OETF(double x) {
double m1 = (2610.0 / 4096.0) / 4.0;
double m2 = (2523.0 / 4096.0) * 128.0;
double c1 = (3424.0 / 4096.0);
double c2 = (2413.0 / 4096.0) * 32.0;
double c3 = (2392.0 / 4096.0) * 32.0;
private static double transferST2048OETF(Rgb.TransferParameters params, double x) {
double sign = x < 0 ? -1.0 : 1.0;
x *= sign;
double tmp = Math.pow(x, m1);
tmp = (c1 + c2 * tmp) / (1.0 + c3 * tmp);
return Math.pow(tmp, m2);
double a = -params.a;
double b = params.d;
double c = 1.0 / params.f;
double d = params.b;
double e = -params.e;
double f = 1.0 / params.c;
double tmp = Math.max(a + b * Math.pow(x, c), 0);
return sign * Math.pow(tmp / (d + e * Math.pow(x, c)), f);
}
private static double transferST2048EOTF(double x) {
double m1 = (2610.0 / 4096.0) / 4.0;
double m2 = (2523.0 / 4096.0) * 128.0;
double c1 = (3424.0 / 4096.0);
double c2 = (2413.0 / 4096.0) * 32.0;
double c3 = (2392.0 / 4096.0) * 32.0;
private static double transferST2048EOTF(Rgb.TransferParameters pq, double x) {
double sign = x < 0 ? -1.0 : 1.0;
x *= sign;
double tmp = Math.pow(Math.min(Math.max(x, 0.0), 1.0), 1.0 / m2);
tmp = Math.max(tmp - c1, 0.0) / (c2 - c3 * tmp);
return Math.pow(tmp, 1.0 / m1);
double tmp = Math.max(pq.a + pq.b * Math.pow(x, pq.c), 0);
return sign * Math.pow(tmp / (pq.d + pq.e * Math.pow(x, pq.c)), pq.f);
}
// Reciprocal piecewise gamma response
@@ -2276,6 +2294,10 @@ public abstract class ColorSpace {
* </ul>
*/
public static class TransferParameters {
private static final double TYPE_PQish = -2.0;
private static final double TYPE_HLGish = -3.0;
/** Variable \(a\) in the equation of the EOTF described above. */
public final double a;
/** Variable \(b\) in the equation of the EOTF described above. */
@@ -2291,56 +2313,8 @@ public abstract class ColorSpace {
/** Variable \(g\) in the equation of the EOTF described above. */
public final double g;
private TransferParameters(double a, double b, double c, double d, double e,
double f, double g, boolean nonCurveTransferParameters) {
// nonCurveTransferParameters correspondes to a "special" transfer function
if (!nonCurveTransferParameters) {
if (Double.isNaN(a) || Double.isNaN(b) || Double.isNaN(c)
|| Double.isNaN(d) || Double.isNaN(e) || Double.isNaN(f)
|| Double.isNaN(g)) {
throw new IllegalArgumentException("Parameters cannot be NaN");
}
// Next representable float after 1.0
// We use doubles here but the representation inside our native code
// is often floats
if (!(d >= 0.0 && d <= 1.0f + Math.ulp(1.0f))) {
throw new IllegalArgumentException(
"Parameter d must be in the range [0..1], " + "was " + d);
}
if (d == 0.0 && (a == 0.0 || g == 0.0)) {
throw new IllegalArgumentException(
"Parameter a or g is zero, the transfer function is constant");
}
if (d >= 1.0 && c == 0.0) {
throw new IllegalArgumentException(
"Parameter c is zero, the transfer function is constant");
}
if ((a == 0.0 || g == 0.0) && c == 0.0) {
throw new IllegalArgumentException("Parameter a or g is zero,"
+ " and c is zero, the transfer function is constant");
}
if (c < 0.0) {
throw new IllegalArgumentException(
"The transfer function must be increasing");
}
if (a < 0.0 || g < 0.0) {
throw new IllegalArgumentException(
"The transfer function must be positive or increasing");
}
}
this.a = a;
this.b = b;
this.c = c;
this.d = d;
this.e = e;
this.f = f;
this.g = g;
private static boolean isSpecialG(double g) {
return g == TYPE_PQish || g == TYPE_HLGish;
}
/**
@@ -2365,7 +2339,7 @@ public abstract class ColorSpace {
* @throws IllegalArgumentException If the parameters form an invalid transfer function
*/
public TransferParameters(double a, double b, double c, double d, double g) {
this(a, b, c, d, 0.0, 0.0, g, false);
this(a, b, c, d, 0.0, 0.0, g);
}
/**
@@ -2384,7 +2358,52 @@ public abstract class ColorSpace {
*/
public TransferParameters(double a, double b, double c, double d, double e,
double f, double g) {
this(a, b, c, d, e, f, g, false);
if (Double.isNaN(a) || Double.isNaN(b) || Double.isNaN(c)
|| Double.isNaN(d) || Double.isNaN(e) || Double.isNaN(f)
|| Double.isNaN(g)) {
throw new IllegalArgumentException("Parameters cannot be NaN");
}
if (!isSpecialG(g)) {
// Next representable float after 1.0
// We use doubles here but the representation inside our native code
