Below is my latex:
\usepackage[ruled,longend]{algorithm2e}
\begin{algorithm}
$I \gets \text{Images of objects' plane}$\newline
$Detector \gets \text{Define detector}$\newline
$Descriptor \gets \text{Define Descriptor}$\newline
\end{algorithm}
But the first line is un aligned
Line-ends within an algorithm environment under algorithm2e require the use of \;, not \newline.
\documentclass{article}
\usepackage{amsmath}
\usepackage[ruled,longend]{algorithm2e}
\begin{document}
\begin{algorithm}
$I \gets \text{Images of objects' plane}$\;
$\text{Detector} \gets \text{Define detector}$\;
$\text{Descriptor} \gets \text{Define Descriptor}$\;
\end{algorithm}
\end{document}
If you don't like the semicolons printed, then add
\DontPrintSemicolon
somewhere after loading algorithm2e.
\DontPrintSemicolon remove all the semicolons in the text or just in the algorithm section?
\; within the algorithm environment.