What is file optimization?
What does NXPowerLite do to my files?
Files are often much larger than they need to be. NXPowerLite makes them smaller by removing any excess baggage and converting graphics to the most appropriate file format and resolution. Optimized files remain in their original format, and will be visually and functionally the same as the original. They don't need to be decompressed or rehydrated, and there's no need for special viewing software - so they can be opened and edited by anybody. File optimization is "lossy" by design, and below is a list of examples of how it reduces the size of each file type:
PDF (including all sub-sets)
Convert inserted images to the most efficient file format Adjust the JPEG quality of images Resize inserted images to the most appropriate size Remove cropped areas of inserted images Remove private application data
PowerPoint, Word and Excel
Remove unnecessary metadata Remove “fast save” information Convert inserted images to the most efficient file format Adjust the JPEG quality of images Resize inserted images to the most appropriate size Remove cropped areas of inserted images Flatten embedded documents JPEG: Adjust the JPEG quality of images without resizing them
Apply lossless LZW compression to TIFF files containing only uncompressed images. For multi-page TIFF files NXPowerLite will apply lossless LZW compression to uncompressed pages.
NXPowerLite's PNG optimization is actually a color quantization process. It will convert each PNG images to 8-bit colour and this process reduces file sizes significantly (often as much as 70%) and preserves full alpha transparency. Generated images are compatible with all web browsers and operating systems.
Please note: Any of the above files found in a Zip file can be extracted and replaced with smaller versions as described above. Once processed all the files will be re-compressed leaving a file that looks like the original Zip just smaller.
How much smaller will my files get?
How much smaller your files get will depend on how many graphics and embedded documents they contain, and how large they are initially. Users have experienced compression rates as high as 99% with no discernible loss of quality to their files. However, if your files contain no graphics or embedded documents, they are unlikely to get much smaller.
For example, NXPowerLite is likely to get much better reduction results with large image-heavy PowerPoint files rather than small data-heavy Excel files.
Can I still edit a file after it has been optimized by NXPowerLite?
If I send a file optimized by NXPowerLite to somebody, do they need NXPowerLite to open it?
Will the 'Compress Pictures' feature in Microsoft Office achieve the same results as NXPowerLite?
What's the difference between optimization and compression?
File optimization can reduce file sizes far more effectively than traditional compression methods, such as zip compression. Optimizing an image-heavy PowerPoint presentation will often reduce its file size by 90% or more (zipping the same presentation will result in a compression rate of just 10-15%). And, as optimized files remain in their original format, there's no need to unzip a file before using it.
Can I re-optimize my file?
By default NXPowerLite will not reduce a file unless it has changed by +/- 64KB or the optimization settings used are more aggressive than the original settings used. 'More aggressive' could mean lower image quality, smaller resolution or optimization of hidden data elements.
The reason behind this feature is that NXPowerLite needs to ensure that files are not over-optimized. This can create pixelated images and unusable content. So NXPowerLite leaves a small amount of metadata in each file that is successfully processed. It can then decide what to do and apply the rules outlined earlier.
What does 'Flatten embedded documents' mean?
Enabling this feature will cause embedded objects within Office files to be "flattened", converting them into pictures. This will reduce the size of the files but users will no longer be able to double-click embedded objects to edit them.
For example, a PowerPoint presentation may contain an embedded Excel sheet with a table of figures. Double-clicking the table would normally open Excel to edit the figures, but flattening the document converts the table to a simple picture, meaning the underlying data cannot be edited.
If NXPowerLite has "flattened" embedded objects then a message will be shown under the file name in the Results window. To optimize files without "flattening" embedded objects choose one of the "no flattening" Optimize profiles or a custom profile.
What does 'Delete private application data' mean?
Will my optimized files have the same creation date and time as the originals?
By default, all of NXPowerLite's software products are configured to keep the same creation date and time as the original files. This ensures that all the relevant metadata is present in the file after optimization. NXPowerLite Desktop can create additional copies or backup files and in these cases, you can choose how the date and time settings are configured. This is available in the preferences menu option.