This article will explain how to work with images when performing tasks such as changing the size or making a transparent background.
We will use an online photo edition program that does not require installation, download nor registration. You can access this free service at www.pixlr.com.
Starting with PIXLR:
Start by accessing the site mentioned above. And click on the highlighted link in red(Editor):
We will be asked if we want to create an image from scratch or work with an existing image:
Working from existing image:
For this example we will work from an existing image. The purpose of this exercise is to:
- Resize original to 512x512 pixels
- Make outline curved instead of rectangle
- Make background transparent
We will work with the image on the left and transform it into the one on the right:
As we said, we will work from an existing file so we will click on "open image from computer(you can copy it first from this article)":
Now we select the Crop tool and define its parameters as shown inside the red rectangle.(output size= 512 x 512). Just click and drag to define the selected area as shown on the following image:
You can click and drag around the selection until you are happy with it. Once you are happy with the selection, just click inside the selected area and the image will be cropped and resized to 512x512 pixels: 
Now we will define the border so it is more rounded and not squared. Select the Selection tool and put its value to 35:
Click on the dot marked as 1 and drag without releasing the button to the dot marked as 2 as shown in the following image:
Place the mouse inside the selected area and click the right button on the mouse. Now click on "Invert selection":
Place the mouse over the lock icon on your image layer box and double click. The lock should become a selected checkbox:
Now the background layer has been unblocked, allowing us to erase the default white background if wanted. So let's change to the Erase tool and start erasing the selected area:
The result should look similar to the following image. If so, click file and save:
If you do not save as PNG format, the transparent background will look white again: