This dialog box will be displayed when saving a file to a JPEG file format.
Quality. Select a quality value, between 20 and 100. Values between 50 and 95 are recommended. Values below 25 are likely to degrade the image far too much, and values above 95 make the file larger without any appreciable quality increase.
Use original quality. Check this option to use the JPEG quality from the original image.
Smoothing. This option is sometimes useful for storing dithered 256-color images as JPEGs; it attempts to smooth the differences between pixels caused by dithering, but tends to blur the image somewhat.
Sub-sampling. Use this drop down list to control the amount of color information that will be shared by consecutive pixels. For more information on JPEG sub-sampling click here.
Preview. Allows you to see the effect of the lossy compression on the image. You may scroll this preview around to different parts of the image to see the effect on specific details. The Delta option shows the differences between pixels, before and after compression. Medium gray is "zero difference".
Note: A truecolor or highcolor (24-bit or 16-bit) display driver is required to utilize the JPEG loss preview.
File size. If checked, ThumbsPlus will display the computed file size using the selected JPEG quality settings.
Note: You may want to uncheck this option when saving very large files to avoid the file size computation.
Progressive JPEG (standard scan sequence). Check this option to store the JPEG as a Progressive JPEG (not recommended).
Remove file information (EXIF, IPTC). Check this option to store the JPEG without the original EXIF and IPTC/NAA information.
Suppress JFIF header. Check this option to exclude the JFIF file header.
Note: Some digital cameras will not recognize JPEG files with JFIF headers and therefore cannot display them in the LCD preview display. If you are storing images back to your digital camera and are having trouble seeing the resultant images, try checking this option.