The Fireworks Fuzzy Edge Quick Knockout Mask
Keep your edges in line

Masking fuzzy or irregular edges is typically a slow, painstaking procedure of hand selection with the Polygon Lasso tool, or if you prefer a vector mask, the Pen tool. Plugins that automate the process (e.g., Extensis Mask Pro, Corel Knock Out) are expensive for one-trick ponies. And shame on Extensis and Corel - they haven't been made available for Fireworks. This article will teach you to quickly mask objects with irregular edges using the new Fireworks MX 2004 Replace Color tool, a simple Alpha masking technique, and some sneaky edgerefining tricks.

I'm going to use a gorgeous flower image (see Image I), photographed by Daniel Reyes of Sydney, Australia, to demonstrate the technique. (If you'd like to download a copy and follow along, go to www.playingwithfire.com/flower.zip.) Unzip the image file, and open it in Fireworks MX 2004.

A Word About Masks
In Fireworks you can apply two kinds of masks: clipping masks and Alpha masks. Clipping masks work like cookie cutters, clipping the underlying objects to the shape of the mask. If you've ever pasted one object inside another in Fireworks, you've used a clipping mask.

Alpha masks affect the visibility of underlying objects. They are made with grayscale gradients that tell Fireworks how much to blend the underlying pixels with the pixels of the background it sits on. If you want to fade one image into another or make part of an image invisible, you use an alpha mask.

Preparing the Alpha (?) Mask
Since the mask we'll create is going to work like a cookie cutter, it could be called a clipping mask. But since our mask will fade part of the image, it will work as an Alpha mask. Instead of concerning ourselves with these technical details, let's just do it.

Step 1

  • Select the image by clicking on it and choose Edit _ Clone.
  • Open the Layers panel and select the lower, flower-image thumbnail.
  • Hide the selected image by clicking on the hide object icon (the eyeball). There is good contrast between the

flower and the background of the image in Daniel's photo. That means it can do most of the work of preparing the Alpha mask by adjusting the contrast.

  • Click on the image to select it.
  • Choose Filters _ Adjust Color _ Brightness/Contrast. The Brightness/Contrast dialog box will open (see Image II).
  • Move the Brightness slider all the way to the left, to the -100 position.
  • Move the Contrast slider all the way to the right, to the 100 position. This reduces the number of colors in the image to four or five, and makes the next step, replacing colors, go very quickly (see Image III).

Step 2
Select the Replace Color tool. Set the properties for the Replace Color tool in the Property inspector, as follows:

Size: 70
Shape: Round
Tolerance: 50
Strength: 200

To set the Change property:

  • Click in the Change fill color box in the Property inspector to open a swatches pop-up.
  • Use the built-in color picker of the swatches pop-up to select the green color adjacent to the upper left flower petals.
To select the color you want to change the green to:
  • Click in the To Fill color box in the Property inspector.
  • Use the built-in color picker to select the black swatch in the swatches popup (see Image IV)
  • Click and drag the Color Replacement brush over the image background to replace all of the green pixels with black

Let's select a new color to change.

  • Click in the Change fill color box to open the swatches pop-up.
  • Use the built-in color picker of the swatches pop-up to select the aqua color near the top right of the image. Leave the remaining settings as they are.
  • Sweep quickly over the image with the Replace Color brush to change all the aqua pixels to black.
We need to remove the white and yellow pixels in the background next. It's necessary to exercise some care when replacing these pixels because there are white and yellow pixels at the edges of the flower that we need to preserve. Enlarging the image will make this a snap.
  • Click in the Set Magnification box at the bottom of the document window. Choose 300% from the pop-up menu (see Image V). Alternatively, select the Zoom tool from the bottom of the Tools panel and click a couple of times in the area you want to work on first.
  • Make the Change color either white or yellow.
  • Reduce the size of the Replace Color brush to 18 or less.
  • Replace the white or yellow pixels in the background with black, being careful not to go over the outside edges of the flower petals.
When you've finished replacing the color you selected, switch the Change color and carefully remove the unwanted pixels of the other color.

There are some scattered blue and pink pixels left in the background. Use the Replace Color tool to change them to black, or paint over them with the Paint Brush tool.

Step 3
In this step we'll prepare the flower portion of the image for our Alpha mask.

