Contents: Superconducting electronics, digital photo, and home automation.

 

Scanning tips

I am using HP Photo Smart scanner mainly for negatives and slides (it is not so good for scanning prints, the cheaper flatbed scanners are doing this job better). The scanning of 35mm negative with the physical resolution of 2400 dpi gives an image of size about 3300 x 2300 pixels. At this resolution image already shows small grains due to interference with the chemically produced grains on the film. The size of these grains depends on the film sensitivity, and for the first time you scan it, this picture looks ugly. You are probably already experienced with the badly scanned pictures from magazines. This is the same story but at much higher resolution. The size of the film grain is comparable with the light wavelength, thus during making prints with the conventional technique (not using photo printer) light provides effective averaging of the color over the grains. This gives a smooth print, which we all like much. The recipe is simple, just make averaging. This will work for magazine picture too.

I am using the following procedure.
    1. Scan negative or slide at maximum resolution. There is very important feature offered by HP scanner software. It makes fast preview, which enables to see the effect of changing the scanner parameters. It is worth to spend more time finding proper parameters of scanning, than trying later to improve the image with the photo editor. Save file as BMP with 24-bit color depth (Micrografx Photo Magic).
    2. Remove dust and scratches over the all picture using Adobe Deluxe Home Edition version 3.1, which came with my flatbed HP scanner. This is amazing how this software works for small spots leaving the same image quality. For 35 mm slide scanned at resolution 2400 I am using Threshold 20 levels and Radius 3 pixels.
    3. Use Microsft PictureIt (which is came with HP Photo Scanner) to remove the rest of dust and scratches in all areas except of faces, which typically require to use cloning technique. It is important to set this software to use maximum resolution, which is not a default setting. If you don’t have Adobe software never try to remove all dust at once if you are using oldest than PictureIt99 version of the software. With PictureIt99 enlarge eyes, or other part of the image with small details, and start dust removing with the smallest dust search area. The dust clicking works amazingly in background areas, you'll enjoy it. For scratches better to use a specially designed tool than the dust remover. Don't forget to say NO when asked to save picture in one of the formats rather then BMP file if you are completely satisfied with the editing result. Use Microsoft suggested format, if you are not sure about results. This file is huge, but it keeps track of changes, which allows you step back later (not always).
    4. Use Micrografx Photo Magic (which is came with my flatbed scanner) to gently remove dust and make small color changes in faces and other important parts of composition, which can not be classified as a background ones. The main tool is copying portion of the image into another portion of the image (area cloning) using different settings.
    5. Back to Micrografx Photo Magic. Sometimes it is difficult to remove big dust spots with the PictureIt. It is good time to do this now. Than I going to the Image menu item, click Effects, Select Median method, and Amount one or two depending on the film sensitivity, and how important the small details for the whole composition. The averaging step sometime may be skipped if you were using automatic dust remove procedure in PictureIt.
    6. To save file (still in Photo Magic) use jpg file type, with the High resolution SubSampling and Compression Factor 2. This will reduce 23 Mb bmp file to the 2 Mb jpg file. Remember, if you have deleted bmp file, try to avoid jpg file editing, rescan picture instead.
    7. Add picture reference to slide presentation. Keeping only references makes your catalog smaller and faster, but require your images to be in the same folders. I also have found very useful of making 1 Mb slide presentation with PictureIt in order to send it to my friends. Than if someone ask for bigger picture I am sending bigger JPEG files.