Android image processing (3) Negative effects

This article will deal with the effect of film effects. As before, the pixel is processed, and the algorithm is universal.

Algorithm principle: The RGB value of the current pixel points and the difference of 255 respectively as the current point of the RGB value.

Cases:

Abc

To find the negative effect of B point:

B.R = 255-B.R;

B.G = 255-B.G;

b.b = 255-b.b;

：

Original

Code:

[Java]View PlainCopy

2. Package com.color;
6. Import Android.content.Context;
8. Import Android.graphics.Bitmap;
10. Import Android.graphics.BitmapFactory;
12. Import Android.graphics.Canvas;
14. Import Android.graphics.Color;
16. Import Android.graphics.Paint;
18. Import Android.util.AttributeSet;
20. Import Android.widget.ImageView;
24. Public class Colorview extends ImageView {
28. private Paint mypaint = null;
30. private Bitmap Bitmap = null;
32. private int width,height;
34. private int[] oldpixels;
36. private int[] newpixels;
38. private int color,color2;
40. private int pixelsr,pixelsg,pixelsb,pixelsa,pixelsr2,pixelsg2,pixelsb2;
44. Public Colorview (context context, AttributeSet attrs)
46. {
48. Super (context, attrs);
50. Bitmap = Bitmapfactory.decoderesource (Context.getresources (), R.DRAWABLE.WW);
52. width = Bitmap.getwidth ();
54. Height = bitmap.getheight ();
56. Oldpixels = new int[width*height];
58. Newpixels = new int[width*height];
60. Invalidate ();
62. }
64. @Override
66. protected void OnDraw (canvas canvas) {
68. Super.ondraw (canvas);
70. //Get pixels
72. Bitmap.getpixels (Oldpixels, 0, width, 0, 0, width, height);
76. For (int i = 1;i < height*width; i++) {
78. color = Oldpixels[i];
80. //Get RGB components
82. Pixelsa = Color.alpha (Color);
84. PIXELSR = Color.Red (Color);
86. PIXELSG = Color.green (Color);
88. PIXELSB = Color.Blue (Color);
92. //Conversion
94. PIXELSR = (255-PIXELSR);
96. PIXELSG = (255-pixelsg);
98. PIXELSB = (255-pixelsb);
100. //Both are less than or equal to 255 greater than or equal to 0
102. if (PIXELSR > 255) {
104. PIXELSR = 255;
106. }
108. Else if (PIXELSR < 0) {
110. PIXELSR = 0;
112. }
114. if (pixelsg > 255) {
116. PIXELSG = 255;
118. }
120. Else if (PIXELSG < 0) {
122. PIXELSG = 0;
124. }
126. if (pixelsb > 255) {
128. PIXELSB = 255;
130. }
132. Else if (PIXELSB < 0) {
134. PIXELSB = 0;
136. }
138. //Generate new pixels based on new RGB
140. Newpixels[i] = Color.argb (Pixelsa, PIXELSR, PIXELSG, PIXELSB);
144. }
146. //Create new picture based on new pixel
148. Bitmap.setpixels (Newpixels, 0, width, 0, 0, width, height);
150. Canvas.drawbitmap (Bitmap,0,0,mypaint);
152. }
154. }

Android image processing (3) Negative effects