3. 실행 취소하기
| 3장. 윌버와 함께하는 첫 단계 |

## 3. 실행 취소하기

Almost anything you do to an image in GIMP can be undone. You can undo the most recent action by choosing Edit → Undo from the image menu, but this is done so frequently that you really should memorize the keyboard shortcut, Ctrl+Z.

실행 취소 또한 취소할 수 있는데, 이것은 실행 취소를 한 다음에 이미지 메뉴에서 편집 → 재실행 를 선택하거나 단축키 Ctrl+Y 를 누르면 됩니다. 실행 취소와 재실행은 종종 특정 작업의 효과를 확인하기 위해 사용됩니다. 이는 대체로 빠르고, 추가적인 리소스도 필요하지 않고, 실행취소 이력에 어떠한 영향도 주지 않기 때문에 여러번 반복해도 무방합니다.

| 경고
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 test on the copy. ( Do Not test the original, because the undo/redo history is not copied when you duplicate an image.)

한번에 많은 과정을 실행 취소하거나 재실행하는 일을 자주한다면, 실행 취소 이력 대화 상자를 이용하면 편리합니다. 이 대화 상자에는 실행 취소 이력의 각 포인트마다 개략적 미리보기가 있어 단지 클릭만 함으로써 해당 과정으로 실행 취소하거나 재실행할 수 있습니다.

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 Environment 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.

| 참고
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.

GIMP's implementation of Undo 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, such as changing layer visibility, 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 implemented by plug-ins, so the GIMP core has no efficient way of knowing what changed. As such, there is 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.

### 3.1. 실행 취소를 할 수 없는 것들

Most actions that alter an image can be undone. Actions that do not alter the image generally cannot be undone. Examples include 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.

이미지에 변형을 가하지만 취소할 수 없는 작업 목록 :

이미지 닫기

  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 is gone. 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 the image. (You can disable this in the Environment page of the Preferences dialog; if you do, you are assuming responsibility for thinking about what you are doing.)

이미지 원래대로 만들기

  “Reverting” means reloading the image from the 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 asks you to confirm that you really want to revert the image.

동작의 “일부분”

  어떤 도구들은 해당 도구를 사용하기 위해 복잡한 편집과정들을 요구하기도 합니다. 이런 경우 그 각각의 과정들에 대해서는 실행 취소를 할 수 없고, 오직 전체 과정에 대한 실행 취소만 할 수 있습니다. 예를 들어 "똑똑한 가위" 도구는 이미지 위에 여러 지점을 찍어 폐쇄된 경로를 만들고, 그 내부를 클릭해서 선택을 만듭니다. 이 상태에서 실행 취소를 하면 바로 직전에 한 클릭이 아닌 "똑똑한 가위" 를 시작한 처음 지점으로 돌아갑니다. 다른 예를 들자면, 텍스트 도구를 사용할 경우, 각각의 문자나 글씨체 변환 등의 작업은 취소할 수 없고, 실행 취소를 하면 텍스트 레이어가 사라지며 새로운 텍스트 레이어가 나타납니다.

Filters, and other actions performed by plugins or scripts, can be undone just like actions implemented by the GIMP core, but this requires them to make correct use of GIMP's Undo functions. If the code is not correct, a plugin can potentially corrupt the Undo History, so that not only the plugin but also previous actions can no longer properly be undone. The plugins and scripts distributed with GIMP are all believed to be set up correctly, but obviously no guarantees can be given for plugins you obtain from other sources. Also, even if the code is correct, canceling a plugin while it is running may corrupt the Undo History, so it is best to avoid this unless you have accidentally done something whose consequences are going to be very harmful.

2.3. 대화 상자와 도킹 |  | 4. 간단한 김프 사용법