Tutorial: AKVIS HDRFactory

Ghost Removal in HDR Images

To create an HDR image, we need to take a series of photos with different exposures. However, while shooting, especially on a busy street, random objects (cars, people, or animals) can pass through the frame. Their appearance in each photo will be a little different. After the photos are combined, these objects will appear in various places, and due to the transparent nature of these "ghosts", the background will show through them.

Not so long ago, removing these artifacts was a time-consuming procedure. It required a graphics editor and a large amount of time. Now "ghosts" can be dealt with much more easily by using AKVIS HDRFactory.

Attention! This feature is available only under the "advanced" licenses (Home Deluxe and Business), in the After tab.

The tool works with a full-size image, it will be inactive after cropping! Use first this tool , then Crop .

To remove ghosts from the resulting HDR-image follow these steps:

• Step 1. Select the Ghost Removal tool in the Toolbar. It's used to highlight the problem part. Transparent "ghosts" will be removed in this area, keeping the object in only one state.
• Step 2. Right-click on the image to access the tool's menu. In the pop up window change the tool's size and select one of the images. This image will be used as a source for the problem area. The tool will draw with the same color as the frame of the selected image. Different objects can be marked in different colors.
  
  Select one image in set as a source image

  When choosing an image, it's recommended to choose one with the best exposure, where the object is well-visible.

• Step 3. Draw over the "ghosts" on the image. It's better to select an area a bit larger than where the ghosts are.

  Note, that you can draw only on the result in the After tab.

  After using the tool only one version of the object will remain (corresponding to selected color). The others will be deleted.

  The program will use the area from the selected image to make a resulting HDR image according to the Tone Mapping settings.

  Select area to process: Draw with color of the selected image	Result: one version of this area created on the base of the selected image

  Attention! To see the result just hide the selection by pressing !

  The process starts automatically after using the Ghost Removal tool but when the area is highlighted it's hard to see the changes.

• Step 4. If you are not satisfied with the result, you can edit the selection with the Eraser tool or choose another color (another source image) from the list and process again.