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The loop begins by getting the color value of the next pixel in the pattern array. If the color of the pattern pixel is green, the code in Listing 6 :
Compare images to see the results
If you compare Figure 4 with Figure 3 , you will see that (ignoring the skater and the ellipse) , all of the pixels in Figure 4 are darker versions of the colors in Figure 3 .
The brighter method
The Color class also provides a method named brighter which has the opposite effect. In particular, it can be used to brighten the color of apixel.
These two methods are very useful for making a pixel darker or brighter without having to know anything about the actual color of the pixel.
The else clause in the processing loop
If the color of the pattern pixel (tested in Listing 6 ) is not green, the code in the else clause in Listing 7 is executed.
| Listing 7 - The else clause in the processing loop. |
|---|
}else{
//Apply a red tint to the corresponding pixel in// the destination.
color = destPixels[cnt].getColor();
red = color.getRed();if(red*1.25<255){
red = (int)(red * 1.25);}else{
red = 255;}//end else
green = (int)(color.getGreen() * 0.8);blue = (int)(color.getBlue() * 0.8);
destPixels[cnt].setColor(new Color(red,green,blue));
}//end else}//end for loop}//end darkenBackground |
The snow scene and the ellipse only...
At this point, only the images from Figure 2 (the ellipse) and Figure 3 (the snow scene) are being processed. The image of the skater in Figure 1 hasn't entered the picture yet.
Application of the ellipse pattern
The code in Listing 7 is executed only if the pixel from the destination picture is at a location that matches one of the non-green (black) pixels in the ellipse in Figure 2 .
(The fact that the pixel is black is of no consequence. The only thing that matters is that it is not green.)
The objective of the else clause
The objective is to modify the pixel color in the destination picture at this location to give it a red tint as shown in Figure 4 .
Get, save, and modify the red color value
Listing 7 begins by getting the color of the pixel from the current location in the destination picture. It extracts and saves thered color value of the pixel. Then, depending on the current value of the red color value, it either:
Decrease the color values for blue and green
Following this, it gets the green and blue color values and multiplies each of them by 0.8.
Replace the old pixel color with the new color
Finally, it replaces the pixel color with a new color using the modified values of red, green, and blue.
The texture is preserved
As you can see in Listing 4 , this process causes the pixels in locations that match the ellipse to take on a red tint, but thetexture of the image is not destroyed as it would be if the pixels had simply been replaced by pixels that all have the same color of pink.
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