How to Reduce the File Size of PDF and Image Files

Files attached to an order within OnTime can be up to 100 KB in size. The following suggestions may assist in reducing the size of files, making it possible to attach larger files.

PDF Files

Documents that are scanned and saved as PDF files may be too large to attach. Scanning and saving the document with optimized settings can dramatically reduce the file size. The size of a PDF file is affected by these four factors:
  1. Scanning resolution
  2. Color space
  3. Physical dimension of the scanned page
  4. Compression
The following suggestions are useful when reducing the file size of scanned PDF files:
  • Lower the scanning resolution to a minimum acceptable quality level. For most applications, 150 DPI in grayscale or black and white is acceptable.
  • Use a higher level of compression. In Adobe Acrobat, choose Small Size as the Quality level. In other programs, choose a high level of compression.
  • Use the PDF Optimizer within Adobe Acrobat. This tool will help clean up, compress, and optimize the file, making it a smaller size.
  • Adobe has provided suggestions to reduce PDF file size on their Acrobat Blog.
Using these tips, scanned documents can be saved within a PDF file at about 15 KB per page, allowing for a 6-page document to be attached.

Image Files

Some images files may be too large to attach. Saving the image with more efficient settings can dramatically reduce the file size. The size of an image file is affected by these three factors:
  1. Image resolution
  2. File type
  3. Compression
The following suggestions are useful when reducing the file size of image files:
  • Lower the image resolution, also known as the size or dimensions, to a minimum acceptable quality level. For most applications, 800 X 600 pixels is acceptable.
  • Use an image file format that effectively reduces the size of the file. Avoid formats such as BMP or TIFF. Instead, save to file formats that include effective compression such as JPEG, GIF, or PNG.
  • Many programs make it possible to set the level of compression for the image. Choose a higher level of compression to further reduce file size. For example, using JPEG compression at a quality level of 15.
Using these tips, images can be saved within a JPEG file with a compression quality level of 15 at a size of 33 KB.