Get Image Changes LEADTOOLS Sample

Recently, a customer needed to find the differences between two images. More specifically the customer needed to find what changed between the two images and crop to leave only the change. From there, the LEADTOOLS OCR engine converted the cropped image to text to create a screen reader for visually impaired users. Additionally, animation and compression algorithms use similar techniques to improve performance and efficiency.

original to changed and differences

Support quickly responded to the customer with a C# console application example that finds the bounding rectangle of the differences and then crops the image.

The core function of the project finds the absolute difference between the pixels in the image. This changes all unchanged pixels to black. Because all pixels that did not change are black, the function creates a region based on color black to find the bounding rectangle of the change. Finally, the function crops the changed image to the bounding rectangle and returns the results.

static RasterImage Differences(RasterImage original, RasterImage changed)
// Make a copy of changed image for cropping later
RasterImage temp = changed.Clone();
// Get absolute difference of all the pixels
// leaving only what is different between the two
new CombineCommand(original,
LeadRect.Create(0, 0, original.ImageWidth, original.ImageHeight),
LeadPoint.Create(0, 0),
// select all non-black colors (these are all the colors that
// are different between the two images)
// Crop the original image to the bounding rectangle to
// obtain all that has changed.
new CropCommand(changed.GetRegionBounds(null))
// Free the region
// return the cropped image
return temp;

The Visual Studio C# console project can be found on the LEADTOOLS Support Forums, here:

Pre-requisites needed to run the project:

  • LEADTOOLS V19 with evaluation, Imaging Pro or better license file.
  • Visual Studio 2010 or later. (Visual Studio 2012/2013 recommended).
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LEAD Technologies: 25 years of Imaging Excellence

LEADTOOLS 25 Year Anniversary Badge

July is an awesome month. Not just because of America’s Independence or the fact that it’s National Ice Cream Month. Around here we are pretty excited because this July we are celebrating LEAD Technologies’ 25th anniversary! And starting today, we invite everyone to celebrate along with us as we will be giving away cash, discounts and other prizes!

But first, the past 25 years cannot be properly celebrated without at least a little history lesson. In the summer of 1990, Moe Daher and Rich Little started a partnership called Compression Technology. Later that year, Arthur Evans and Jim Alexander, joined as angel investors and the company transformed into LEAD Technologies, Inc. The name “LEAD” was chosen as an acronym for each of their last names: Little, Evans, Alexander and Daher.

The business started off creating a hardware compression board and DOS library to compress 24-bit TGA image files into JPEG or LEAD CMP. By 1994, Daher was awarded a patent for his invention in image compression which grew into the foundation for the early versions of LEADTOOLS.

By using LEADTOOLS, software developers didn’t have to be a genius like Daher in order to add high-performing image compression and image processing technologies into their applications. Complex tasks such as OCR, Barcode, document cleanup, DICOM, DirectShow and the like were expertly packaged into programmer-friendly libraries for multiple development environments and operating systems. LEAD’s fame and popularity continuously grew because programmers could shave off weeks, months, and even years, from their development projects and produce higher quality products in less time than if they attempted to write it all from scratch.

Once just an acronym for the company name, “LEAD” has grown and earned an even greater significance. LEADTOOLS’ motto is to be “The World Leader in Imaging SDKs,” which serves as both a true, well-earned title, as well as a testament to its founders’ hard work and vision over the past 25 years.

Celebrate with Us

  • Celebrate with Information: We’ll be releasing some little-known interesting facts about the company for the next 25 days. Of course, it wouldn’t be a celebration without some giveaways, so be on the lookout for a chance to participate and win something awesome! To be a part of it all follow @LEADTOOLS on Twitter, specifically the #LEAD25 hashtag.
    • Every day for the remainder of July, we’ll be picking one of our newest Twitter followers and Facebook fans to win a $100 Amazon gift card
  • Celebrate with Discounts: To thank our customers both new and old, we’ll be offering 25% off new or upgraded developer SDK purchases throughout the remainder of July. Use Code: LEAD25
  • Celebrate with Your Story: Share with us the coolest way you’ve used LEADTOOLS. We’ll give the best use a $2500 Visa gift card and publish the story on our blog. Ways to submit your idea:
  • Celebrate with Code: What better way to celebrate The World Leader in Imaging SDKs than to write code? We’ll be keeping the celebrations going throughout August when our LEADTOOLS Developer Support Engineers will be creating 25 apps in 25 days to celebrate and showcase LEADTOOLS’ depth of features and ease of use. Stay tuned for more information on how you can follow along!
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New White Paper: Extend Existing Applications with the LEADTOOLS Virtual Printer SDK

For July, we have published a white paper on using the LEADTOOLS Virtual Printer Driver to extend existing applications. The LEADTOOLS Virtual Printer Driver is one of the solutions LEADTOOLS provides to help developers streamline business processes and reduce human error. Additionally, the Virtual Printer Driver enables developers to connect legacy applications to new systems that reside either on location or in the cloud, even when the existing application does not include an API.

Extend Existing Applications with the LEADTOOLS Virtual Printer SDK

A common problem that faces many developers is extending existing applications when changing the underlying source code is not a possibility. As needs and systems change, there has to be a mechanism to add new functionality and maintain efficient workflows for end-users. The LEADTOOLS Virtual Printer SDK is one of several solutions LEADTOOLS provides to overcome this problem.

A Visual Studio console application project written in C# to implement a task printer based on the LEADTOOLS Virtual Printer is also available for download: LEADTOOLS V19 Virtual Printer Driver Sample

To run the example, you will need the following:

In addition to the PDF download format, we have also published this white paper on CodeProject.

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LEADTOOLS Recognition SDK – a Third-party Review

Recognition SDK

We were recently put in contact with an experienced technical blogger and web developer, Dick Strauss, about exploring the possibility of conducting a product review. He found our product line interesting and something his readers might benefit from. We were happy to partner up with him and gave him a development license for one of our most popular products, LEADTOOLS Recognition.

Not only did he navigate our documentation and rapidly implement both full-page and zonal OCR with little effort, but he found that LEADTOOLS was, in his opinion, a “stunning product” rather than just a “good functional product.” He experienced the entire process of using LEADTOOLS, including unlocking support with his development license, starting a project from scratch, and firing off some questions to our outstanding support department.

Click the link below to read the whole post:

LEADTOOLS Recognition Imaging SDK: Create Imaging Apps Easily
   — from

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LEAD Wins 2015 SD Times 100 Award

For the fourth consecutive time, LEAD Technologies has won an SD Times 100 award in recognition of its outstanding family of imaging toolkits, LEADTOOLS. This year, LEADTOOLS won in the coveted APIs, Libraries & Frameworks category. We are proud to once again be a part of this prestigious group of companies through hard work and dedication to making LEADTOOLS the World Leader in Imaging SDKs.

Each year, the editors of Software Development Times seek to pinpoint companies and products who demonstrate innovation and leadership in several key categories driving the software development markets including APIs, Libraries & Frameworks, Big Data, Database, Cloud, User Experience, and more. To see a list of all winners from all categories, read the original article from SD Times.

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