Image restoration with gain control and shoot suppression

A method of restoring an original image from an observed input image, comprising the steps of:

• performing image restoration on the input image to obtain a first intermediate restored image;
• determining a difference between the input image and the first intermediate restored image;
• performing gain control on the difference to obtain a gain controlled difference;
• determining a shoot suppression coefficient for the input image;
• applying the shoot suppression coefficient to the gain controlled difference to obtain a second intermediate restored image;
• and
• combining the input image with the second intermediate restored image to obtain a final restored image as output.

An image restoration method for restoring an original image from an observed input image, comprising the steps of:

• for each sample of the input image, determining a restored sample by image restoration;
• determining an image detail component by subtracting the input sample from the restored sample;
• applying a global gain to the image detail component to obtain a gain-controlled image detail component;
• determining a shoot suppression coefficient for the input image;
• applying the shoot suppression coefficient to the gain-controlled image detail component to generate a globally and locally controlled detail component;
• and
• adding the globally and locally controlled detail component to the input sample wherein to generate a restored sample output with gain control and shoot suppression.

An image restoration method for restoring an original image from an observed input image, comprising the steps of:

• for each sample of input image g(x,y) at coordinate (x, y), determining a restored sample r(x,y) using an image restoration process;
• determining a detail component as r(x,y)−g(x,y), and applying a global gain α to r(x,y)−g(x,y) to obtain a gain controlled detail component as α[r(x,y)−g(x,y)];
• multiplying the gain controlled detail component α[r(x,y)−g(x,y)] by a shoot suppression coefficient β(x,y) to obtain a globally and locally controlled detail component as:
• αβ(x,y)[r(x,y)−g(x,y)];
• and
• adding the globally and locally controlled detail component αβ(x,y)[r(x,y)−g(x,y)] to the input sample g(x,y) to generate a final restored image output ƒOUT(x,y) as:
• ƒOUT(x,y)=g(x,y)+αβ(x,y)[r(x,y)−g(x,y)].

An image restoration system for restoring an original image from an observed input image, comprising:

• a shoot suppression module that provides a shoot suppression coefficient β(x,y) from an input image sample g(x,y);
• and
• a gain control module that uses a global gain factor and the shoot suppression coefficient to globally control the level of image enhancement in generating a restored output image from input image, the gain control module comprising:
• an image restorer that for each sample of input image g(x,y) at coordinate (x,y), determining a restored sample r(x,y) using an image restoration process;
• a difference means that determines a detail component as r(x,y)−g(x,y), and applying a global gain α to r(x,y)−g(x,y) to obtain a gain controlled detail component as α[r(x,y)−g(x,y)];
• a multiplier that multiplies the gain controlled detail component α[r(x,y)−g(x,y)] by the shoot suppression coefficient β(x,y) to obtain a globally and locally controlled detail component as:
• αβ(x,y)[r(x,y)−g(x,y)];
• and
• an adder that adds the globally and locally controlled detail component αβ(x,y)[r(x,y)−g(x,y)] to the input sample g(x,y) to generate a final restored image output ƒOUT(x,y) as:
• ƒOUT(x,y)=g(x,y)+αβ(x,y)[r(x,y)−g(x,y)].