Welcome to the Corel tutorial on using PaintShop Pro's Background Eraser tool.
This tool does exactly what it sounds like it does, in that it can single out a
certain area of your image, allowing you to delete it and either replace it with
something new or place it onto a web page and allow the background show
through. In either case PaintShop Pro does it a whole lot easier than using a
generic Eraser tool. You use the Background Eraser tool to erase
pixels selectively. For example, in a photo of some mountains you can erase
and replace the sky or you can isolate an object from the surrounding image
area and combine it with something else. Kind of similar to making a selection. As
usual, go to the tutorial page and download the written tutorial and sample
images if you'd like to follow along. The written part also has instructions to
complete this tutorial at any time on your own. So you can probably guess the
difference between this tool and the regular Eraser, but let's quickly review
the Eraser anyway. The Eraser is an all-or-nothing tool: it doesn't
distinguish between colors like the Background Eraser tool does. On the other
hand, it does have a feature called Smart Edge, which acts like a basic background
eraser in that it automatically finds the edges of irregularly-shaped areas when
you click along the edges. This can provide a shortcut if desired. This
feature is also available when using the Painting tools and some of the Selection tools.
Let's go to the Background Eraser. We'll also review and choose some
of this tool's options in its tool bar as we go along. Full explanations of the
tool options will be at the end. I'll use the same image of a pier, a lighthouse
and the ocean and some hills beyond. I've selected the Background Eraser which is
in the same flyout as the regular Eraser tool. The technique to start and using
this is telling the tool which part to erase and which part to retain. Your
cursor will look like an inverted eraser surrounded by a circle. The center point
will determine the sample to work with or the range of colors to erase. The
circle represents the area that will be erased but the circle will not erase
colors outside the sampled color range. This will quickly become clear as I
start removing the background. I'll set the eraser size to about 200. I can do
this two ways: I can either set it in the tool options bar or I can hold the on
the Alt key and drag my mouse to interactively change the eraser size.
Good to note though, is that large sizes may slow down their process. I've set
opacity to 100 to erase everything on the first pass, even though you may still
have to repeat parts of an area again. Larger brush sizes and your erasing speed
may cause this. I have also set it to Contiguous under the Limits drop down.
This will only erase colors that are connected to the main erasing area. This
option will help in some areas but not others. I'll show you what I mean as we
go along and the ways around that.
As you can see, I'm only erasing the sky because that's where the center point is
located. I'm leaving the ocean and the lighthouse alone because only the outer
circle reaches into that area but not the center point. The tool sees the edge,
sees the color differences and knows to ignore them because the colors are so
different, which is set by the tolerance level. Here's the end result. You'll
notice that the erased background indicates as transparent as noted by the
checkerboard pattern. Once you're done with this process you can save it as a
PNG file, drop it on a web page and the background that's already on that page
will show in this transparent area. OK let's step this up a bit, add some
excitement to this process and erase the background right into another background!
I'll return back to the original image. I'll also open a sunset image. Switch
back to the pier image, right-click and choose Copy. Switch back to the sunset
page, right-click and choose Paste > Paste as New Layer. The sunset is now
designated as my background layer and the pier image is now set to be on top
of it. Using the Background Eraser tool with the same settings, I can erase the
sky and directly replace it with the sunset because it's behind it. So as you
can guess, I'm making parts of the top image transparent so the one behind it
shows through.
Notice the inside of the hanging sign has not been erased, same thing with the
very top of the lighthouse. These are going to be really hard to get to unless
I do this: I'll back up a step or two and then choose the Discontiguous option
under the Limits drop down. This option will erase colors that fall into the
eraser's limits but are disconnected from the main area.
Another nice shortcut is to hold down the Shift key, click on one end of where
you want to erase then while still holding Shift, click on the other end
like this. I'll use this technique to finish up the rest of my background
erasing.
Another important shortcut is that right-clicking while using the
background eraser will bring back whatever I've erased. Now I'll just brush
over a few areas again to make them complete and we'll be done.
Now that you've seen how easy it is to erase a background, there are several
other option settings you can use. For more details on these, refer to the
downloadable PaintShop Pro PDF user guide accessed under your Help menu but
here are a few of them. Opacity means a lower setting will erase pixels to
partial transparency. Tolerance determines how closely the selected
pixels match the sample pixel or where you first clicked.
Sharpness specifies the softness of the erased edge. A softer brush creates
anti-aliased edges. Sampling specifies the basis on which pixels are erased.
This control has the following options: a) "Once" samples the point at which you
first click and then erases all matching pixels for the duration of the stroke;
b) "Continuous" samples continuously and erases all matching pixels it encounters
including foreground colors if the sampled pixel falls into the foreground
area; c) "BackSwatch" erases all pixels that match the current background color on
your Materials palette; d) "Foreswatch" on the other hand erases all the pixels that
matched the current foreground color in your Materials palette. Limits specifies
whether erased pixels are adjacent to each other with the following options:
a) "Discontiguous" erases all pixels in the tool's path that match the sampled pixels,
even if they are non-adjacent. We used this on the lighthouse and the sign.
b) "Contiguous" erases only contiguous pixels that match sampled pixels. This setting
would have skipped to areas inside the lighthouse and the sign. Auto tolerance
determines which is erased based on the color range from the first color you
click on. You can uncheck this manually and set the tolerance level yourself. Use
All Layers samples data from all layers that are merged together but only pixels
in the current layer are actually erased. To sample data from the current layer
only, just uncheck this box. Ignore Lightness ignores sharp differences in
color, lightness and saturation. You can mark this
box when the colors in the object that you want to isolate are strongly
saturated and the background is unsaturated or vice versa. If you're
watching this video on YouTube you'll find a link in the description below
that will take you to our tutorial page on the Discovery Center. Here you can
download a written copy of this tutorial to follow along and find other helpful
tutorials for working with transparencies in PaintShop Pro.