\subsection{Videoscope}%
\label{sub:videoscope}
-Videoscope summarizes intensity and color on a calibrated display. The Videoscope can be used in conjunction with other \CGG{} plugins such as \textit{Color 3 Way}, \textit{YUV}, \textit{Brightness}, \textit{Color Balance} or \textit{Histogram} to accurately correct video for contrast, clarity, conformance (to normalize various videos shot under different light settings), or for cinematic purposes. The human eye is not specialized to match precise level of light and color, but Videoscope is. Videoscope contains three displays: the waveform scope and the vectorscope, plus the histograms (figure~\ref{fig:videoscope01}).
+Videoscope summarizes intensity and color on a calibrated display. The Videoscope can be used in conjunction with other \CGG{} plugins such as \textit{Color 3 Way}, \textit{YUV}, \textit{Brightness}, \textit{Color Balance} or \textit{Histogram} to accurately correct video for contrast, clarity, conformance (to normalize various videos shot under different light settings), or for cinematic purposes. The human eye is not specialized to match precise level of light and color, but Videoscope is. Videoscope contains three displays: the waveform scope and the vectorscope, plus the histograms (figure~\ref{fig:videoscope01}). Instead of applying the plugin to the tracks/edits we want to examine, we can use the Videoscope button in the Composer and Viewer windows. The Videoscope menu window has many options. From the pulldown menu (\textit{Scopes}) we can choose between two histograms (Histogram and Histogram RGB); three waveforms (Waveform, Waveform RGB and Waveform Ply) and two vectorscopes (Vectorscope and VectorWheel). The \textit{Smooth} checkbox serves to make the graph more homogeneous while the \textit{sliders} allow for varying the 'solidity' of the dots shown. You can get to the subpixel
+level for precision.
\begin{figure}[hbtp]
\centering
- \includegraphics[width=0.8\linewidth]{videoscope01.png}
+ \includegraphics[width=1.0\linewidth]{videoscope01.png}
\caption{GUI of the Videoscope. You see Histogram, RGB Parade and Vectorscope}
\label{fig:videoscope01}
\end{figure}
-\subsubsection*{Waveform/RGB Parade}%
-\label{ssub:waveform_rgb_parade}
+\subsubsection*{Waveform/RGB Parade/Waveform Ply}%
+\label{ssub:waveform_rgb_parade_ply}
-The \textit{Waveform Scope} displays image intensity (luminance) versus image $X$ position. The \textit{RGB Parade Scope} displays image RGB intensity versus image $X$ position (one graph per channel). The Waveform Scope appears on the left side or in the middle of the Videoscope window. The display is calibrated vertically from $0\%$ intensity (black) at the bottom up to $100\%$ intensity (white) at the top. Each column of pixels in the image corresponds to one column of pixels in the Waveform Scope (figure~\ref{fig:videoscope02}). Note that the height of the values of a waveform/RGB Parade corresponds exactly to the values on the $x\, axis$ in the \textit{histogram}. A vertical/horizontal correspondence is therefore obtained.
+The \textit{Waveform Scope} displays image intensity (luminance) versus image $X$ position. The \textit{Waveform RGB} (or RGB Parade) displays image RGB intensity versus image $X$ position (one graph per channel). The \textit{Waveform Ply} shows the three channels in a single graph. The Waveform Scope appears on the left side or in the middle of the Videoscope window. The display is calibrated vertically from $0\%$ intensity (black) at the bottom up to $100\%$ intensity (white) at the top. Each column of pixels in the image corresponds to one column of pixels in the Waveform Scope (figure~\ref{fig:videoscope02}). Note that the height of the values of a waveform/RGB Parade corresponds exactly to the values on the $x\, axis$ in the \textit{histogram}. A vertical/horizontal correspondence is therefore obtained.
\begin{figure}[hbtp]
\centering
- \includegraphics[width=0.9\linewidth]{videoscope02.png}
+ \includegraphics[width=1.0\linewidth]{videoscope02.png}
\caption{Colortest 75\% with RGB Parade (left) and Waveform (right)}
\label{fig:videoscope02}
\end{figure}
On the left is shown RGB Parade: instead of the color shadows as in figure~\ref{fig:videoscope01}, we have lines representing the color bar test at $75\%$. They are pure colors, so all pixels have the same value. In fact, they are all at the level of $75\%$ except for the $100\%$ white band and the $0\%$ black band. In the waveform on the right, we have the same behavior with regard to luminance: the white band is $100\%$; the black band is $0\%$ and all the others $75\%$.
-The Waveform scope helps correct image light levels for contrast range or for conforming light levels on various scenes originally shot on different light settings (figure~\ref{fig:videoscope03}).
