[Image3]:Pixels

Read Pixels

• PImage tree = loadImage(“tree.jpg”):讀取一張JPG圖片存於PImage
• get():取得整個畫面的pixel，存於PImage
• get(x,y):取得(x,y)座標的pixel，存於color
• get(x,y,width,height):取得以(x,y)為起點，(width,height)大小的區域pixel，存於PImage

Write Pixels

• image(PImage,x,y,width,height):繪製PImage以(x,y)為起點，(width,height)為大小
• set(x,y,color):設定(x,y)座標處的pixel value
• set(x,y,image):設定以(x,y)座標為起點，貼上image
• PImage.set(x,y,color):設定圖片x,y處的pixel value
• constrain(mouseX,0,50):將變數滑鼠座標X值限制在0到50之間

Exercises

• Load a image use get() to create a collage by overlaying difference sections of the same image.
• Load a image and use mouseX and mouseY to read value of the pixel beneath the cursor.Use this value to change some aspect of the image.
• Draw a shape in the display window. Copy a section of the window to another by using get() and set() within for structure.

Reference

• Casey Reas & Ben Fry : Page348