Gimp - 2.4 Guía Del Usuario
GNU Image Manipulation Program
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Undoing can itself be undone. After having undone an action, you can redo it by choosing Edit → Redo from the image menu,
or use the keyboard shortcut, Ctrl-Y. It is often helpful to judge the effect of an action by repeatedly undoing and redoing it. This
is usually very quick, and does not consume any extra resources or alter the undo history, so there is never any harm in it.
or use the keyboard shortcut, Ctrl-Y. It is often helpful to judge the effect of an action by repeatedly undoing and redoing it. This
is usually very quick, and does not consume any extra resources or alter the undo history, so there is never any harm in it.
Caution
If you undo one or more actions and then operate on the image in any way except by using Undo or Redo, it will no
longer be possible to redo those actions: they are lost forever. The solution to this, if it creates a problem for you, is to
duplicate the image and then operate on the copy. ( Not the original, because the undo/redo history is not copied when
you duplicate an image.)
If you undo one or more actions and then operate on the image in any way except by using Undo or Redo, it will no
longer be possible to redo those actions: they are lost forever. The solution to this, if it creates a problem for you, is to
duplicate the image and then operate on the copy. ( Not the original, because the undo/redo history is not copied when
you duplicate an image.)
If you often find yourself undoing and redoing many steps at a time, it may be more convenient to work with the
, a dockable dialog that shows you a small sketch of each point in the Undo History, allowing you to go back or forward to
that point by clicking.
Undo is performed on an image-specific basis: the "Undo History" is one of the components of an image. GIMP allocates a
certain amount of memory to each image for this purpose. You can customize your Preferences to increase or decrease the
amount, using the
certain amount of memory to each image for this purpose. You can customize your Preferences to increase or decrease the
amount, using the
page of the Preferences dialog. There are two important variables: the minimal number of undo
levels
, which GIMP will maintain regardless of how much memory they consume, and the maximum undo memory, beyond
which GIMP will begin to delete the oldest items from the Undo History.
Note
Even though the Undo History is a component of an image, it is not saved when you save the image using GIMP’s
native XCF format, which preserves every other image property. When the image is reopened, it will have an empty
Undo History.
Even though the Undo History is a component of an image, it is not saved when you save the image using GIMP’s
native XCF format, which preserves every other image property. When the image is reopened, it will have an empty
Undo History.
The implementation of Undo by GIMP is rather sophisticated. Many operations require very little Undo memory (e.g., changing
visibility of a layer), so you can perform long sequences of them before they drop out of the Undo History. Some operations
(changing layer visibility is again an example) are compressed, so that doing them several times in a row produces only a single
point in the Undo History. However, there are other operations that may consume a lot of undo memory. Most filters are examples
of this: because they are implemented by plug-ins, the GIMP core has no really efficient way of knowing what they have changed,
so it has no way to implement Undo except by memorizing the entire contents of the affected layer before and after the operation.
You might only be able to perform a few such operations before they drop out of the Undo History.
visibility of a layer), so you can perform long sequences of them before they drop out of the Undo History. Some operations
(changing layer visibility is again an example) are compressed, so that doing them several times in a row produces only a single
point in the Undo History. However, there are other operations that may consume a lot of undo memory. Most filters are examples
of this: because they are implemented by plug-ins, the GIMP core has no really efficient way of knowing what they have changed,
so it has no way to implement Undo except by memorizing the entire contents of the affected layer before and after the operation.
You might only be able to perform a few such operations before they drop out of the Undo History.
3.3.1
Things That Cannot be Undone
Most actions that alter an image can be undone. Actions that do not alter the image generally cannot be. This includes operations
such as saving the image to a file, duplicating the image, copying part of the image to the clipboard, etc. It also includes most
actions that affect the image display without altering the underlying image data. The most important example is zooming. There
are, however, exceptions: toggling QuickMask on or off can be undone, even though it does not alter the image data.
such as saving the image to a file, duplicating the image, copying part of the image to the clipboard, etc. It also includes most
actions that affect the image display without altering the underlying image data. The most important example is zooming. There
are, however, exceptions: toggling QuickMask on or off can be undone, even though it does not alter the image data.
There are a few important actions that do alter an image but cannot be undone:
Closing the image The Undo History is a component of the image, so when the image is closed and all of its resources are freed,
the Undo History goes along. Because of this, unless the image has not been modified since the last time it was saved,
GIMP always asks you to confirm that you really want to close it. (You can disable this in the
GIMP always asks you to confirm that you really want to close it. (You can disable this in the
page of the
Preferences dialog; if you do, you are assuming responsibility for thinking about what you are doing.)
Reverting the image ‘Reverting’ means reloading the image from file. GIMP actually implements this by closing the image
and creating a new image, so the Undo History is lost as a consequence. Because of this, if the image is unclean, GIMP
always asks you to confirm that you really want to revert the image.
always asks you to confirm that you really want to revert the image.
‘Pieces’ of actions Some tools require you to perform a complex series of manipulations before they take effect, but only allow
you to undo the whole thing rather than the individual elements. For example, the Intelligent Scissors require you to create