Blueprint reader and takeoff tool.


Background on Imaging

Imaging developed years ago as faxing technology became usable. To send a fax, an electronic image is made of the piece of paper and then transmitted to a remote location where it is printed. FastBid uses the same imaging format and compression as fax machines. And with high resolution full scale scanners, large pieces of paper ( drawings ) can be put in with high quality. By putting the image on the web in FastBid's optimized file format, quick retrieval can then be done with a web browser.

For years people have been trying with limited success to automate the process of converting the content of the images into computer formats of programs now used to create documents. For example, when you want to write a letter, you would use a word processor to write and format the letter and then print it on paper. Optical Character Recognition ( OCR ) is the process of converting an image of a printed paper letter, back into a word processing format. Similarly, vectorizing is the process of converting an image of a drawing, back into a CAD format. OCR can work fairly well with good enough software and image quality. However vectorizing has never worked well because, unlike the alphabet, a drawing can contain an infinite number of combinations of vectors ( lines ). Vectorizing typically is no faster than redrafting a drawing from scratch, especially when quality and accuracy is desired.

Early full scale scanners were built and used with the intent of successfully vectorizing drawings to bring a company's entire collection of drawings into the computer age. Some still use vectorizing for this purpose ( with appropriate clean up effort ) but the majority of the modern use and popularity of full scale scanners is in the reprographics industry. Here the usage is straight forward. They scan the drawings once, and print them whenever they need another copy. All reprographics companys who have "modernized" or "gone digital" operate this way. Other uses for full scale imaging is archiving drawings and distribution on CDROMs. With FastBid's optimization, large images can be "distributed" on the Web, at a fraction of the cost.

Details

The format that FastBid uses is group4 compressed tiff files. Group4 compression is very effective at making the image take up much less storage than it would if it were uncompressed ( typically one 25th the space ). Group4 compression only works on bi-tone images which have one bit per pixel ( or dot ). If the bit is set, the pixel is black, otherwise the pixel is white. This way the original paper is represented as array of white pixels with certain pixels set to black to form an image. They can not store grayscale ( black and white photos ) or color information. If the resolution is high enough ( controlled by the scanner ), a one to one print will be a high quality copy of the original. We recommend a resolution of 300 dpi ( dots per inch ). Many reprographics firms use 400 dpi because copy quality is their prime concern. Many archiving operations use 200 dpi to conserve storage space. A 200 dpi image has the same resolution as a fax transmission with the quality set to fine.

When an image is displayed on screen, the initial view is of the entire drawing. To do this, the drawing needs to be scaled down to the size and resolution of the screen. All image viewers, including FastBid, use a technique called ScaleToGray. This is where the edges and corners of the lines and letters are softened by setting the color to various shades of gray ( instead of solid black ) as the image is scaled down to the screen size. This has the effect of making the screen appear to have a higher resolution than it has, increasing the clarity of the drawing. For this to work the best, setting the video settings to High Color or True Color is recommended. FastBid also has an option to control the heaviness of this effect, called ScaleToGray Contrast.

Pros and Cons of Imaging

Pros:
Any drawing or specification page can be scanned to an image. ( However, FastBid currently does not support true photographs. )
Using the web, the image can be transmitted any number of times, any distance, very cheaply.
The image display quality is much better than CAD formats because CAD viewers do not use ScaleToGray.
An image is as secure as sending paper because it is the computer's version of paper.
Sending an image is as versatile as sending paper: They can read it, measure it or copy it.
Many group4 images of drawings are smaller than the CAD version of the same drawing.
With progressive retrieval optimization in FastBid, most images retrieve and display faster than the CAD version.

Cons:
Some other formats use less storage than images.
Images can not be easily exported to other formats or manipulated. ( If you want security, this is a good thing. )
Bi-Tone imaging does not support colors like CAD does.