Hi all. I have had a few requests recently for new images to be added in place of existing images in numista banknote listings where the added image is of poorer quality than the existing image.
I have a lot of experience in dealing with digital images, and suggest that the following guidelines be followed when making a scan of an image for substitution.
1. while banknote.ws is a good source of images, the images are of low quality and may be considered space fillers.
Any image taken from banknote.ws may be replaced - almost all the images on this website are of low quality with highlights blown out and other adjustments made, which while facilitating fast loading can alter the colour balance in the image, and will reduce the image quality.
2. Please do not replace an existing image with an image from banknote.ws unless the existing image is obviously of smaller size and quality than the banknote.ws image.
3. When replacing an image, please take note of the file size and quality of the existing image first.
4. When scanning an image of your own note, please use the following settings:
a. Scan at
- Resolution: 400dpi
- File type: .tiff
b. Save as: .jpg / .jpeg with target file size of up to 2MB on disk [=an open file of approximately 18 MB], or quality 100%. Reduce quality as far as 60% in order to keep file size below 3MB on disk.
c. No colour modification or image enhancement should be used.
d. Do not use scanning interpolation to boost the file size, scan at the scanner’s true resolution.
In interpolation, the scanner ‘guesses’ extra pixels by sampling the existing pixels surrounding the insertion point of the guessed pixel - the result is a lager file size which is slightly blurred.
These parameters will ensure that the image is of sufficient quality to enable the microprinting on modern notes to be read easily on the image.
