help for working with color from Andrea via DeJay

diff --git a/parts/Attributes.tex b/parts/Attributes.tex
index 9f466c3638eae5665d830df04eb675e2851154d7..0dd076927a081b075ef81a55144c0376124c7acb 100644 (file)
--- a/parts/Attributes.tex
+++ b/parts/Attributes.tex
@@ -240,6 +240,7 @@ Generally, best practice is to perform the following sequence of preparations fo
        source: \textit{rec709} $\rightarrow$ monitor: \textit{sRGB} (we get slightly faded colors) \\
        source: \textit{rec709} $\rightarrow$ monitor: \textit{DCI-P3} (we get over-saturated colors)
        \item It would be better to set the project as RGB(A)-FLOAT, allowing system performance, because it collects all available data and does not make rounding errors. If we can't afford it, starting from YUV type media it is better to set the project as YUV(A)8, so as not to have a darker rendering in the timeline. On the contrary, if we start from RGB signals, it is better to use RGB(A)8. If we don't display correctly on the timeline, we'll make adjustments from the wrong base (metamerism) and get false results.
+       \item Having correct color representation in the Compositor can be complicated. You can convert the imput \textit{YUV color range} to a new YUV color range that provides more correct results (i.e. MPEG to JPEG). The \texttt{Colorspace} plugin can be used for this conversion.
        \item Among the rendering options always set the values \\      
        \texttt{color\_trc=...} (gamma correction) \\
        \texttt{color\_primaries=...} (gamut) \\

diff --git a/parts/Stuff.tex b/parts/Stuff.tex
index 2e567ace21f0897feeb12df2be69121b9083bdc3..867e8007227da12ba1409b8756c93eeded7ff7f1 100644 (file)
--- a/parts/Stuff.tex
+++ b/parts/Stuff.tex
@@ -170,9 +170,20 @@ Some general tips (See also \ref{sec:video_attributes} \textit{Color model}):
 \begin{itemize}
        \item If your hardware allows it use RGB-Float (in \texttt{Settings $\rightarrow$ Format}); this format does not lead to transfer errors from one model to another, but it uses more cpu.
        \item Use RGB-8 if the source is RGB and YUV-8 if the source is YUV (most commonly used).
-       \item If you notice alterations in color/brightness representation, try playing with color models in \texttt{Settings $\rightarrow$ Format} and with \textit{YUV color space} and \textit{YUV color range} in \texttt{Settings $\rightarrow$ Preferences $\rightarrow$ Appearance} tab. Another possibility is to check if the display color model conforms to the project color model.
+       \item If you notice alterations in color/brightness representation, try playing with color models in \texttt{Settings $\rightarrow$ Format} and with \textit{YUV color space} and \textit{YUV color range} in \texttt{Settings $\rightarrow$ Preferences $\rightarrow$ Appearance} tab. Another possibility is to check if the display color model conforms to the project color model. A practical case that may arise is as follows\protect\footnote{thanks to DeJay}: YUV source with limited color range (MPEG or TV); \CGG{} set with the color range to extended (JPEG or PC); the colors on the compositor will be flattened. If we set the color range to MPEG the colors will be correct but hard clipping will occur. In this case the best result is presented by setting the color range to JPEG but then doing a conversion of the source to JPEG color range via the \texttt{ColorSpace} plugin. Summary table:
 \end{itemize}
 
+\begin{center}
+       \begin{tabular}{ |c|c|c| } 
+               \hline
+               \textbf{Source} & \textbf{YUV Color Range} & \textbf{Colors} \\ 
+               \hline
+               MPEG & JPEG & Flat colors \\ 
+               MPEG & MPEG & Hard clipping \\
+               MPEG + conversion to JPEG & JPEG & Colors OK \\
+               \hline
+       \end{tabular}
+\end{center}
 
 \section{Automatic "Best Model" Media Load}%
 \label{sec:conform_the_project}