You will need
  • image editor, picture
Instruction
1
To make preview pictures, you need to upload a large image file in a graphics editor such as Adobe Photoshop or similar. Then reduce the size of pictures in pixels. Usually used for preview pictures resolution about 200x200 pixels, but for your purposes, perhaps a different size.
2
Save a smaller version of the picture in a separate file. In some editors you can select the compression ratio. If you send a picture to the Internet, you can apply a little more compression to the image load faster for those who view your text.
3
For preview do not have to reduce the whole image, some prefer to cut a small piece and as a preview to use it. It depends on your taste preferences and goals of the text.
4
Then upload both images to the file hosting. You need to get the direct address for both images. Code to embed the images:
<a href="direct link to big picture"><img src="direct link to small picture preview"></a>