> For the complete documentation index, see [llms.txt](https://overleaf-pro.ayaka.space/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://overleaf-pro.ayaka.space/latex/zh-tw/wen-yu-da/35-how-do-i-specify-the-size-of-an-image-in-latex.md).

# 我該如何在 LaTeX 中指定圖片大小？

要在 Overleaf 文件中插入圖形，你首先必須 [將它上傳到你的專案](/latex/zh-tw/zhi-shi-ku/088-including-images-on-overleaf.md)。假設你已載入了 `graphicx` 套件到你的文件前言：

```latex
\usepackage{graphicx}
```

你可以使用 `scale=...` 選項來指定影像的（排版後）大小： `\includegraphics` 指令：

```latex
\includegraphics[width=0.5\textwidth]{my-uploaded-figure.png}
```

## 範例

* **注意**：以下範例使用了一個圖形檔案（`example-image.pdf`）由 `mwe` 套件提供。這些圖形檔案由 TeX Live 發行，因此儲存在 Overleaf 的伺服器上，可作為圖片預留位置使用，例如下方的範例。

```latex
\documentclass{article}
\usepackage{graphicx}
\begin{document}
影像的原始大小：

\vspace{3pt}
\includegraphics{example-image.pdf}

\vspace{12pt}
影像縮放至 50\%：

\vspace{3pt}
\includegraphics[scale=0.5]{example-image.pdf}

\vspace{12pt}
影像縮放至 25\%：

\vspace{3pt}
\includegraphics[scale=0.25]{example-image.pdf}
\end{document}
```

[在 Overleaf 中開啟這個範例](https://www.overleaf.com/docs?engine=pdflatex\&snip_name=How+to+change+the+size+of+an+image\&snip=%5Cdocumentclass%7Barticle%7D%0A%5Cusepackage%7Bgraphicx%7D%0A%5Cbegin%7Bdocument%7D%0ANatural+size+of+the+image%3A%0A%0A%5Cvspace%7B3pt%7D%0A%5Cincludegraphics%7Bexample-image.pdf%7D%0A%0A%5Cvspace%7B12pt%7D%0AImage+scaled+to+50%5C%25%3A%0A%0A%5Cvspace%7B3pt%7D%0A%5Cincludegraphics%5Bscale%3D0.5%5D%7Bexample-image.pdf%7D%0A%0A%5Cvspace%7B12pt%7D%0AImage+scaled+to+25%5C%25%3A%0A%0A%5Cvspace%7B3pt%7D%0A%5Cincludegraphics%5Bscale%3D0.25%5D%7Bexample-image.pdf%7D%0A%5Cend%7Bdocument%7D)

此範例會產生以下輸出：

![如何在 LaTeX 中變更影像大小](/files/c5826826aa770a271d221c7f126e0ce54f60217d)

我們的預設論文範本中也有此範例——你可以試著透過 [建立一篇新論文](https://www.overleaf.com/docs?template=paper) 來看看影像 `frog.jpg` 如何透過寫下以下內容將其縮放為文字寬度的一部分：

```latex
\includegraphics[width=0.3\textwidth]{frog.jpg}
```


---

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