© 2022 Jasper van Baten, AmsterCHEM

Filtering your image

Your image may be noisy, or the amount of colors in your image may not match the content. You may want to use one of the filters below to fix this:

contrast and brightness

Use the contrast and brightness filter to adjust your image after it comes from the scanner. You can adjust contrast and brightness while previewing the image.

remove noise

The remove noise filter will make all colors that are similar to the background color equal to the background color. After that, it will find individual pixels that are not equal to the background color, and remove them.

You can adjust the threshold for deciding whether a pixel is equal to the background color while previewing the image.

black and white

The black and white filter is useful when you have a graph that is in two colors, and the image was scanned in gray-scales or color mode. The filter lets you adjust the threshold for black or white while previewing the image.


The flatten filter reduces the resolution per color. This is useful for images that have been scanned in gray-scale or color mode, in which only a few shades of each color are present. This filter will make those color shades equal. For gray-scale images you may want to convert to gray-scale first, if your image has been scanned in color.

You can adjust the color resolution while previewing the image.

gray scale

The gray-scale filter removes color information. This is useful for gray-scale or uniformly colored graphs that have been scanned in color mode.

invert colors

The invert color filter inverts all colors in the image. This is useful if your image has been taken from a source with a black background color.

edge filter

The edge filter highlights regions of high contrast. The effect of this is that regions on which color changes will become dark, whereas constantly colored regions are white. This filter is useful for tracking the boundaries of colored regions in graphs.

Adjusting data points
Axes definition
Background color
Bitmap file
Black and white filter
Creating a data set
Data files
Data format
Data sets
Defining your axes
Deleting data
Editing data
Erasing data
Exporting data
Filtering your image
Getting started
Graphics Interchange File format (GIF)
Gray scale filter
Highlighting edges of colored regions
Hot keys
Importing images from other applications
Inverting colors
JPEG files
Keyboard shortcuts
Lines between data points
Logarithmic axes
Manipulating data
Manually picking points
Marker color
Marker size
Moving data points
New data set
New window
Opening documents
Opening images
Pasting images
Picking points
Portable Network Graphics (PNG)
printf format strings
Reducing color resolution
Removing data
Removing noise
Resampling data
Saving documents
Saving your image
ScanIt Document files (SID)
Scanning for symbols
Scanning points on a curve
Selected marker color
Selecting data
Shortcut keys
Significant digits
Sorting data
Starting a document
System requirements
Tagged Image File Format (TIF)
Text files
Trace recursion level
Using your data in other applications
Zoom View
 Welcome to ScanIt
 The document windows
 Storing and loading documents
 The Zoom View
 Preparing your image
 Cropping your image
 Filtering your image
 The background color
 Gathering data
 Manipulating data
 Using data in other applications
 Keyboard shortcuts
 Disclaimer and license