Images in the PDF look worse than the original image
Product
Version
Server DocConverter WebGrabber
3.5.2
Description
The quality and file-size of an output PDF is directly related to the whole-file resolution and related image quality settings applied to the file during conversion. These options are found in the Configuration Editor or can be controlled programmatically via the related Properties. By altering these settings, you can control your output to find a median between resultant file size and quality.
NOTE: We strongly recommend that you restart the Print Spooler service after changing these settings.
Details
Resolution
The number of Dots Per Inch (DPI) in the whole file. Quality and file size increase with the DPI setting.
Default Color Image Flags
The following settings are available:
Option
Description & Settings
Image Sampling
The sampling method applied to the image. Available options are:
No Sampling: Highest quality. File size and quality is determined by the original image.
Average Downsample: File is downsampled to the Resolution by locating similar groups of pixels, averaging the appearance, and then combining the result into a single pixel.
Subsample Downsample: File is downsampled to the Resolution by locating a common pixel in a sample area and then removing the surrounding pixels.
Image Compression
The compression scheme applied to the image. Available options are:
No Compression: Highest quality. Nothing is compressed. Images retain original compression. File size and quality is determined by the original image.
High JPEG Compression: Images are converted to JPEG for compaction. Lowest level of JPEG compression produces larger resultant file sizes with higher quality.
Medium JPEG Compression: Images are converted to JPEG for compaction. Intermediate level of JPEG compression produces average resultant files sizes with average quality.
High JPEG Compression: Images are converted to JPEG for compaction. Highest level of JPEG compression produces smaller resultant file sizes with lower quality.
Flate Compression: Text data in the PDF is compressed and images retain original compression. File size and quality is determined by the original image.
Predictor Compression: Uses the existing compression index to only handle uncompressed data offering slightly faster compression. File size and quality is determined by the original image.
Resolution
The number of Dots Per Inch (DPI) in the image. Quality and file size increase with the DPI setting.
Default Grey Image Flags
The following settings are available:
Option
Description & Settings
Image Sampling
The sampling method applied to the image. Available options are:
No Sampling: Highest quality. File size and quality is determined by the original image.
Average Downsample: File is downsampled to the Resolution by locating similar groups of pixels, averaging the appearance, and then combining the result into a single pixel.
Subsample Downsample: File is downsampled to the Resolution by locating a common pixel in a sample area and then removing the surrounding pixels.
Image Compression
The compression scheme applied to the image. Available options are:
No Compression: Highest quality. Nothing is compressed. Images retain original compression. File size and quality is determined by the original image.
High JPEG Compression: Images are converted to JPEG for compaction. Lowest level of JPEG compression produces larger resultant files sizes with higher quality.
Medium JPEG Compression: Images are converted to JPEG for compaction. Intermediate level of JPEG compression produces average resultant files sizes with average quality.
High JPEG Compression: Images are converted to JPEG for compaction. Highest level of JPEG compression produces smaller resultant files sizes with lower quality.
Flate Compression: Text data in the PDF is compressed and images retain original compression. File size and quality is determined by the original image.
Predictor Compression: Uses the existing compression index to only handle uncompressed data offering slightly faster compression. File size and quality is determined by the original image.
Resolution
The number of Dots Per Inch (DPI) in the image. Quality and file size increase with the DPI setting.
Default Monochrome Image Flags
The following settings are available:
Option
Description & Settings
Image Sampling
The sampling method applied to the image. Available options are:
No Sampling: Highest quality. File size and quality is determined by the original image.
Subsample Downsample: File is downsampled to the Resolution by locating a common pixel in a sample area and then removing the surrounding pixels.
Image Compression
The compression scheme applied to the image. Available options are:
No Compression: Highest quality. Nothing is compressed. Images retain original compression. File size and quality is determined by the original image.
Flate Compression: Text data in the PDF is compressed and images retain original compression. File size and quality is determined by the original image.
Predictor Compression: Uses the existing compression index to only handle uncompressed data offering slightly faster compression. File size and quality is determined by the original image.
CCITT Compression: Recommended. Image is handled as a series of lines, where each line is encoded based on the previous line for optimal compression ratios.
Resolution
The number of Dots Per Inch (DPI) in the image. Quality and file size increase with the DPI setting.
The information in this article is for the use of activePDF Customers and Evaluation Users Only. No part of this document may be transmitted or reproduced without the express written consent of activePDF.
Server