| /************************************************************************** |
| * |
| * Copyright 2009 Younes Manton. |
| * All Rights Reserved. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the |
| * "Software"), to deal in the Software without restriction, including |
| * without limitation the rights to use, copy, modify, merge, publish, |
| * distribute, sub license, and/or sell copies of the Software, and to |
| * permit persons to whom the Software is furnished to do so, subject to |
| * the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the |
| * next paragraph) shall be included in all copies or substantial portions |
| * of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. |
| * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR |
| * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| * |
| **************************************************************************/ |
| |
| #include "util/u_math.h" |
| #include "util/u_debug.h" |
| |
| #include "vl_csc.h" |
| |
| /* |
| * Color space conversion formulas |
| * |
| * To convert YCbCr to RGB, |
| * vec4 ycbcr, rgb |
| * mat44 csc |
| * rgb = csc * ycbcr |
| * |
| * To calculate the color space conversion matrix csc with ProcAmp adjustments, |
| * mat44 csc, cstd, procamp, bias |
| * csc = cstd * (procamp * bias) |
| * |
| * Where cstd is a matrix corresponding to one of the color standards (BT.601, BT.709, etc) |
| * adjusted for the kind of YCbCr -> RGB mapping wanted (1:1, full), |
| * bias is a matrix corresponding to the kind of YCbCr -> RGB mapping wanted (1:1, full) |
| * |
| * To calculate procamp, |
| * mat44 procamp, hue, saturation, brightness, contrast |
| * procamp = brightness * (saturation * (contrast * hue)) |
| * Alternatively, |
| * procamp = saturation * (brightness * (contrast * hue)) |
| * |
| * contrast |
| * [ c, 0, 0, 0] |
| * [ 0, c, 0, 0] |
| * [ 0, 0, c, 0] |
| * [ 0, 0, 0, 1] |
| * |
| * brightness |
| * [ 1, 0, 0, b/c] |
| * [ 0, 1, 0, 0] |
| * [ 0, 0, 1, 0] |
| * [ 0, 0, 0, 1] |
| * |
| * saturation |
| * [ 1, 0, 0, 0] |
| * [ 0, s, 0, 0] |
| * [ 0, 0, s, 0] |
| * [ 0, 0, 0, 1] |
| * |
| * hue |
| * [ 1, 0, 0, 0] |
| * [ 0, cos(h), sin(h), 0] |
| * [ 0, -sin(h), cos(h), 0] |
| * [ 0, 0, 0, 1] |
| * |
| * procamp |
| * [ c, 0, 0, b] |
| * [ 0, c*s*cos(h), c*s*sin(h), 0] |
| * [ 0, -c*s*sin(h), c*s*cos(h), 0] |
| * [ 0, 0, 0, 1] |
| * |
| * bias |
| * [ 1, 0, 0, ybias] |
| * [ 0, 1, 0, cbbias] |
| * [ 0, 0, 1, crbias] |
| * [ 0, 0, 0, 1] |
| * |
| * csc |
| * [ c*cstd[ 0], c*cstd[ 1]*s*cos(h) - c*cstd[ 2]*s*sin(h), c*cstd[ 2]*s*cos(h) + c*cstd[ 1]*s*sin(h), cstd[ 3] + cstd[ 0]*(b + c*ybias) + cstd[ 1]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[ 2]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))] |
| * [ c*cstd[ 4], c*cstd[ 5]*s*cos(h) - c*cstd[ 6]*s*sin(h), c*cstd[ 6]*s*cos(h) + c*cstd[ 5]*s*sin(h), cstd[ 7] + cstd[ 4]*(b + c*ybias) + cstd[ 5]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[ 6]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))] |
| * [ c*cstd[ 8], c*cstd[ 9]*s*cos(h) - c*cstd[10]*s*sin(h), c*cstd[10]*s*cos(h) + c*cstd[ 9]*s*sin(h), cstd[11] + cstd[ 8]*(b + c*ybias) + cstd[ 9]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[10]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))] |
| * [ c*cstd[12], c*cstd[13]*s*cos(h) - c*cstd[14]*s*sin(h), c*cstd[14]*s*cos(h) + c*cstd[13]*s*sin(h), cstd[15] + cstd[12]*(b + c*ybias) + cstd[13]*(c*cbbias*s*cos(h) + c*crbias*s*sin(h)) + cstd[14]*(c*crbias*s*cos(h) - c*cbbias*s*sin(h))] |
| */ |
| |
| /* |
| * Converts ITU-R BT.601 YCbCr pixels to RGB pixels where: |
