如何在Mac上使用终端调整图像大小？

Question

我需要一个简单和免费的方式来调整图像大小和做批处理，如果必要的话。自由图像处理软件的使用比它应该使用的要复杂得多。

Answer 1

正如LifeHacker所指出的，下面的命令将非常容易地做到这一点：

sips -Z 640 *.jpg

引用他们的解释：

"sips是正在使用的命令，-Z告诉它保持图像的纵横比。"640“是要使用的最大高度和宽度，"*.jpg”指示计算机缩小以.jpg结尾的每幅图像的大小。它非常简单，而且缩小图像的速度非常快。如果您想要保留它们更大的大小，请务必先复制它们。“

来源：http://lifehacker.com/5962420/batch-resize-images-quickly-in-the-os-x-terminal

Answer 2

影象帮助：

$ convert foo.jpg -resize 50% bar.jpg

它可以做更多的事情，包括格式之间的转换、应用效果、裁剪、着色等等。

Answer 3

下面是使用sips递归调整给定文件夹(及其子文件夹)中所有图像大小的脚本，并将调整大小的图像放在与图像相同的树级上：https://gist.github.com/lopespm/893f323a04fcc59466d7。

#!/bin/bash
# This script resizes all the images it finds in a folder (and its subfolders) and resizes them
# The resized image is placed in the /resized folder which will reside in the same directory as the image
#
# Usage: > ./batch_resize.sh

initial_folder="/your/images/folder" # You can use "." to target the folder in which you are running the script for example
resized_folder_name="resized"

all_images=$(find -E $initial_folder -iregex ".*\.(jpg|gif|png|jpeg)")

while read -r image_full_path; do
    filename=$(basename "$image_full_path");
    source_folder=$(dirname "$image_full_path");
    destination_folder=$source_folder"/"$resized_folder_name"/";
    destination_full_path=$destination_folder$filename;

    if [ ! -z "$image_full_path" -a "$image_full_path" != " " ] &&
        # Do not resize images inside a folder that was already resized
        [ "$(basename "$source_folder")" != "$resized_folder_name" ]; then 

        mkdir "$destination_folder";
        sips -Z 700 "$image_full_path" --out "$destination_full_path";

    fi

done <<< "$all_images"