[Image4]:Filter、Blend、Copy、Mask

Filtering 

• Filter(BLUR,parameter):高斯模糊

• Filter(POSTERIZE,parameter):色相分離

• Filter(THRESHOLD,parameter):pixel value 超過門檻就變黑低於就白

• Filter(INVERT):將每個pixel的值設成原本的inverse value

• Filter(GRAY):變灰

• Filter(ERODE,parameter):將亮的地方縮小

• Filter(DILATE,parameter):將亮的地方膨脹

規則:先畫再Filter

• line(0,30,100,60);-->BLUR
• filter(BLUR,0.3);
• line(0,50,100,80);

PImage類別有內建filter function

• PImage.filter(INVERT)

Blending

從目前畫面擷取要的地方再與原圖混合

• blend(x,y,width,height,dx,dy,dwidth,dheight,ADD)

在目前畫面中加入img，但留下兩張畫面中最暗的pixel

• blend(PImage,x,y,width,height,dx,dy,dwidth,dheight,DARKEST)

將img2加到img中

• img.blend(img2,x,y,width,height,dx,dy,dwidth,dheight,ADD)

顏色混合

• c1 = color(102)
• c2 = color(51)
• c3 = blendColor(c1,c2,MULTIPLY)
• red(c3)->102*51/255=20

複製目前畫面指定區域並貼上

• copy(x,y,width,height,    cx,cy,cwidth,cheight);

將PImage 貼到目前畫面

• copy(PImage,x,y,width,height,     cx,cy,cwidth,cheight)

PImage內建copy function

• PImage.copy(x,y,width,height,  cx,cy,cwidth,cheight)
• PImage.copy(PImage2,x,y,width,height,  cx,cy,cwidth,cheight)

Masking:原圖上加上一遮罩，此遮罩黑色部分擋住原圖(黑色，因為光線被擋住)，遮罩白色部分讓原圖顯現(中空)

在img上加上imgMask遮罩

• img.mask(imgMask);

Exercises

• Load an image and alter it with filter().
• Load three image and combine them with blend().
• Load two image and use copy() with mouseX and mouseY to combine them in a way that reveals the relationship between the images. 

Reference

• Casey Reas & Ben Fry : Page374