getframe (MATLAB Functions)

Get movie frame

Syntax

F = getframe
F = getframe(h)
F = getframe(h,rect)

Description

getframe returns a movie frame. The frame is a snapshot (pixmap) of the current axes or figure.

F = getframe gets a frame from the current axes.

F = getframe(h) gets a frame from the figure or axes identified by the handle h.

F = getframe(h,rect) specifies a rectangular area from which to copy the pixmap. rect is relative to the lower left corner of the figure or axes h, in pixel units. rect is a four-element vector in the form [left bottom width height], where width and height define the dimensions of the rectangle.

F = getframe(...) returns a movie frame, which is a structure having two fields:

cdata -- The image data stored as a matrix of uint8 values. The dimensions of F.cdata are height-by-width-by-3.
colormap -- The colormap stored as an n-by-3 matrix of doubles. F.colormap is empty on true color systems.

To capture an image, use this approach:

F = getframe(gcf);
image(F.cdata)
colormap(F.colormap)

Remarks

Usually, getframe is used in a for loop to assemble an array of movie frames for playback using movie. For example,

for j = 1:n
    plotting commands
    F(j) = getframe;
end
movie(F)

Capture Regions

Note that F = getframe; returns the contents of the current axes, exclusive of the axis labels, title, or tick labels. F = getframe(gcf); captures the entire interior of the current figure window. To capture the figure window menu, use the form F = getframe(h,rect) with a rectangle sized to include the menu.

Examples

Make the peaks function vibrate.

Z = peaks; surf(Z)
axis tight
set(gca,'nextplot','replacechildren');
for j = 1:20
    surf(sin(2*pi*j/20)*Z,Z)
    F(j) = getframe;
end
movie(F,20) % Play the movie twenty times

See Also

frame2im, image, im2frame, movie

Bit-Mapped Images for related functions

getfield get (memmapfile)