white spots on jpeg


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doug3fflux

Senior Member
Feb 21, 2005
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West of S'pore
Hi guys,

After scanning my negs, I view the jpegs on my laptop, and for several images there are white specks here and there.

What are they? dust?



Douglas
 

Could be dust could be the scanner algorithm itself. Try sacnning them to tiff or some other uncompressed format as they could also be compression artifacts?
 

wow, dont use so cheem technical terms..I believe its the scanner got dust? CSers who scan their negs: do you find white specks of dust on ur jpegs after scanning?
 

i dont think posting will be of any good....by the size i resize to get 100KB, its really like 3R on the screen, cant see..
 

doug3fflux said:
i dont think posting will be of any good....by the size i resize to get 100KB, its really like 3R on the screen, cant see..

Crop some affected areas?
 

arg. i not good with this bmp file stuff.

i give u link.

http://doug3fflux.myphotoalbum.com/view_photo.php?full=1&set_albumName=album05&id=F1010003_JPG

due to some 'problem' with the scanning/developing service for this particular batch of film I sent, the white specks became GREATER in QUANTITY and more WIDESPREAD across the neg. previous dev/scan dont have, only have 1 or 2 inconspicuous specks.

comment!!
 

scroll over to the right flank of the image and look at the white specks.
 

doug3fflux said:
scroll over to the right flank of the image and look at the white specks.

Looks like dust to me. I don't think it is due to any kind of numerical processing, the shapes of the spots are way too irregular.

Also, the "texture" of the scan looks a bit strange, resembling colour printing rasters. If you hadn't told us it's a scan from a negative, I would have guessed it's a scan from a book/magazine page - and the white stains would be dust and/or abrasion on the original.
 

maybe dandruff..:bsmilie: ;)

but then if u do a testshot again..see if it still appears
 

lol dandruff....can be leh..but not mine!! haha..its the guy at the photoshop...lol..
 

doug3fflux said:
so its dust? thanks for the info.

The dust theory appears most plausible to me, but I wouldn't categorically exclude other explanations. That would be unscientific.
 

LittleWolf said:
The dust theory appears most plausible to me, but I wouldn't categorically exclude other explanations. That would be unscientific.

wow thanks!
 

oaky thanks AReality and wolf. now I noe its a dusty scanning job done, because initially I could not find the root of the issue. Thanks agn.
 

so to those who employ neg scanning services, do u encounter this dusty problems?
 

doug3fflux said:
so to those who employ neg scanning services, do u encounter this dusty problems?

I'm not scanning negatives, so I cannot really comment. In the pre-digital enlarger days, one would try to keep the film, the negative stage, and the paper clean (soft brushes, clean compressed air) to get the number of dust particles down and, if necessary, retouch the prints.

If the dust doesn't come off the negative easily, it might be partially embedded into the film gelatin. Attempts to remove it from the dry film might cause more damage. Also, the dust might be in the scanner. To find out, one could compare scans from different frames in the film and see how similar the dust patterns are.
 

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