Reduce File Size
Revu provides a mechanism for reducing the size of some PDFs to make them more suitable 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.
Compatibility
Revu Standard, CAD or eXtreme 12.0 or higher
Contents
Reducing the Size of a Single PDF
Reducing the Size of a Single PDF
To reduce the size of a single PDF: 1. Open the PDF to be reduced.
2. From theCommandbar, go toDocument > Process> Reduce File Size. The
Reduce File Sizedialog box opens.
3. Revu comes preloaded with several convenientPresets, pre-configured settings designed to balance documentQualitywith 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: A. SelectPresets.
B. 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.
C. Proceed to step 4 below. To use custom reduction settings:
A. SelectCustom.
B. Select a previously saved custom configuration set from theEdit Presetmenu and clickOK, thenproceed to step 4 below.
or
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 originalFile Size, theEstimatedreduced 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
Images are broken into four categories according to bit depth (Full Color,8-bit Color,Grayscaleand
category is shown below each heading as theCount. Settings are applied to all images in the category.
l 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, generallyPNG1
renders images of higher fidelity whileJPEG2and
JPEG20003result in smaller image sizes. For monochrome images, CCITT generally renders the higher fidelity and JBIG2 results in the smaller image sizes.
l 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 is0, all of the images in this
category are already at a lower DPI than what is selected.
l Bit Depth: Select thecolor depth4of converted images. l Quality: Select the image quality (high,mediumorlow)
for JPEG or JPEG2000 images.
In addition, enable or disable any of the following global image settings:
l 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
1The PNG format is a lossless compressed format. The benefits to using this format are that the full quality of the
image will be retained, yet the amount of information describing the image will be reduced, generally resulting in a smaller file size.
2JPEG is a lossy compressed graphics format that drops certain graphic information entirely in the save process.
When an image is stored in this format, it will not retain all of the fidelity of the original source image, but it will produce a significantly smaller file than PNG.
3JPEG2000 is an update to the JPEG format. Compression is based on wavelet technology and creates compressed
images that generally look better than a JPEG file; the compression mechanism is more complex, however, and therefore requires more computing power to display.
smaller file size) and, if so, convert those images to the smaller bit depth type.
l Remove ICC Color Profiles: Enable to remove any
embeddedICC color profiles1, which are generally only needed when printing PDFs, and replace them with their defined, alternate color spaces.
l 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.
Fonts
l 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.
Miscellaneous
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.
l Drop Metadata: Enable to remove all metadata
associated with the PDF or with objects within the PDF.
l Drop Private Data: Enable to remove document private
data, which is generally only usable by whatever application created the PDF.
1International Color Consortium (ICC) color profiles define color spaces, data that characterizes a color input or
l Compress All Streams: Enable to compress any
uncompressedcontent streams1in the PDF.
l Drop Thumbnails: Enable to remove embedded
thumbnails, generally used for quick previews of content by some applications, from the document.
l 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).
l Drop Free XRefs: Enable to recycle anyXRefs2that no
longer refer to anything in the document.
l 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).
l Dereference number XRefs: Enable to replaceXRefs3that
reference a number (some PDFs, for example, use XRefs to define image width) with the actual number (which takes up less space).
C. To save this configuration for use in future documents:
1. ClickSaveat the top of the dialog box. TheSave Reduce File Size Optionsdialog box opens.
2. Enter a name for the configuration in theSave Reduce File Size Options asfield and clickOK.
1Content streams are the primary means for describing the appearance of pages and other graphical elements in a
PDF.
2XRefs are reference numbers for objects within a PDF. 3XRefs are reference numbers for objects within a PDF.
D. ClickOK. TheReduce File Size Custom Settingsdialog box closes. 4. To apply these file reduction settings to the PDF:
A. ClickOK. ASave Asdialog box opens.
B. Enter a name for the new PDF in theFile Namefield. 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. Be sure to provide a new file name to preserve the original PDF.
C. ClickSave. The file is compressed and saved. TheReduce File Size Results
report opens. D. ClickClose.
5. To leave the PDF in its present state, clickCancel. TheReduce File Sizedialog box closes and the file is not compressed.
Reducing the Size of Multiple PDFs (Batch)
To batch reduce the size of multiple PDFs:
1. From theCommandbar, go toFile> Batch > Reduce File Size. TheReduce File Sizedialog box opens.
2. Use one or more of the following methods to select PDFs to be reduced in size:
l Add Open Files: Click this button to add all files currently open in Revu. l Add Folder: Click this button to add all PDFs in a specified folder. ASelect
Folderdialog box will open; browse to the desired folder and click theSelect Folderbutton. All PDFs in the selected folder are added.
l Add: Click this button to add a single, specified PDF. AnOpendialog box will
open; browse to the desired PDF and click theOpenbutton. The selected PDF is added.