+The Waveform scope helps correct image light levels for contrast range or for conforming light levels on various scenes originally shot on different light settings (figure~\ref{fig:videoscope03}). The same can be done with RGB Parade or the convenient overlapping representation (Waveform Ply).
\begin{figure}[hbtp]
\centering
- \includegraphics[width=0.7\linewidth]{videoscope03.png}
- \caption{Example of waveform}
+ \includegraphics[width=1.0\linewidth]{videoscope03.png}
+ \caption{Examples of waveform, waveform RGB and waveform Ply}
\label{fig:videoscope03}
\end{figure}
\begin{enumerate}
\item Add the \textit{Brightness/Contrast}, \textit{Histogram}, \textit{Color 3 Way} or another video adjustment effect on your track/edit.
- \item Add the Videoscope effect on the track below. Make sure that it is placed below so it can see the adjustment effect's results. If it is not, right-click and move it down.
+ \item Add the Videoscope effect on the track below. Make sure that it is placed below so it can see the adjustment effect's results. If it is not, right-click and move it down. Or do not use the plugin but activate the Videoscope button in the Compositor window.
\item Show both the effect and Videoscope.
\item Adjust the contrast while observing the waveform to match the desired light level.
- \item Precise adjustments can be made by measuring the values on the waveform with the crosshair (by click with LMB, and reading numeric values on top left of the window) and reporting these numbers in the effects window (\textit{Histogram Bézier}, for example).
+ \item Precise adjustments can be made by measuring the values on the waveform with the crosshair (by clicking LMB, and reading numeric values on top left of the window) and reporting these numbers in the effects window (\textit{Histogram Bézier}, for example).
\end{enumerate}
-For instance, if you are looking for maximum contrast range, adjust the \textit{Brightness/Contrast} levels to align the darkest point on the scope with the $0\%$ level and the brightest portion with $100\%$. Anything above $100\%$ is over saturated. Limits which may be highlighted with checkbox controls.
+For example, if you are looking for maximum contrast range, adjust the \textit{Brightness/Contrast} levels to align the darkest point on the scope with the $0\%$ level and the brightest portion with $100\%$. Anything above $100\%$ is over saturated. Limits may be highlighted with checkbox controls.
\subsubsection*{HDTV or sRGB (ITU-R BT.709)}%
\label{ssub:hdtv_srgb_bt709}
\subsubsection*{Vectorscope}%
\label{ssub:Vectorscope}
-The Vectorscope displays \textit{hue} (angle on the color wheel) and \textit{saturation} (radius). Each pixel in the source image is drawn as a point on the color wheel. The distance from the center is the color saturation. Gray values are close to the center, and high saturation values are near the perimeter ($100\%$). In the center there is pure white ($0\%$). By clicking with the mouse on the color wheel appear radius and circle whose values of hue and saturation are shown at the top left of the window, similar to the values of $X$ and luminance of the Waveform and RGB Parade (figure~\ref{fig:videoscope04}).
+The Vectorscope displays \textit{hue} (angle on the color wheel) and \textit{saturation} (radius). Each pixel in the source image is drawn as a point on the color wheel. The distance from the center is the color saturation. Gray values are close to the center, and high saturation values are near the perimeter ($100\%$). In the center there is pure white ($0\%$). By clicking with the mouse on the color wheel a radius and circle
+will appear whose values of hue and saturation are shown at the top left of the window, similar to the values of $X$ and luminance of the Waveform and RGB Parade (figure~\ref{fig:videoscope05}).
-Vectorscope is used as monitor with other plugins to correct color, adjust image tint, and apply other effects for cinematic effects, image correction, or to conform images to look the same. For example, skin tones are found along an axis (\textit{+ I-line}) between yellow and red, and between $0$ and $50\%$ saturation values. The blue of the sky is more or less along the opposite axis to that of the skin (\textit{- I-line}), with a much wider saturation range.
+\begin{figure}[hbtp]
+ \centering
+ \includegraphics[width=0.9\linewidth]{videoscope05.png}
+ \caption{Vectorscope (with I-Line) and VectorWheel (with IQ-Hue-Tics reticule)}
+ \label{fig:videoscope05}
+\end{figure}
+
+Note that when you choose \textit{VectorWheel} from \textit{Scopes} pulldown, the \textit{Overlay} pulldown
+appears where you can choose between different grids. In addition, any number of user-supplied grid patterns
+can be added in the form of a square image of type png. The user can design and maintain individual grid
+overlays for various purposes. The user would keep their overlays in a safe spot on their disk and make
+a copy of them in the \{cinelerra\_pathname\}/bin/plugins/scopes every time a new version of \CGG{} is installed.
+
+Generally the Vectorscope has the following uses:
+
+\begin{enumerate}
+ \item Compare saturation levels (radius) between Edits.
+ \item Compare the hues (angle) between Edits.
+ \item Compare skin tones, sky and vegetation.
+ \item Display the color balance or color cast.
+ \item Check the legal limits of the video signal.
+\end{enumerate}
+
+ For example, skin tones are found along an axis (\textit{+ I-line}) between yellow and red, and between $0$ and $50\%$ saturation values. The blue of the sky is more or less along the opposite axis to that of the skin (\textit{- I-line}), with a much wider saturation range.
\begin{figure}[hbtp]
\centering
projects / goodguy / cin-manual-latex.git / blobdiff