| * Y is in [16,235], Cb and Cr are in [16,240] |
| * R, G, and B are in [16,235] |
| */ |
| static const vl_csc_matrix bt_601 = |
| { |
| { 1.0f, 0.0f, 1.371f, 0.0f, }, |
| { 1.0f, -0.336f, -0.698f, 0.0f, }, |
| { 1.0f, 1.732f, 0.0f, 0.0f, } |
| }; |
| |
| /* |
| * Converts ITU-R BT.709 YCbCr pixels to RGB pixels where: |
| * Y is in [16,235], Cb and Cr are in [16,240] |
| * R, G, and B are in [16,235] |
| */ |
| static const vl_csc_matrix bt_709 = |
| { |
| { 1.0f, 0.0f, 1.540f, 0.0f, }, |
| { 1.0f, -0.183f, -0.459f, 0.0f, }, |
| { 1.0f, 1.816f, 0.0f, 0.0f, } |
| }; |
| |
| /* |
| * Converts SMPTE 240M YCbCr pixels to RGB pixels where: |
| * Y is in [16,235], Cb and Cr are in [16,240] |
| * R, G, and B are in [16,235] |
| */ |
| static const vl_csc_matrix smpte240m = |
| { |
| { 1.0f, 0.0f, 1.541f, 0.0f, }, |
| { 1.0f, -0.221f, -0.466f, 0.0f, }, |
| { 1.0f, 1.785f, 0.0f, 0.0f, } |
| }; |
| |
| static const vl_csc_matrix bt_709_rev = { |
| { 0.183f, 0.614f, 0.062f, 0.0625f}, |
| {-0.101f, -0.338f, 0.439f, 0.5f }, |
| { 0.439f, -0.399f, -0.040f, 0.5f } |
| }; |
| |
| static const vl_csc_matrix identity = |
| { |
| { 1.0f, 0.0f, 0.0f, 0.0f, }, |
| { 0.0f, 1.0f, 0.0f, 0.0f, }, |
| { 0.0f, 0.0f, 1.0f, 0.0f, } |
| }; |
| |
| const struct vl_procamp vl_default_procamp = { |
| 0.0f, /* brightness */ |
| 1.0f, /* contrast */ |
| 1.0f, /* saturation */ |
| 0.0f /* hue */ |
| }; |
| |
| void vl_csc_get_matrix(enum VL_CSC_COLOR_STANDARD cs, |
| struct vl_procamp *procamp, |
| bool full_range, |
| vl_csc_matrix *matrix) |
| { |
| float cbbias = -128.0f/255.0f; |
| float crbias = -128.0f/255.0f; |
| |
| const struct vl_procamp *p = procamp ? procamp : &vl_default_procamp; |
| float c = p->contrast; |
| float s = p->saturation; |
| float b = p->brightness; |
| float h = p->hue; |
| float x, y; |
| |
| const vl_csc_matrix *cstd; |
| |
| if (full_range) { |
| c *= 1.164f; /* Adjust for the y range */ |
| b *= 1.164f; /* Adjust for the y range */ |
| b -= c * 16.0f / 255.0f; /* Adjust for the y bias */ |
| } |
| |
| /* Parameter substitutions */ |
| x = c * s * cosf(h); |
| y = c * s * sinf(h); |
| |
| assert(matrix); |
| |
| switch (cs) { |
| case VL_CSC_COLOR_STANDARD_BT_601: |
| cstd = &bt_601; |
| break; |
| case VL_CSC_COLOR_STANDARD_BT_709: |
| cstd = &bt_709; |
| break; |
| case VL_CSC_COLOR_STANDARD_SMPTE_240M: |
| cstd = &smpte240m; |
| break; |
| case VL_CSC_COLOR_STANDARD_BT_709_REV: |
| memcpy(matrix, bt_709_rev, sizeof(vl_csc_matrix)); |
| return; |
| case VL_CSC_COLOR_STANDARD_IDENTITY: |
| default: |
| assert(cs == VL_CSC_COLOR_STANDARD_IDENTITY); |
| memcpy(matrix, identity, sizeof(vl_csc_matrix)); |
| return; |
| } |
| |
| (*matrix)[0][0] = c * (*cstd)[0][0]; |
| (*matrix)[0][1] = (*cstd)[0][1] * x - (*cstd)[0][2] * y; |
| (*matrix)[0][2] = (*cstd)[0][2] * x + (*cstd)[0][1] * y; |
| (*matrix)[0][3] = (*cstd)[0][3] + (*cstd)[0][0] * b + |
| (*cstd)[0][1] * (x * cbbias + y * crbias) + |
| (*cstd)[0][2] * (x * crbias - y * cbbias); |
| |
| (*matrix)[1][0] = c * (*cstd)[1][0]; |
| (*matrix)[1][1] = (*cstd)[1][1] * x - (*cstd)[1][2] * y; |
| (*matrix)[1][2] = (*cstd)[1][2] * x + (*cstd)[1][1] * y; |
| (*matrix)[1][3] = (*cstd)[1][3] + (*cstd)[1][0] * b + |
| (*cstd)[1][1] * (x * cbbias + y * crbias) + |
| (*cstd)[1][2] * (x * crbias - y * cbbias); |
| |
| (*matrix)[2][0] = c * (*cstd)[2][0]; |
| (*matrix)[2][1] = (*cstd)[2][1] * x - (*cstd)[2][2] * y; |
| (*matrix)[2][2] = (*cstd)[2][2] * x + (*cstd)[2][1] * y; |
| (*matrix)[2][3] = (*cstd)[2][3] + (*cstd)[2][0] * b + |
| (*cstd)[2][1] * (x * cbbias + y * crbias) + |
| (*cstd)[2][2] * (x * crbias - y * cbbias); |
| } |