Reduce File Size
Revu provides a mechanism for reducing the size of some PDFs to make them more palatable for email or a Document Management System. This tool works by compressing bitmap images and removing non-visible document data. It does not affect vector content. Be aware that performing this action on a page containing flattened markups will prevent all markups on the page from being unflattened.
The Reduce File Size feature for single PDFs is discussed here. There is also a Batch version of Reduce File Size.
Reducing the Size of a PDF
To reduce the size of a single PDF:
- Open the PDF to be reduced.
- Go to Document > Process > Reduce File Size. The Reduce File Size dialog box appears.
Revu comes preloaded with several convenient Presets, pre-configured settings designed to balance document Quality with the amount of Compression. Use one of these presets or use customized reduction settings to determine how the PDF will be compressed.
To use a preset reduction setting:
- Select Presets.
- Move the slider bar to the desired setting. The leftmost setting has the highest image quality with the lowest amount of compression while the rightmost setting applies the highest amount of compression resulting in the greatest size reduction, though possibly at the expense of image quality.
- Proceed to step 4 below.
To use custom reduction settings:
- Select Custom.
Select a previously saved custom configuration set from the Edit Preset menu and click OK, then proceed to step 4 below.
- or -
Click Edit. The Reduce File Size Custom Settings dialog box appears.
Reduction settings are divided among three tabs at the top of the dialog box. Before beginning, however, consult the color-coded bar chart at the bottom of the dialog box. It shows a breakdown of the PDF’s file size and can indicate where the most dramatic file reductions can be realized. This is also where the values for the original File Size, the Estimated reduced file size and the percentage by which the document will be reduced are shown. These values update as settings are changed; use them to determine whether the selected configuration meets the file reduction needs.
Images are broken into four categories according to bit depth (Full Color, 8-bit Color, Grayscale and Monochrome) and the number of images in a given category is shown below each heading as the Count. Settings are applied to all images in the category.
- Convert to: Select the image type to convert images to. The effects of this selection vary greatly according to the original image type, but for color images, generally renders images of higher fidelity while and result in smaller image sizes. For monochrome images, CCITT generally renders the higher fidelity and JBIG2 results in the smaller image sizes.
- Max DPI: Select the maximum number of Dots Per Inch (or “resolution”) to convert images to. The number of images that would be reduced by the selection is shown below the selection. If this value is 0, all of the images in this category are already at a lower DPI than what is selected.
- Bit Depth: Select the of converted images.
- Quality: Select the image quality (high, medium or low) for JPEG or JPEG2000 images.
In addition, enable or disable any of the following global image settings:
- Automatically reduce bit depth of compatible images: Enable to cause all images selected for conversion (above) to be analyzed to determine whether they can be converted to a smaller bit depth without introducing errors (for example, some images saved as "full color" would do just as well saved at "8-bit color" with a considerably smaller file size) and, if so, convert those images to the smaller bit depth type.
- Remove ICC Color Profiles: Enable to remove any embedded , which are generally only needed when printing PDFs, and replace them with their defined, alternate color spaces.
- Combine identical indexed colorspaces: Enable to cause all images that use identical color spaces to reference a single instance of the color space in the PDF and remove the duplicates.
- Drop Embedded: Enable to remove any embedded fonts from the PDF. Note that this might affect the display of the PDF on other computers; if a font used in the PDF is not present on another computer, a substitute font will be used to render the PDF.
Enable any of the following options, as desired. The general effects of selecting an option (for example, the number of bytes that would be removed from the file or the number of images that would be affected) is shown immediately to its right; if nothing is shown, that type of data is not present and enabling the option would have no effect.
- Drop Metadata: Enable to remove all metadata associated with the PDF or with objects within the PDF.
- Drop Private Data: Enable to remove document private data, which is generally only usable by whatever application created the PDF.
- Compress All Streams: Enable to compress any uncompressed in the PDF.
- Drop Thumbnails: Enable to remove embedded thumbnails, generally used for quick previews of content by some applications, from the document.
- Drop Unused Resources: Enable to remove any resources, such as images, fonts, color spaces, or snapshots of content from other pages, that are not used when rendering page content (this often happens when PDFs are extracted from larger documents).
- Drop Free XRefs: Enable to recycle any that no longer refer to anything in the document.
- Crop content to crop box: Enable to remove any image data that falls outside of a PDF's crop box (often when an image is "cropped" within a PDF, the parts of the image that fall outside the crop box are simply hidden; this option deletes the hidden content).
- Dereference number XRefs: Enable to replace that reference a number (some PDFs, for example, use XRefs to define image width) with the actual number (which takes up less space).
- To save this configuration for use in future documents:
- Click Save at the top of the dialog box. The Save Reduce File Size Options dialog box appears.
- Enter a name for the configuration in the Save Reduce File Size Options as field and click OK.
- Click OK. The Reduce File Size Custom Settings dialog box closes.
- To apply these file reduction settings to the PDF:
- Click OK. A Save As dialog box appears.
- Enter a name for the new PDF in the File Name field. If desired, browse to a new location to save it (by default, Revu will save it in the same folder as the original).
Note: If you do not specify a new name, a dialog box will appear asking for confirmation that the original PDF should be replaced with the compressed file.
- Click Save. The file is compressed and saved. The Reduce File Size Results report opens.
- Click Close.
- To leave the PDF in its present state, click Cancel. The Reduce File Size dialog box closes and the file is not compressed.
Batch Reduce File Size