The momma is looking for a good quality scanner that can scan transparent media, such as x-ray film. The momma does scientifical research. In her research she needs to scan x-ray images of protein blots. In order to analyze them with her computer, she needs a good scanner….
This is a protein blot. The black blobs are the protein that have been sorted by an electric field.
But that is all beside the point. For this is a list for NaBloPoMo day 3!
Random stuff about scanners (and adobe photoshop) we have learned thus far:
- Resolution: the detail of an image stated in dots per inch (dpi). Resolution can be interpolated or optical. Interpolation is a software technique that “guesses” and fills in gaps between the pixels that were actually scanned. Optical is the true resolution.
- Sharpness: The optical quality of the scanner lens and the brightness of the scanner’s light source will determine the sharpness and clarity of edges in the image.
- TWAIN: Technology Without An Interesting Name – it is the driver type used for most scanners.
- Most scanners only scan film negative sized transparencies
- OCR: Optical Character Recognition – used to capture text as.,.er,well…text, not just a photograph of text. In other words, it should be editable with a word processor.
- CCD (Charge-Coupled Device) array – commonly used for image capture in scanners. It is the main component of a scanner. More expensive, and better quality scans than CIS (next). This technology is also used in digital cameras.
- CIS: contact image sensor – newer technology than CCD. lighter and cheaper but lacking in CCD optical resolution.
- Unsharp Mask: used for sharpening photography. For graphics, “sharpen” and “sharpen more” are used. It is best when used as the last step in image processing when the specific purpose of the image is known.
- Radius: the width of the edge rims. Radius = 1.0 is best for most applications, and the better ranges are from 0.6 to 2.0. Too high of a radius setting will cause halos at edges of the objects in the image. In general, use a smaller radius for fine detail, such as facial features, and larger radii for objects.
- Threshold: the distance between tonal values before the filter will determine an edge. Facial features need thresholds of more than 1 to 2. Objects will be better with 0 to 1. The threshold in unsharp mask is different than line art threshold.
- Amount: controls brightness of the edge differences. Usually set between 80 to 120.
If you include the three subheadings of unsharp mask, this list does equal eleven, which was in the original plan.
The End!
