Many of poor quality scans were created on expensive large format scanners whose product literature glows with the promise of quick and easy high quality scans. Though as the scans we receive show, there is no assurance of useful results when the scanner is used inappropriately for the drawing in hand.
This article sets out simple steps for ensuring high quality scans. It is intended most specifically at users wanting to scan drawings for raster to vector conversion but once you have mastered this relatively simple process that largely a matter of learning to read your drawings and to use your scanner correctly that you will also be able to apply the improvements in image quality to the archiving of important drawings in order to give them and posterity the quality they deserve.
Defines a high quality or poor quality scan?
A high quality scan is one where the lines, arcs and text are clear, clean and unbroken, some places close together entities are separated by clean white space and where curves are smooth.
Examples of high quality scans that can be converted by using a raster to vector converter:
- High quality scans comprising unbroken bodies and smooth curves. Text characters and parallel bodies are separated by clean white space.
- A poor quality scan is one where the lines, curves and text are broken.
- Poor quality scans are blurry or are impossible to read even to the human eye though have merged together.
- While some poor quality scans can be mended that using raster editing tools, several cannot. In this case, the scans cannot be converted using automated raster to vector conversion and the only course open to you if you need the drawings in vector format is to return to the drawing board / PC CAD system to redraw the image, or to rescan the original paper drawing if you still have it.
Examples of poor quality scans that perhaps one is mendable:
- Some are unsuitable for screening and printing, let alone raster to vector conversion. These are all real scans we have received.
- Entities are blobby and have merged into each other. Entities are broken and parts of the image are missing altogether. The lines have holes in them. Entities are blurred and have no definition. Entities are broken and are impossible to read even to the human eye.
There are two different types of images used by graph design programs. Like- raster images (sometimes called “bitmap image“)and vector-based images.
There are many service those are raster based as well as vector. Such as- Photo Editing, Illustration, Logo Design, Brochure Design, Book Cover Design, Leaflet Design, Billboard Design etc.
Photo Editors are Raster Based
A raster image is made of thousands of little dots or pixels. Creating or editing an image with dots allows you to provide for rich detail in an image. Because every dot can be a different color, you can allow for any kind of color change.
Raster images are wonderful for rendering rich, full-color images, like photographs. Raster-based programs do have some drawbacks, though Raster images are heavy file. All of the zeros & ones those are used to make up each pixel result in large files sizes. Your computer must keep track of the zeros and ones and must change each one when editing. This is memory-intensive and may cause slower editing.
Raster does not resize well. When you resize a raster image, the pixels just get larger, making the image appear distorted and thickly or grainy. Photo editors, like Adobe Photoshop that use raster based images to allow for precise editing and total freedom in image form.
Illustration Programs are Vector Based
Vector based programs approach image creation in an completely different manner. A vector-based program does not create images on a pixel by pixel base.
In a raster basis image creation program, a cube would be made of thousands of pixel dots.
In a vector based program, the same square would be made of only four dots, one on every corner. These vector points mainly allow your computer to play connect the dots. Every vector point has information in it telling your computer how to connect each point with straight or curved lines, and with what color to fill in the closed outline.
In the printed image, the vector points would be unseen. Because the computer has only to keep four points in its memory, it is much easier for the computer to edit vector based images. If you resize a vector based image, it loses little or no detail. The vector points spread out and the computer just redraws the image. You can easily fill color, or recolor, a vector-based image very easily using a drawing program. Vector images can also result in smoother lines because the lines are not tender drawn.
Vector images do have some drawbacks, however. They are normally filled with a solid color or a gradient but can’t display the lush color depth of a raster. They also work better with straight lines or extensive curves. Drawing plans, like Adobe Illustrator and Macromedia unguided that primarily use a vector-based drawing mode to allow for scalability and clean lines.
If you need more information then you can contact us at info@clippingpathzone.com or skype: clippingpathzone