### 4.8. 選択範囲エディター

選択範囲エディター コマンドは「選択範囲エディター」ダイアログを開きます。 このダイアログは現在操作中の画像上にある選択範囲を図示し、 選択範囲を操作するさまざまなコマンドを容易に呼び出せるしくみが具わっています。 これは直に選択範囲を編集することを想定したつくりではありませんが、 選択操作のコマンドがアイコンボタン化して一堂に会しているのでメニューを辿るよりも手軽にコマンドを呼び出せますから、 選択範囲を扱う作業では重宝するかと思います。 また「選択範囲エディター」ダイアログには「選択範囲をパスに」する変換コマンドに関する高度なオプションもあります。

#### 4.8.1. コマンドの呼び出し方

You can access this command from the main menu through Select → Selection Editor.

#### 4.8.2. 「選択範囲エディター」ダイアログのご説明

図16.19 「選択範囲エディター」ダイアログ

各種ボタン

  「選択範囲エディター」ダイアログには選択操作コマンドを手軽に呼び出せるアイコンボタンが並んでいます。

  - The Select All button.

  - The Select None button.

  - The Select Invert button.

  - The Save to Channel button.

  - The To Path button. If you hold the Shift key while clicking on this button, the Advanced Settings dialog is displayed. Please see the next section for details about these options.

  - The Stroke Selection button.

表示枠

  表示枠内では画像の選択された領域が白く、 選択されていない領域が黒く表示され、 部分選択の領域は灰色濃淡で描かれます。 枠内をクリックすると 色域を選択 ツールで画像をクリックした場合と同じ結果になります。 下図の例をご覧ください。

図16.20 「選択範囲エディター」表示枠をクリックしたときの例

Selection Editor window after clicking.

Image with the resulting selection applied.

#### 4.8.3. The 「Selection to Path Advanced Settings」 dialog

図16.21 「選択領域からパスの詳細設定」ダイアログのウィンドウ

「選択領域からパスの詳細設定」ダイアログは Shift キーを押しながら アイコンボタンをクリックすると現れます。 このダイアログにはスライダーつきの数値入力スピンボックスからなるオプションが 20 個とチェックボックスがひとつあります。 いずれも主に卓越したユーザー向けの内容です。 [ウィンドウの表示がほとんど英語ですが、 これは翻訳スタッフがさぼっているわけではなく、 プログラムのソース自体が翻訳を許さない構造になっているためです。 それだけ開発者寄りの高度な内容であるともいえます。: 訳者注]

Align Threshold

  If two endpoints are closer than this value, they are made to be equal.

Corner Always Threshold

  If the angle defined by a point and its predecessors and successors is smaller than this, it is a corner, even if it is within Corner Surround pixels of a point with a smaller angle.

Corner Surround

  Number of points to consider when determining if a point is a corner or not.

Corner Threshold

  If a point, its predecessors, and its successors define an angle smaller than this, it is a corner.

Error Threshold

  Amount of error at which a fitted spline[8] is unacceptable. If any pixel is further away than this from the fitted curve, the algorithm tries again.

Filter Alternative Surround

  A second number of adjacent points to consider when filtering.

Filter Epsilon

  If the angles between the vectors produced by Filter Surround and Filter Alternative Surround points differ by more than this, use the one from Filter Alternative Surround.

Filter Iteration Count

  The number of times to smooth the original data points. Increasing this number dramatically, to 50 or so, can produce vastly better results. But if any points that 「should」 be corners aren't found, the curve goes wild around that point.

Filter Percent

  To produce the new point, use the old point plus this times the neighbors.

Filter Secondary Surround

  Number of adjacent points to consider if Filter Surround points defines a straight line.

Filter Surround

  Number of adjacent points to consider when filtering.

Keep Knees

  This check box says whether or not to remove 「knee」 points after finding the outline.

Line Reversion Threshold

  If a spline is closer to a straight line than this value, it remains a straight line, even if it would otherwise be changed back to a curve. This is weighted by the square of the curve length, to make shorter curves more likely to be reverted.

Line Threshold

  How many pixels (on the average) a spline can diverge from the line determined by its endpoints before it is changed to a straight line.

Reparametrize Improvement

  If reparameterization doesn't improve the fit by this much percent, the algorithm stops doing it.

Reparametrize Threshold

  Amount of error at which it is pointless to reparameterize. This happens, for example, when the algorithm is trying to fit the outline of the outside of an 「O」 with a single spline. The initial fit is not good enough for the Newton-Raphson iteration to improve it. It may be that it would be better to detect the cases where the algorithm didn't find any corners.

Subdivide Search

  Percentage of the curve away from the worst point to look for a better place to subdivide.

Subdivide Surround

  Number of points to consider when deciding whether a given point is a better place to subdivide.

Subdivide Threshold

  How many pixels a point can diverge from a straight line and still be considered a better place to subdivide.

Tangent Surround

  Number of points to look at on either side of a point when computing the approximation to the tangent at that point.

[8] 「Spline」 is a mathematical term for a function which defines a curve by using a series of control points, such as a Bézier curve.

See Wikipedia for more information.

4.7. Selection From Paths |  | 4.9. 境界をぼかす...

Report a bug in GIMP Report a documentation error