Selective JPEG Mask

In general JPEG format is used for optimizing photograph. You can use JPEG to change the quality, smoothness and sharpness of an image. JPEGs optimize by throwing away information. With JPEGs you can have certain areas compressed differently than the rest of the image by using a "Selective JPEG Mask".

How to use selective JPEG mask:

1. Use the bitmap selection tools (e.g. the marquee tool) to select an area to be masked

2. Choose Modify > Selective JPEG > Save Selection as JPEG Mask

Note: You can deselect the mask selection and change the setting in the optimize window.

3. To modify the mask, choose > Modify > Selective > Restore JPEG Mask as Selection and modify the mask.

4. To remove the mask, choose > Modify > Selective JPEG > Remove Mask.
 This is the original image.

The image below shows the area which has been selected and save selection as JPEG mask.

The image below is the Optimize document which shows the setting.

The image below is the dialog box you see when clicking on the optimize button.

The Result