Very often when formatting your posts some pictures need to be resized. Normaly you would download it, resize it and upload it again. This takes time and there is actually a much better, easy and quick way to do it, inside the Markdown editor.

Every image you post on Steemit gets the following prefix:

https://img1.steemit.com/0x0/

If you would to add the following picture URL

https://i.imgur.com/MCTL4zE.jpg

The editor will add the following prefix:

https://img1.steemit.com/0x0/https://i.imgur.com/MCTL4zE.jpg

Where /0x0/ stands for the size of the image. A value of /0x0/ will render the original size.

Now lets say you have this image which is 600x300 pix

In order to change its size just add the following code with the attributes you want. I would like to have it smaller by a half.
The code would look like this:

https://img1.steemit.com/300x150/https://i.imgur.com/MCTL4zE.jpg

This is the result

You can also specify only the height or width and leave the other attribute empty, and the code will also work. You can have the same result with the following code:

https://img1.steemit.com/300x0/https://i.imgur.com/MCTL4zE.jpg