| Message ID | 20251210005354.44726-11-bryan.odonoghue@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series |
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| Related | show |
Bryan O'Donoghue <bryan.odonoghue@linaro.org> writes: > Apply contrast after black-level and CCM operations. > > Suggested-by: Milan Zamazal <mzamazal@redhat.com> > Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> > --- > src/libcamera/shaders/bayer_1x_packed.frag | 19 +++++++++++++++++++ > src/libcamera/shaders/bayer_unpacked.frag | 19 +++++++++++++++++++ > 2 files changed, 38 insertions(+) > > diff --git a/src/libcamera/shaders/bayer_1x_packed.frag b/src/libcamera/shaders/bayer_1x_packed.frag > index 77d9fbfa7..eea237dfc 100644 > --- a/src/libcamera/shaders/bayer_1x_packed.frag > +++ b/src/libcamera/shaders/bayer_1x_packed.frag > @@ -68,6 +68,19 @@ uniform sampler2D tex_y; > uniform mat3 ccm; > uniform vec3 blacklevel; > uniform float gamma; > +uniform float contrast; > + > +float apply_contrast(float value) > +{ > + // Convert 0..2 contrast to 0..infinity; avoid actual infinity at tan(pi/2) > + float contrastExp = tan(clamp(contrast * 0.78539816339744830962, 0.0, 1.5707963267948966 - 0.00001)); Can this be moved to the top level? (The same for the unpacked shader.) > + > + // Apply simple S-curve > + if (value < 0.5) > + return 0.5 * pow(value / 0.5, contrastExp); > + else > + return 1.0 - 0.5 * pow((1.0 - value) / 0.5, contrastExp); > +} > > void main(void) > { > @@ -261,6 +274,12 @@ void main(void) > rgb.g = (rin * ccm[1][0]) + (gin * ccm[1][1]) + (bin * ccm[1][2]); > rgb.b = (rin * ccm[2][0]) + (gin * ccm[2][1]) + (bin * ccm[2][2]); > > + // Contrast > + rgb = clamp(rgb, 0.0, 1.0); > + rgb.r = apply_contrast(rgb.r); > + rgb.g = apply_contrast(rgb.g); > + rgb.b = apply_contrast(rgb.b); > + > /* Apply gamma after colour correction */ > rgb = pow(rgb, vec3(gamma)); > > diff --git a/src/libcamera/shaders/bayer_unpacked.frag b/src/libcamera/shaders/bayer_unpacked.frag > index aba11a87f..1226fe075 100644 > --- a/src/libcamera/shaders/bayer_unpacked.frag > +++ b/src/libcamera/shaders/bayer_unpacked.frag > @@ -27,6 +27,19 @@ varying vec4 xCoord; > uniform mat3 ccm; > uniform vec3 blacklevel; > uniform float gamma; > +uniform float contrast; > + > +float apply_contrast(float value) > +{ > + // Convert 0..2 contrast to 0..infinity; avoid actual infinity at tan(pi/2) > + float contrastExp = tan(clamp(contrast * 0.78539816339744830962, 0.0, 1.5707963267948966 - 0.00001)); > + > + // Apply simple S-curve > + if (value < 0.5) > + return 0.5 * pow(value / 0.5, contrastExp); > + else > + return 1.0 - 0.5 * pow((1.0 - value) / 0.5, contrastExp); > +} > > void main(void) { > vec3 rgb; > @@ -156,6 +169,12 @@ void main(void) { > rgb.g = (rin * ccm[1][0]) + (gin * ccm[1][1]) + (bin * ccm[1][2]); > rgb.b = (rin * ccm[2][0]) + (gin * ccm[2][1]) + (bin * ccm[2][2]); > > + // Contrast > + rgb = clamp(rgb, 0.0, 1.0); > + rgb.r = apply_contrast(rgb.r, contrast); > + rgb.g = apply_contrast(rgb.g, contrast); > + rgb.b = apply_contrast(rgb.b, contrast); > + > /* Apply gamma after colour correction */ > rgb = pow(rgb, vec3(gamma));
diff --git a/src/libcamera/shaders/bayer_1x_packed.frag b/src/libcamera/shaders/bayer_1x_packed.frag index 77d9fbfa7..eea237dfc 100644 --- a/src/libcamera/shaders/bayer_1x_packed.frag +++ b/src/libcamera/shaders/bayer_1x_packed.frag @@ -68,6 +68,19 @@ uniform sampler2D tex_y; uniform mat3 ccm; uniform vec3 blacklevel; uniform float gamma; +uniform float contrast; + +float apply_contrast(float value) +{ + // Convert 0..2 contrast to 0..infinity; avoid actual infinity at tan(pi/2) + float contrastExp = tan(clamp(contrast * 0.78539816339744830962, 0.0, 1.5707963267948966 - 0.00001)); + + // Apply simple S-curve + if (value < 0.5) + return 0.5 * pow(value / 0.5, contrastExp); + else + return 1.0 - 0.5 * pow((1.0 - value) / 0.5, contrastExp); +} void main(void) { @@ -261,6 +274,12 @@ void main(void) rgb.g = (rin * ccm[1][0]) + (gin * ccm[1][1]) + (bin * ccm[1][2]); rgb.b = (rin * ccm[2][0]) + (gin * ccm[2][1]) + (bin * ccm[2][2]); + // Contrast + rgb = clamp(rgb, 0.0, 1.0); + rgb.r = apply_contrast(rgb.r); + rgb.g = apply_contrast(rgb.g); + rgb.b = apply_contrast(rgb.b); + /* Apply gamma after colour correction */ rgb = pow(rgb, vec3(gamma)); diff --git a/src/libcamera/shaders/bayer_unpacked.frag b/src/libcamera/shaders/bayer_unpacked.frag index aba11a87f..1226fe075 100644 --- a/src/libcamera/shaders/bayer_unpacked.frag +++ b/src/libcamera/shaders/bayer_unpacked.frag @@ -27,6 +27,19 @@ varying vec4 xCoord; uniform mat3 ccm; uniform vec3 blacklevel; uniform float gamma; +uniform float contrast; + +float apply_contrast(float value) +{ + // Convert 0..2 contrast to 0..infinity; avoid actual infinity at tan(pi/2) + float contrastExp = tan(clamp(contrast * 0.78539816339744830962, 0.0, 1.5707963267948966 - 0.00001)); + + // Apply simple S-curve + if (value < 0.5) + return 0.5 * pow(value / 0.5, contrastExp); + else + return 1.0 - 0.5 * pow((1.0 - value) / 0.5, contrastExp); +} void main(void) { vec3 rgb; @@ -156,6 +169,12 @@ void main(void) { rgb.g = (rin * ccm[1][0]) + (gin * ccm[1][1]) + (bin * ccm[1][2]); rgb.b = (rin * ccm[2][0]) + (gin * ccm[2][1]) + (bin * ccm[2][2]); + // Contrast + rgb = clamp(rgb, 0.0, 1.0); + rgb.r = apply_contrast(rgb.r, contrast); + rgb.g = apply_contrast(rgb.g, contrast); + rgb.b = apply_contrast(rgb.b, contrast); + /* Apply gamma after colour correction */ rgb = pow(rgb, vec3(gamma));
Apply contrast after black-level and CCM operations. Suggested-by: Milan Zamazal <mzamazal@redhat.com> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> --- src/libcamera/shaders/bayer_1x_packed.frag | 19 +++++++++++++++++++ src/libcamera/shaders/bayer_unpacked.frag | 19 +++++++++++++++++++ 2 files changed, 38 insertions(+)