Tips to Solve Common
Problems Reading
Barcodes
Unlock the Information Behind Those
Bars With ImageRamp or ChronoScan
Copyright ©2014

Preprocessing
Tips for Improved
Barcode
Recognition

The best barcode recognition
starts with setting the highest
standards for your forms and
scanning workflow if possible.

Set standards for pixels per element in your barcoded forms. For 1D barcodes, at
least three pixels bar length. For 2D use modules of 4 or 5 pixels.

Set standards for pixels per element in your barcoded forms. For 1D barcodes, at
least three pixels bar length. For 2D use modules of 4 or 5 pixels.
Avoid variable length barcodes as they may force fit the code into a
fixed area. If you have to use variable length, set a maximum size
and account for that on your document.

Set standards for pixels per element in your barcoded forms. For 1D barcodes, at
least three pixels bar length. For 2D use modules of 4 or 5 pixels.
Avoid variable length barcodes as they may force fit the code into a
fixed area. If you have to use variable length, set a maximum size
and account for that on your document.
If possible, orient 1D barcodes horizontally as most scanners pull the paper
through the scanner from the shorter side. This orientation is least affected by
scan slippage that can distort the barcode.

Set standards for pixels per element in your barcoded forms. For 1D barcodes, at
least three pixels bar length. For 2D use modules of 4 or 5 pixels.
Avoid variable length barcodes as they may force fit the code into a
fixed area. If you have to use variable length, set a maximum size
and account for that on your document.
If possible, orient 1D barcodes horizontally as most scanners pull the paper
through the scanner from the shorter side. This orientation is least affected by
scan slippage that can distort the barcode.
Do not locate barcodes on forms where they may be stapled or clipped and
leave plenty of white space around barcodes, optimally ¼ inch.

Test to determine the lowest acceptable scan resolution, usually 300 dpi.
Set standards for pixels per element in your barcoded forms. For 1D barcodes, at
least three pixels bar length. For 2D use modules of 4 or 5 pixels.
Avoid variable length barcodes as they may force fit the code into a
fixed area. If you have to use variable length, set a maximum size
and account for that on your document.
If possible, orient 1D barcodes horizontally as most scanners pull the paper
through the scanner from the shorter side. This orientation is least affected by
scan slippage that can distort the barcode.
Do not locate barcodes on forms where they may be stapled or clipped and
leave plenty of white space around barcodes, optimally ¼ inch.

Test to determine the lowest acceptable scan resolution, usually 300 dpi.
Set standards for pixels per element in your barcoded forms. For 1D barcodes, at
least three pixels bar length. For 2D use modules of 4 or 5 pixels.
Avoid variable length barcodes as they may force fit the code into a
fixed area. If you have to use variable length, set a maximum size
and account for that on your document.
If possible, orient 1D barcodes horizontally as most scanners pull the paper
through the scanner from the shorter side. This orientation is least affected by
scan slippage that can distort the barcode.
Do not locate barcodes on forms where they may be stapled or clipped and
leave plenty of white space around barcodes, optimally ¼ inch.
No colored backgrounds.

Skewed Barcode

ImageRamp and ChronoScan can
read many skewed barcodes using
default settings, but some barcodes
may require adjustments to the
barcode settings.

Try setting SkewTolerance to a value between 1 and 5.
SkewTolerance controls the maximum angle from the
horizontal or vertical at which a barcode will be recognized by
the toolkit.

Try setting SkewTolerance to a value between 1 and 5.
SkewTolerance controls the maximum angle from the
horizontal or vertical at which a barcode will be recognized by
the toolkit.
The LineJump property controls the frequency with which the toolkit samples
scan lines as it moves through an image. Increasing the value of the LineJump
property will increase the speed at which an image is processed but may
decrease the read rate.

Noisy Background

With this problem, the entire
image will typically contain
black dots in the background.

Try setting the NoiseReduction to a value between 5 and 10. If a value is
specified in this setting, the toolkit will run an image through a noise
reduction filter and remove marks that are unlikely to be part of a
barcode before interpreting the barcodes. Use caution with larger values
in this setting as larger values remove larger marks from the image which
could destroy vital barcode information.

Try setting the NoiseReduction to a value between 5 and 10. If a value is
specified in this setting, the toolkit will run an image through a noise
reduction filter and remove marks that are unlikely to be part of a
barcode before interpreting the barcodes. Use caution with larger values
in this setting as larger values remove larger marks from the image which
could destroy vital barcode information.
Try setting the MedianFilter. When this setting is set to True, the toolkit
will apply a median filter to the image before checking for barcodes. This
is a useful option for high resolution images that contain speckles of
black and white. It is not recommended for images where the black bars
or white spaces are less than 2 pixels wide.

