Automatic crop – Threshold maximum value

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cday
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Automatic crop – Threshold maximum value

Post by cday »

In XnConvert the maximum Threshold value that can be entered is limited to 99, lower than the maximum value that can be used in XnView or NConvert. In my experience there are situations where higher values — even perhaps improbably high values — can be useful.

Automatic crop is a very useful function when cleaning up scans of book or magazine pages, and when followed by a canvas resize enables the image to be accurately centred on a clean canvas.

When using auto crop even a very small dark spot on the canvas outside the wanted part of the image can prevent the image being cropped correctly, but when the wanted image is good quality a high threshold value does not prevent it being auto cropped correctly.

C.
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xnview
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Re: Automatic crop – Threshold maximum value

Post by xnview »

ok, i'll change...
Pierre.
cday
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Re: Automatic crop – Threshold maximum value

Post by cday »

The Automatic crop user interface now has space for three digits but the maximum Tolerance value that can actually be entered remains at 99...

The operation of the Automatic crop function -- the selection of Background colour and Tolerance values -- is perhaps not well understood, but the higher Tolerance values available in XnView do seem to be useful sometimes.