TIFF Size Compressed by 60% in Dynamic Web TWAIN v14.3.1
Dynamic Web TWAIN v14.3.1 introduced a new compression algorithm to the TIFF format. When a user exports scanned documents to a one-page or multi-page TIFF file, the size will now be reduced by 50%~60%. Some early adopters expressed appreciation for this update:
“With this version, the scanned documents are approximately 64% smaller than with version 14.3 — incredible!”
How is it implemented?
With computer images, RGB is the most common color model — each color expressed as a triplet (r,g,b). The triplet component values are often stored as integer numbers in the range 0 to 255. So each pixel needs 3 bytes. With the YCrCb color encoding system, it saves one 8-bit luma component for every point and two chroma values — a Cr value and a Cb value — every 2x2 points. So, using the RGB model, 4 points need 4x3=12 bytes, while with YCrCb, 4 points need only 4+2=6 bytes. Each point takes up 12 bits on average. Since the human eye is much more sensitive to the luminance change (Y) than the chroma change (CrCb), YCrCb color model can reduce the file size without diminishing quality to the naked eye. Dynamic Web TWAIN v14.3.1 used YCrCb color model to compress the TIFF file.