3. Revu comes preloaded with several convenientPresets, pre-configured settings designed to balance documentQualitywith the amount of
Compression. Use one of these presets or use customized reduction settings to determine how the selected PDFs will be compressed.
To use a preset reduction setting: A. SelectPresets.
B. Move the slider bar to the desired setting. The leftmost setting has the highest image quality and 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.
To use custom reduction settings: A. SelectCustom.
B. Select a previously saved custom configuration set from theEdit Presetmenu and clickOK, thenproceed to step 4 below.
or
-ClickEdit. TheReduce File Size Custom Settingsdialog box opens.
Reduction settings are divided among three tabs at the top of the dialog box.
Images
Images are broken into four categories according to bit depth (Full Color,8-bit Color,Grayscaleand
Monochrome) and the number of images in a given category is shown below each heading as theCount. Settings are applied to all images in the category.
l Convert to: Select the image type to convert images to.
original image type, but for color images, generallyPNG1
renders images of higher fidelity whileJPEG2and
JPEG20003result in smaller image sizes. For monochrome images, CCITT generally renders the higher fidelity and JBIG2 results in the smaller image sizes.
l 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 is0, all of the images in this
category are already at a lower DPI than what is selected.
l Bit Depth: Select thecolor depth4of converted images. l Quality: Select the image quality (high,mediumorlow)
for JPEG or JPEG2000 images.
In addition, enable or disable any of the following global image settings:
l 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.
l Remove ICC Color Profiles: Enable to remove any
embeddedICC color profiles5, which are generally only
1The PNG format is a lossless compressed format. The benefits to using this format are that the full quality of the
image will be retained, yet the amount of information describing the image will be reduced, generally resulting in a smaller file size.
2JPEG is a lossy compressed graphics format that drops certain graphic information entirely in the save process.
When an image is stored in this format, it will not retain all of the fidelity of the original source image, but it will produce a significantly smaller file than PNG.
3JPEG2000 is an update to the JPEG format. Compression is based on wavelet technology and creates compressed
images that generally look better than a JPEG file; the compression mechanism is more complex, however, and therefore requires more computing power to display.
4Number of bits used to indicate the color of a single pixel/dot.
5International Color Consortium (ICC) color profiles define color spaces, data that characterizes a color input or
needed when printing PDFs, and replace them with their defined, alternate color spaces.
l 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.
Fonts
l 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.
Miscellaneous
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.
l Drop Metadata: Enable to remove all metadata
associated with the PDF or with objects within the PDF.
l Drop Private Data: Enable to remove document private
data, which is generally only usable by whatever application created the PDF.
l Compress All Streams: Enable to compress any
uncompressedcontent streams1in the PDF.
l Drop Thumbnails: Enable to remove embedded
thumbnails, generally used for quick previews of content by some applications, from the document.
1Content streams are the primary means for describing the appearance of pages and other graphical elements in a
l 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).
l Drop Free XRefs: Enable to recycle anyXRefs1that no
longer refer to anything in the document.
l 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).
l Dereference number XRefs: Enable to replaceXRefs2that
reference a number (some PDFs, for example, use XRefs to define image width) with the actual number (which takes up less space).
C. To save these configuration settings for future use:
1. ClickSaveat the top of the dialog box. TheSave Reduce File Size Optionsdialog box opens.
2. Enter a name for the configuration in theSave Reduce File Size Options asfield and clickOK.
D. ClickOK. TheReduce File Size Custom Settingsdialog box closes. 4. To apply these file reduction settings to the selected PDFs:
A. Enter a file name suffix or prefix (or both) inSave File PrefixorSuffix, as desired. This functions like a standardSave As, adding whatever is added to these fields to the new file name for each PDF.
1XRefs are reference numbers for objects within a PDF. 2XRefs are reference numbers for objects within a PDF.
Note: If no Prefix or Suffix is added, the original PDFs will be
automatically replaced with the compressed files. No confirmation dialog box will appear. Be sure to provide a Prefix and/or a Suffix to preserve the original PDFs.
B. ClickOK. The files are compressed and automatically saved to the same folders as their originals. TheReduce File Size Resultsreport opens. C. ClickClose.
5. To leave the PDFs in their present state, clickCancel. TheReduce File Sizedialog box closes and the files are not compressed.