// is often floats
if (!(d >= 0.0 && d <= 1.0f + Math.ulp(1.0f))) {
throw new IllegalArgumentException(
"Parameter d must be in the range [0..1], " + "was " + d);
}
if (d == 0.0 && (a == 0.0 || g == 0.0)) {
throw new IllegalArgumentException(
"Parameter a or g is zero, the transfer function is constant");
}
if (d >= 1.0 && c == 0.0) {
throw new IllegalArgumentException(
"Parameter c is zero, the transfer function is constant");
}
if ((a == 0.0 || g == 0.0) && c == 0.0) {
throw new IllegalArgumentException("Parameter a or g is zero,"
+ " and c is zero, the transfer function is constant");
}
if (c < 0.0) {
throw new IllegalArgumentException(
"The transfer function must be increasing");
}
if (a < 0.0 || g < 0.0) {
throw new IllegalArgumentException(
"The transfer function must be positive or increasing");
}
}
this.a = a;
this.b = b;
this.c = c;
this.d = d;
this.e = e;
this.f = f;
this.g = g;
}
@SuppressWarnings("SimplifiableIfStatement")
@@ -2424,6 +2443,17 @@ public abstract class ColorSpace {
result = 31 * result + (int) (temp ^ (temp >>> 32));
return result;
}
/**
* @hide
*/
private boolean isHLGish() {
return g == TYPE_HLGish;
}
private boolean isPQish() {
return g == TYPE_PQish;
}
}
@NonNull private final float[] mWhitePoint;
@@ -2460,11 +2490,10 @@ public abstract class ColorSpace {
float e, float f, float g, float[] xyz);
private static DoubleUnaryOperator generateOETF(TransferParameters function) {
boolean isNonCurveTransferParameters = function.equals(BT2020_HLG_TRANSFER_PARAMETERS)
|| function.equals(BT2020_PQ_TRANSFER_PARAMETERS);
if (isNonCurveTransferParameters) {
return function.f == 0.0 && function.g < 0.0 ? x -> transferHLGOETF(x)
: x -> transferST2048OETF(x);
if (function.isHLGish()) {
return x -> transferHLGOETF(function, x);
} else if (function.isPQish()) {
return x -> transferST2048OETF(function, x);
} else {
return function.e == 0.0 && function.f == 0.0
? x -> rcpResponse(x, function.a, function.b,
@@ -2475,11 +2504,10 @@ public abstract class ColorSpace {
}
private static DoubleUnaryOperator generateEOTF(TransferParameters function) {
boolean isNonCurveTransferParameters = function.equals(BT2020_HLG_TRANSFER_PARAMETERS)
|| function.equals(BT2020_PQ_TRANSFER_PARAMETERS);
if (isNonCurveTransferParameters) {
return function.f == 0.0 && function.g < 0.0 ? x -> transferHLGEOTF(x)
: x -> transferST2048EOTF(x);
if (function.isHLGish()) {
return x -> transferHLGEOTF(function, x);
} else if (function.isPQish()) {
return x -> transferST2048OETF(function, x);
} else {
return function.e == 0.0 && function.f == 0.0
? x -> response(x, function.a, function.b,

16
libs/hwui/jni/Graphics.cpp
View File

@@ -579,17 +579,9 @@ jobject GraphicsJNI::getColorSpace(JNIEnv* env, SkColorSpace* decodeColorSpace,
LOG_ALWAYS_FATAL_IF(res == skcms_TFType_HLGinvish || res == skcms_TFType_Invalid);
jobject params;
if (res == skcms_TFType_PQish || res == skcms_TFType_HLGish) {
params = env->NewObject(gTransferParameters_class, gTransferParameters_constructorMethodID,
transferParams.a, transferParams.b, transferParams.c,
transferParams.d, transferParams.e, transferParams.f,
transferParams.g, true);
} else {
params = env->NewObject(gTransferParameters_class, gTransferParameters_constructorMethodID,
transferParams.a, transferParams.b, transferParams.c,
transferParams.d, transferParams.e, transferParams.f,
transferParams.g, false);
}
params = env->NewObject(gTransferParameters_class, gTransferParameters_constructorMethodID,
transferParams.a, transferParams.b, transferParams.c, transferParams.d,
transferParams.e, transferParams.f, transferParams.g);
jfloatArray xyzArray = env->NewFloatArray(9);
jfloat xyz[9] = {
@@ -817,7 +809,7 @@ int register_android_graphics_Graphics(JNIEnv* env)
gTransferParameters_class = MakeGlobalRefOrDie(env, FindClassOrDie(env,
"android/graphics/ColorSpace$Rgb$TransferParameters"));
gTransferParameters_constructorMethodID =
GetMethodIDOrDie(env, gTransferParameters_class, "<init>", "(DDDDDDDZ)V");
GetMethodIDOrDie(env, gTransferParameters_class, "<init>", "(DDDDDDD)V");
gFontMetrics_class = FindClassOrDie(env, "android/graphics/Paint$FontMetrics");
gFontMetrics_class = MakeGlobalRefOrDie(env, gFontMetrics_class);