prompter: What is a good, free way to scale a large batch of images down? They are of different sizes with the same aspect ratio. The target size is all going to be the same dimensions.

assistant: There are many programs that can accomplish the task of rescaling a large batch of images. Finding a good one for you depends on the details of your environment. Let's start with getting a little more information. What kind of device are you using? For instance, are you using a Windows PC, an iPhone, a Linux server, or something else?

prompter: PC

assistant: Since you are using a PC, I assume you are running either Windows or Linux. I will provide solutions for both operating systems.

### For Windows:

IrfanView is a lightweight, free image viewer and editor that supports batch processing. Here's how you can use it to batch-resize your images:

1. Download and install IrfanView from the official website: https://www.irfanview.com/
2. Open IrfanView and go to "File" > "Batch Conversion/Rename."
3. In the "Batch Conversion" window, set the "Directory" field to the folder containing your images.
4. Choose a destination folder for the resized images in the "Output directory for result files" field.
5. Select "Batch conversion" and choose the desired output format (e.g., JPEG) from the "Output format" dropdown menu.
6. Check the "Use advanced options" box and click the "Advanced" button.
7. In the "Advanced options" window, check "RESIZE" and choose "Set new size" or "Set new size as a percentage of original."
8. Enter your desired dimensions or percentage and make sure the "Preserve aspect ratio" is checked to maintain the aspect ratio of your images.
9. Click "OK" to close the "Advanced options" window.
10. Back in the "Batch Conversion" window, click the "Start" button to resize your images.

### For Linux:

You can use ImageMagick, a powerful command-line-based image processing tool. To install and use ImageMagick for batch resizing, follow these steps:

1. Install ImageMagick from your package manager. For example, on Ubuntu-based systems, you can run:

```
sudo apt-get update
sudo apt-get install imagemagick
```

2. Open the terminal and navigate to the folder containing your images using the "cd" command.
3. Run the following command to resize all images in the current directory to the desired dimensions (e.g., 800x600 pixels) while maintaining the aspect ratio:

```
mogrify -resize 800x600 *.jpg
```

Replace "800x600" with your desired dimensions and "*.jpg" with the appropriate image file extension.

These tools should help you resize your large batch of images quickly and efficiently.

assistant: One good, free way to scale a large batch of images down is to use the command line tool "ImageMagick". ImageMagick is a free and open-source software suite for displaying, converting, and editing raster image files. To scale a batch of images using ImageMagick, follow these steps:

1. Install ImageMagick on your system. You can download it from the official website or install it using your package manager.

2. Open a terminal or command prompt and navigate to the directory where your images are stored.

3. Run the following command to scale all the images in the current directory to a target size of 800x600 pixels:

    `magick mogrify -resize 800x600! *.jpg`

   This command resizes all the JPEG images in the current directory to a width of 800 pixels and a height of 600 pixels, while maintaining the aspect ratio. The exclamation mark at the end of the size specification tells ImageMagick to ignore the aspect ratio and force the images to the specified size.

4. Wait for the command to finish executing. The original images will be replaced with the scaled versions.

ImageMagick is a powerful tool with many options for resizing and manipulating images. For more information, see the official documentation at https://imagemagick.org/script/command-line-tools.php.

assistant: There are many ways to scale down images in large groups. 
You will may be able to find a free service online that will convert large batches of images, but upload and download times will slow you down. 
I would instead, recommend using a free offline software such as GIMP which works on Windows, Linux and Mac. 

You can download GIMP here:
https://www.gimp.org/downloads/ 

Would you like help installing GIMP on your computer?

prompter: I said BATCH of images, not one image

assistant: My apologies for misunderstanding your question. GIMP can also handle batch image processing. Here's how to use it to scale a large batch of images down:

1. Open GIMP and go to "File" > "Batch Process".
2. Click the "Add Files" button to select the images you want to resize.
3. Choose the output folder where the resized images will be saved.
4. Under "Common" tab, check "Resize" and enter the target size dimensions you want.
4. Click "Export" to start the batch process.
5. GIMP will then process all the selected images and resize them to the target size.

prompter: Thanks for the clarification and the detailed instructions! That sounds like exactly what I need. I'll give it a try and let you know if I have any further questions.

assistant: You can use `mogrify` command line tool from ImageMagick for batch image processing: https://imagemagick.org/

The following command resizes all .jpg images of current directory into same target size 1024x768, and store the new images into subfolder "processed":

    magick mogrify -resize 1024x768! -path processed *.jpg

The following command resizes all .jpg and .png images of current directory into 50% of their original sizes, and store the new images one folder up:

    magick mogrify -resize 50% -path .. *.jpg *.png

Be careful that if you do not specify `-path`, the new images will be saved in current directory, overwriting existing files.

prompter: That worked. Can you put that into a bash script?

assistant: You can use the program ImageMagick for that. ImageMagick is a free and open source program that offers the command line program `convert`. `convert` can apply multiple transformations to an input file, including resizing. By using a shell script, you can apply `convert` to multiple images with one script.