OT digital photography / touch up question

[Guest Anonymous]

I have an image which was scanned that is ~ 1mb. There is a blemish on the photo. When I bring into a program like paint, corel, dell pro paint etc and touch up the resave image drops to 200kb.

Tried everything but can get it to maintain the 1mb file size? In as Jpeg out as Jpeg.

[Guest Anonymous]

if it is saving at 200 kb, then try opening the image

after you save it and see if it is the original 1 mb or

if the image size/resolution was reduced. if you

save the photo as a tiff then there isn't any

compression and it remains the original file size.

let me know if that works.

mike

[Guest Anonymous]

i've never had this problem with photoshop 4-7

[Guest Anonymous]

(nt)

[Guest Anonymous]

I'm not familiar with your software, but when you save as a

jpg, you should be able to choose how much compression is

allowed. Jpeg is a "lossy" form of compression - every time

you save it as such, a little more sharpness is taken out of the

photo, determined by an algorithm. Are you given a choice

when you 'save as' for quality - say on a 1 to 10 scale?

Also, when you 'save as', is tiff a choice for file type? A tiff

won't compress the way a jpg does, so you won't lose any

detail.

One more thing: Photoshop LE (a light version) is often

included with digital cams. If you have it, definately load it up;

it's the best bang for the buck out there. If not, you can

download a freebie version with a time sensitive license:

http://www.adobe.com/products/tryadobe/

main.jhtml#product=40

Photoshop is really intuitive and will save files as tiffs.

[Guest Anonymous]

(nt)

[Guest Anonymous]

Does this mean that everytime you save a JPEG the image gets more and more compressed?

[Guest Anonymous]

You can't really say a image will get smaller each time you save it with jpeg compression. I won't get into why, but go off on a tangent that is much more important.

JPEG is a lossy compression. Some of the original image info is tossed. The image will never return to its original after compression. However your eye is a wonderful thing, you normally don't realise this.

JPEG compression creates 'artifacts' in the image. This is visual information not in the original image. Normally your eye blends these and the image looks correct. When you can see them they are pretty obvious. They show up as square edged blocks of colors that look artificial (computer generated). 2 reasons these show up. One, the original image was over compressed, or, and this is the important one for you, the image was jpeg compressed multiple times. JPEG artifacts are additive. Meaning if you compress a jpeg image again, the artifacts will become more prevelant until they are easily visible.

You can see this by opening a jpeg and resaving it over itself a few times. Then view it again. It should look pretty 'jagged'. A low contrast image will really show artifacts with very little compression.

hth

david