Vectorscope.
- The basis matrix for converting RGB to YUV is:
+ The basis matrix for converting RGB to YUV is
+ (in this example for calculating the YUV value of red):
mRgb2Yuv = r =
divide the conversion values by 255 previously, e.g. in
GNU octave.
+
+ The basis matrix for converting RGB to YPbPr is:
+
+mRgb2YPbPr = r =
+
+ 0.299000 0.587000 0.114000 1.0000
+ -0.168736 -0.331264 0.500000 x 0.0000
+ 0.500000 -0.418688 -0.081312 0.0000
+
+
+
+ Note that YUV and YPbPr are not the same.
+ * YUV is used for analog transfer of PAL/NTSC
+ * YPbPr is used for analog transfer of YCbCr sources
+ like DVD/DVB.
+ It does _not_ matter for the Vectorscope what color space
+ the input video is; The used color space is just a tool
+ to visualize the hue. The difference is merely that the
+ scope looks slightly different when choosing the respectively
+ other color space; The way the Vectorscope works stays the same.
+
+ YCbCr is basically YPbPr for digital use (it is defined
+ on a range of {16,219} for Y and {16,240} for Cb/Cr
+ components).
+
+
+
+
See also:
+ http://www.poynton.com/ColorFAQ.html
http://de.wikipedia.org/wiki/Vektorskop
http://www.elektroniktutor.de/techno/vektskop.html
*/
#include <math.h>
-#include <QDebug>
#include <QImage>
#include "vectorscopegenerator.h"
}
QImage VectorscopeGenerator::calculateVectorscope(const QSize &vectorscopeSize, const QImage &image, const float &gain,
- const VectorscopeGenerator::PaintMode &paintMode, const bool&,
- const uint &accelFactor) const
+ const VectorscopeGenerator::PaintMode &paintMode,
+ const VectorscopeGenerator::ColorSpace &colorSpace,
+ bool, uint accelFactor) const
{
- if (vectorscopeSize.width() <= 0 || vectorscopeSize.height() <= 0) {
+ if (vectorscopeSize.width() <= 0 || vectorscopeSize.height() <= 0 || image.width() <= 0 || image.height() <= 0) {
// Invalid size
return QImage();
}
int r,g,b;
double dy, dr, dg, db, dmax;
- double y,u,v;
+ double /*y,*/ u, v;
QPoint pt;
QRgb px;
- const int stepsize = 4*accelFactor;
+ const int stepsize = image.depth() / 8 * accelFactor;
// Just an average for the number of image pixels per scope pixel.
// NOTE: byteCount() has to be replaced by (img.bytesPerLine()*img.height()) for Qt 4.5 to compile, see: http://doc.trolltech.org/4.6/qimage.html#bytesPerLine
- double avgPxPerPx = (double) 4*(image.bytesPerLine()*image.height())/scope.size().width()/scope.size().height()/accelFactor;
- qDebug() << "Expecting " << avgPxPerPx << " pixels per pixel.";
+ double avgPxPerPx = (double) image.depth() / 8 *(image.bytesPerLine()*image.height())/scope.size().width()/scope.size().height()/accelFactor;
for (int i = 0; i < (image.bytesPerLine()*image.height()); i+= stepsize) {
QRgb *col = (QRgb *) bits;
g = qGreen(*col);
b = qBlue(*col);
- y = (double) 0.001173 * r +0.002302 * g +0.0004471* b;
- u = (double) -0.0005781* r -0.001135 * g +0.001713 * b;
- v = (double) 0.002411 * r -0.002019 * g -0.0003921* b;
+ switch (colorSpace) {
+ case VectorscopeGenerator::ColorSpace_YUV:
+// y = (double) 0.001173 * r +0.002302 * g +0.0004471* b;
+ u = (double) -0.0005781* r -0.001135 * g +0.001713 * b;
+ v = (double) 0.002411 * r -0.002019 * g -0.0003921* b;
+ break;
+ case VectorscopeGenerator::ColorSpace_YPbPr:
+ default:
+// y = (double) 0.001173 * r +0.002302 * g +0.0004471* b;
+ u = (double) -0.0006671* r -0.001299 * g +0.0019608* b;
+ v = (double) 0.001961 * r -0.001642 * g -0.0003189* b;
+ break;
+ }
+
pt = mapToCircle(vectorscopeSize, QPointF(SCALING*gain*u, SCALING*gain*v));
// see yuvColorWheel
dy = 128; // Default Y value. Lower = darker.
- // Calculate the RGB values from YUV
- dr = dy + 290.8*v;
- dg = dy - 100.6*u - 148*v;
- db = dy + 517.2*u;
+ // Calculate the RGB values from YUV/YPbPr
+ switch (colorSpace) {
+ case VectorscopeGenerator::ColorSpace_YUV:
+ dr = dy + 290.8*v;
+ dg = dy - 100.6*u - 148*v;
+ db = dy + 517.2*u;
+ break;
+ case VectorscopeGenerator::ColorSpace_YPbPr:
+ default:
+ dr = dy + 357.5*v;
+ dg = dy - 87.75*u - 182*v;
+ db = dy + 451.9*u;
+ break;
+ }
+
if (dr < 0) dr = 0;
if (dg < 0) dg = 0;
case PaintMode_Chroma:
dy = 200; // Default Y value. Lower = darker.
- // Calculate the RGB values from YUV
- dr = dy + 290.8*v;
- dg = dy - 100.6*u - 148*v;
- db = dy + 517.2*u;
+ // Calculate the RGB values from YUV/YPbPr
+ switch (colorSpace) {
+ case VectorscopeGenerator::ColorSpace_YUV:
+ dr = dy + 290.8*v;
+ dg = dy - 100.6*u - 148*v;
+ db = dy + 517.2*u;
+ break;
+ case VectorscopeGenerator::ColorSpace_YPbPr:
+ default:
+ dr = dy + 357.5*v;
+ dg = dy - 87.75*u - 182*v;
+ db = dy + 451.9*u;
+ break;
+ }
// Scale the RGB values back to max 255
dmax = dr;
}
return scope;
}
+
+#include "vectorscopegenerator.moc"
projects / kdenlive / blobdiff