How to reduce the size of the image [duplicate]

Question

Example: I have some pictures with size about 3 MB, and want them to have a size about 1020 KB. I don't know is there some option on Ubuntu or I do that with some editor, so can you help me?

My current way is to cut them, but that is not very useful. :(

Maybe this is not a question for this site, but I don't know where to ask.

Answer 1

What it sounds like is you want to take images that are 3MB in file size and store them as smaller file size on disk using an image editing tool on Ubuntu.

You can use Shotwell which comes with Ubuntu Desktop 18.0.4.

• Take all your original images and put them in a folder.
• Choose File | Import From Folder and navigate to it. Shotwell will bring all the images into its own gallery
• Double click on the image you want to downsize

• Select File | Export and change properties to:

  • Format: JPEG
  • Quality: Choosing a lower quality will reduce the file size but it may not look as good. So you have to experiment. Start off with High (90%).
  • Scaling constraint:
    • If the image is in a portrait (longer height than width) choose Height
    • If the image is in landscape (longer width than height) choose Width

  • Pixel

    • If you chose Height in Scaling constraint, this will resize the height to this many pixels. Type in 1/2 the height. It will keep the width in the same proportion to avoid stretching

    • If you chose Width in Scaling constraint, this will resize the width to this many pixels. Type in 1/2 the width. It will keep the height in the same proportion to avoid stretching.

      Making the pixel width (or height) smaller will reduce file size.

• Save the file with a different name. Use a naming convention to distinguish original from modified.

  Example:

  -  Original is: Hello.jpg
  -  Modified is: Hello-600.jpg (if you changed pixel parameter to 600 pixels).