ITEC 109 2014spring ibarland

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lab24
pictures and pixels

• Use google to find two pictures to download to your H: drive (pay some attention to where you put them — inside your 109 folder is fine; we'll be re-using them for many future labs).
• Use pickAFile to discover the exact filename of the first picture.
• Add pict1 = makePicture( someString ) to your file, and save that.
• Similarly, make a variable pict2 which holds the second picture-object.
• Try: explore(pict1)
• pickAColor
• Discuss: How colors work (rgb; )
• grab pixel at 0,7 from your pict1.
• Set its red component to 255, and its blue component to 0.
• repaint
• Do the same for pixels (1,7) to (4,7).
• Repeat for pict2.
• Next lab: make a function stripe20x10 : Picture → None which, given any picture-object, adds a blue stripe from location (20,10) up to (but not including) location (20,15); then it repaints the picture-object.

  Be sure your function works for both your pict0 and your pict1.

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©2014, Ian Barland, Radford University Last modified 2014.Mar.28 (Fri)

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