我对UIImage记忆规模感到不安。

1. When you have 320*320 resolution image data(png), when you load the image onto memory,
   using [UIImage imageWithData:], the resulting UIImage will take up 320*320*4?

2. 屏幕大小(分辨率)是否影响对图像的记忆使用?

3. Would the code below take up twice memory size of myImage or just single image memory size? (320*320*4) * 2 vs (320*320*4)? or something else?

   UIImage* myImage = [UIImage imageWithData:];    
   myImage = [myImage scaleToSize:];
   

   比额表 定义

   - (UIImage*)scaleToSize:(CGSize)size
   {
     // Create a bitmap graphics context                                                                                              
   
   
     // This will also set it as the current context                                                                                                                                                                                                                             
     UIGraphicsBeginImageContext(size);
   
     // Draw the scaled image in the current context                                                                                                                                                                                                                             
     [self drawInRect:CGRectMake(0, 0, size.width, size.height)];
   
     // Create a new image from current context                                                                                                                                                                                                                                  
     UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
   
     // Pop the current context from the stack                                                                                                                                                                                                                                   
     UIGraphicsEndImageContext();
   
     // Return our new scaled image                                                                                                                                                                                                                                              
     return scaledImage;
   }