Hi All

let me tell you a little about me, I've been playing with digital photography since 96'
Here's my question.... I have a 2 4x6 images that make up a panorama. I need to scan these images and stitch them together which will result in an image on final output to be 20 x 68 @ 400 dpi printed on a plotter

My problem is I've scanned the images at 400 dpi and each image @ about 20 x 34 which leaves me a file the size of 270 + mb each. This is too much for my computer and PS2 to handle.

I recall somewhere that I can scan an image at higher Dpi and lower image size and later reduce dpi for final output of 20 x 68.

Was I dreaming or is this true?

The main thing to be aware of is that file size has nothing to do with DPI, or printed image size. These are all concepts we create ourselves - they don't mean a great deal really. What makes up the image is pixels - and it is the overall number of pixels that affects the size of your file. If you scanned at a higher resolution, but a smaller dimensional size, it is true you can change the DPI in photoshop later, and thereby increase the 'print size'. But this really means nothing, and the file size will be identical to your original scan.

Sorry I'm not that great at explaining this - but as long as you understand that DPI is just a concept we use for our own convenience, and it is total pixels that is the real information. For instance sometimes I find it easier to scan a slide at 2000dpi. I don't bother adjusting it to 300dpi to print it - I just scale it in print preview to fit my page. The result is exactly the same.

Hi Wolfer, if I understand right, you have 2 pictures of 4"X6", and you want to produce a picture 20"x68".

OK, first of all, why do you need the final output to be at 400ppi, you should get a quite acceptable picture with a final output of 250ppi, this would give you a file size for your final picture of about 85M.

To get this, you would have to scan your original images at a resolution of about 1250ppi, giving two files about 37.5M in size.

There will probably be some overhead, created by your stitching software, so the 85M file will grow some, but it should give you more manageable file sizes.

Hope this helps.

Another thing to consider is that most plotters don't have a buffer than can handle a file that size, even 200dpi images at that size might cause it some problems.

Consider taking it to a photo shop and having it printed on a light writer. The laser exposing process gets excellent results at only 100-150dpi and can easily handle an image that size at 200dpi. I don't know about your area, but here it costs about $15 a square foot to print an image on a light writer and about $13 a square foot for a full color plotter print. In addition the light writer has much better color range and will print on actual photo paper.

Just another suggestion, but I get all of the displays where I work printed that way and they look much better.

Michael

The program I think you may be referring to is called Genuine Fractals.