Tuesday, June 13, 2006

Image Processing vs. No Imaging Processing. . .

I have been wrestling with the best way to present the Hunter's Call. The original copies are very old and worn. The paper is very brown and in many cases, is falling apart. I originally thought the best way to present the issues would be to scan as multipage .tiff files in 24 bit color @ 300 dpi. Once the scanning was completed, I would then apply image processing (i.e. thresholding and/or color dropout). Thresholding is an image processing option that Kofax VRS takes advantage of for forms scanning. Basically, scanning is done in grayscale and then thresholding is applied to turn the image black and white but the text appears much more clearly vs. if the document was scanned originally in black and white. Simply put, thresholding can better interperate differnent shades of color and gray when scanning as oppsed to just a black and white scan. Color dropout allows the operator to "select" the brown paper color and remove it from the image leaving a white background. This helps make an older document look brand new. There are trade offs when applying these two image processing options for the Hunter's Call. Photos on pages with color dropout applied look more like the original photos but the text is not as clear. For pages with thresholding applied, the text is much more sharp but the photos on the page look like they are a Xerox copy. I forgot to add, applying image processing for these files takes a long time becuase the original files are very large-uncompressed .tiff images.

I presented the different images to Rich Tibbetts and he liked the originals with the brown. The bottom line, we don't have to worry about image processing anymore so the point is mute.

Here are examples of the various image processes. . .

"Original" "Color Dropout" "Thresholding"

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