How to Scan Images
In this section you will learn how to use a flatbed scanner to digitize an image from a printed medium and save it for later use.
In order to scan an image make sure you have the following:
- Flatbed scanner
- Object to be scanned
Steps to Resolution
This guide is focused with simple and effective ways to scan an image. It does not address other related items such as how to setup and install a new scanner. Please refer to the product setup/installation guides that came with the device for further details on these steps.
There are multiple ways to scan an image depending on what type of scanner hardware you're using and what software is available on the computer its attached to. These directions focus on some of the easier and more consistent methods using software that is commonly available accross the UAA campus.
- Launch Adobe Photoshop
- Click File, then click Import, and then HP ScanJet XXXX TWAIN (where XXXX is the model of the scanner attached to the workstation). If the scanner model is a brand other than HP please substitute the appropriate make and model for the scanner you're using in these instructions.
- The HP Scanning software will start, after it finishes loading you should see something like the following window.
- You can now use the HP Scanning software to resize and/or reposition the area you would like to scan. When the region you want is selected click Accept.
- Once your scan completes it will be imported into Photoshop, now select File -> Save (or Save As).
- From the Save dialog, select the drop-down box marked Format, scroll down and select the most appropriate one for your needs and then click save.
Choosing an Image Format
There are many image file formats available, which one to use is dependent upon your specific need/use. Below are some of the most common and their typical uses. The most commonly used are JPEG, TIFF, PNG, and GIF.
When saving initial scans it is usually recommend to go with a format that preserves the best image quality such as TIFF or Photoshop's native format since the image can always be resaved as a different image type or rescaled to reduce the file size.
- Bitmap (.bmp): Commonly used by MS Windows & programs. Usually uncompressed image, but relatively large file size.
- GIF (.gif): Was designed in the days of 8-bit computer video and dial up modem speeds. It is always an indexed color file (8-bits, 256 colors maximum), which is a poor choice for 24-bit color photos. PNG, or TIF is a more versatile choice. GIF can still be a very good choice for web graphics with a limited number of colors and can be much smaller file size than JPG.
- JPEG (.jpg/.jpeg): Commonly used for photos. Relatively small file size. Image quality varies greatly depending on settings due to lossy compression. This file type is used when small file size is more important than maximum image quality (web pages, email, memory cards, etc). JPG is good enough in many cases as long as compression is not overdone (i.e. use higher image quality settings).
- Photoshop (.psd/.psb): Default format for Photoshop. Has many extra features such as image layering.
- PNG (.png): Image format with lossless compression. Designed as a replacement to GIF format and offers many of the same options as TIFF.
- TIFF (.tif/.tiff): Used extensively for traditional print graphics. Lossy & Lossless file compression. Variable file size depending upon settings. Is considered the highest quality format for commercial work and is the most versatile, except that web pages don't show TIF files. For other purposes however this format does almost anything you might want.
Maintaining Image Quaity
If you're concerned with maximum quality for archiving your important images you need to be aware of few things:
- You should always save your original scan in a lossless format such as TIFF or Photoshop native .psd.
- When saving to JPG you should always choose the higher quality setting, this does typically result in a larger file size.
- If you have a choice betwen GIF and PNG, PNG is usually, but not always, the better choice.
- Do not keep editing and saving your JPG, or other lossy, images repeatedly, because more quality is lost everytime you save it (in the form of added artificts... pixels become colors they ought not to be, etc). You should always go back to the original lossless saved file for all editing and do a save as and give it a new name and select an appropirate file type based on the planned use of modified image.