  • Click in the Change fill color box on the property inspector to open the swatches pop-up.
  • Use the swatches pop-up color picker to select a white area inside the flower.
  • Click in the To color box in the Property inspector and use the swatches pop-up color picker to select the red color of the flower.
  • Sweep over the flower with the Replace color tool to change the remaining white pixels to red.
  • Replace the white Change color with the yellow from the image.
  • Sweep over the flower with the Replace Color tool to replace all the yellow pixels with red.
  • Replace any pink pixels with red.
  • Replace the black pixels inside the flower with red.
The entire image has quickly been reduced to black and red. Next, we want to change it to black and white.
  • Set the Change color to the red from the image.
  • Replace the To color with white.
  • Set the Tolerance to 100.
  • Brush over the red pixels in the image with the Replace color brush to change them to white (see Image VI).
Our Alpha mask is nearly finished. The last step before masking the image is feathering the edges of the mask.

Step 4
If we use the Alpha mask as it is, the edges of the flower petals might look jagged. To soften them, we'll select the black background and pour a feathered fill into the selections.

  • Click on the Magic Wand tool.
  • Set the Tolerance for the Magic Wand tool to 33 in the Property inspector.
  • Set the Edge property for the Magic Wand to Feather, and the amount of feather to 1 (see Image VII).
  • Press Shift and select the three black sections of background around the flower.
We'll fill the selections with the Paint bucket tool.
  • Click in the Fill Color box on the Tools panel.
  • Select a black swatch to set the fill color to black.

Note: If you see a color in the Stroke Color box in the Tools panel, click on it and change the color property to None.

  • Click on the Paint Bucket tool to select it.
  • Click three or four times in each of the areas you selected with the Magic Wand.
  • Choose Select _ Deselect to turn off the marquees (marching ants).

The edges of the flower shape are now anti-aliased to the black background and our Alpha mask is complete.

Applying the Alpha Mask
Before applying the mask we need to unhide the original image. In the Layers panel, make the hidden image visible again by clicking on its thumbnail. Now for the fun part!

  • Press Shift and select both the Alpha mask thumbnail and the original image thumbnail.
  • Choose Modify _ Mask _ Group as mask (see Image VII).

Shazam!

The black background disappears, instantly converting the flower to an image object floating on a transparent canvas (see Image IX). That is just way too cool. If you'd like to perform this trick again, choose Modify _ Ungroup. Shift + select the two bitmaps again and choose Modify _ Mask _ Group as mask.

The edges of the knocked-out flower may still look a bit rough. In the next section I'll show you how to smooth them by applying some Fireworks Live Effects.

Refining the Edges
The edges shouldn't need much touching up, particularly since you would reduce the dimensions of an image this size before using it on a Web page. If you feel the edges need smoothing all the way around the flower, then with the masked image still selected

  • Click on the Add Effects button [+] on the Property inspector.
  • Choose Shadow & Glow _ Glow.
  • Click in the color box of the Glow dialog and select a medium color from the edges of the flower petals (see Image X). If you're not satisfied with the color you can change it later.
  • Click on the down arrow next to the Glow width text box and use the slider to change the width to 1.
  • Set the Glow softness to 1 by means of its slider, or by simply typing a new number into the text box. If just one side of the image edge needs smoothing, choose the Drop

Shadow Live Effect.

  • Click on the Add Effects button [+] on the Property inspector.
  • Choose Shadow & Glow _ Drop Shadow.
  • Click in the color box of the Drop Shadow dialog and select a medium color from the edges of the flower petals.
  • Adjust the Shadow width to 1.
  • Set the Shadow softness to 1.
  • Click on the down arrow next to the angle text box and use the built-in dial to rotate the shadow to the correct position.

Other live effects you can use to adjust the edges of your extracted image are Inner Glow and Inner Shadow.

Finishing Up
To check the quality of our work, let's add a background. Select the Vector Rectangle tool and drag out a white rectangle the same size as the canvas. With the rectangle still selected:

  • Click on the down arrow of the Fill type selector and choose Gradient.
  • Choose the Waves gradient from the gradient pop-up palette (see Image XI).
  • Click in the Fill Color box to open the Gradient editor.
  • Click on the black chip and change its color to medium gray or blue.
To send the gradient-filled rectangle behind the image, choose Modify _ Arrange _ Send to Back (see Image XII).

That's it! Congratulations on a job well done. I hope you'll make much use of the techniques you learned while following this exercise.

About Linda Rathgeber
Linda Rathgeber is a writer, Web developer, and Team Macromedia member who coaches newcomers using Macromedia Dreamweaver and Fireworks. Her graphics work has been featured by the independent film company King Pictures, in book ads for author Bill Stott, in the Fireworks 4 and Fireworks MX sample files, and on the companion CD-ROMs of Joseph Lowery's Fireworks Bibles. Visit Linda at www.playingwithfire.com.

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