Improving the Quality of an Image in the Main Window Create a new thumbnail image for the main window and save to each image. The quality of images in the main window improves and images redraw themselves more quickly.
With all the images selected, select the [File] menu → [Add thumbnail to image and save].
The extent of the improvement in quality The quality is improved for any JPEG or TIFF image. While the image quality improves regardless of the thumbnail size, selecting [Large thumbnail], with its larger display size, shows the improvement more clearly than [Medium thumbnail] and [Small thumbnail].
A large number of images may take some time to add.
You can specify a presetting for JPEG images to improve the quality of all main window thumbnails. (General Settings)