Try setting the NoiseReduction to a value between 5 and 10. If a value is
specified in this setting, the toolkit will run an image through a noise
reduction filter and remove marks that are unlikely to be part of a
barcode before interpreting the barcodes. Use caution with larger values
in this setting as larger values remove larger marks from the image which
could destroy vital barcode information.
Try setting the MedianFilter. When this setting is set to True, the toolkit
will apply a median filter to the image before checking for barcodes. This
is a useful option for high resolution images that contain speckles of
black and white. It is not recommended for images where the black bars
or white spaces are less than 2 pixels wide.
Try the UseOverSampling setting. When UseOverSampling is True
the barcode reader samples 3 lines at a time (skipping 2 lines
between each sample) and takes the average pixel value. This is
useful for images containing both black and white speckles.

White Speckles in the Bars

In this case the image will
typically contain black dots in
the background and white dots
in the black bars.

Try setting NoiseReduction to a value between 5 and
10 and Despeckle to True.

Try setting NoiseReduction to a value between 5 and
10 and Despeckle to True.
Try setting the MedianFilter. When this setting is set to True, the toolkit
will apply a median filter to the image before checking for barcodes. This
is a useful option for high resolution images that contain speckles of black
and white. It is not recommended for images where the black bars or
white spaces are less than 2 pixels wide.

Try setting NoiseReduction to a value between 5 and
10 and Despeckle to True.
Try setting the MedianFilter. When this setting is set to True, the toolkit
will apply a median filter to the image before checking for barcodes. This
is a useful option for high resolution images that contain speckles of black
and white. It is not recommended for images where the black bars or
white spaces are less than 2 pixels wide.
Try the UseOverSampling setting. When UseOverSampling is True
the barcode reader samples 3 lines at a time (skipping 2 lines
between each sample) and takes the average pixel value. This is
useful for images containing both black and white speckles.

Badly Defined Edges

In these cases the bars have
joined together in certain
places, which makes it difficult
for the toolkit to separate the
bars and determine their
relative sizes.

Try setting NoiseReduction to a value between 10 and 20.

Try setting NoiseReduction to a value between 10 and 20.
Try rescanning at a higher resolution.

Lines and Other
Marks too Close to
the Barcode

Most barcodes should have a quiet zone
around the barcode to distinguish the barcode
from the rest of the image; however, as in the
example below, it’s not unusual for barcodes
to be printed in boxes which interfere and
may result in the barcode being ignored by
the toolkit.

The LineJump property controls the frequency with which the
toolkit samples scan lines as it moves through an image. Increasing
the value of the LineJump property will increase the speed at which
an image is processed but may decrease the read rate.

The LineJump property controls the frequency with which the
toolkit samples scan lines as it moves through an image. Increasing
the value of the LineJump property will increase the speed at which
an image is processed but may decrease the read rate.
Try setting the MaxLength. MaxLength defines the largest
length for a barcode string, including checksum characters.

The LineJump property controls the frequency with which the
toolkit samples scan lines as it moves through an image. Increasing
the value of the LineJump property will increase the speed at which
an image is processed but may decrease the read rate.
Try setting the MaxLength. MaxLength defines the largest
length for a barcode string, including checksum characters.
Try setting the MinLength. MinLength defines the smallest length for a
barcode string, including checksum characters.

Learn More:

For more on:
• Batch Document processing
• Batch PDF mining
• Batch TIF mining
• Extracting meta data,
• Intelligent data capture
• Data extraction
• Document scanning
• Extracting data
• Extract meta data,
• Scanner software,
• Barcode recognition,
• Capture tutorial
• Pdf scanning,
• Scanning software
• Indexing
• Document indexing
• Automated capture
• Meta data
• Scan to index
• Docufi
• Imageramp
• Data capture
• Chronoscan
• Barcode scanning
• Improve barcode scanning
• Barcode tips
• Barcode problems
• Solve barcode errors
DocuFi
www.docufi.com
Copyright ©2014
Just escape and get
started with us.
Our solutions include ImageRamp Batch for folder processing, and ChronoScan
Capture for advanced barcode and data mining requirements.
30 years’ experience in the Document Imaging and Capture market

Image Credits
All images are owned or licensed by DocuFi with acknowledgement given to:
William Warby, “Alcatraz Cells”, Link
William Warby, “Alcatraz Cells”, Link
William Warby, “Alcatraz Cells”, Link
Lee Honeycutt, “Camp H, Cellblock”, Link
William Warby, “Alcatraz”, Link