batch processing

[OceanRider]

hi all, giving batch processing a try in PS elements. One question: (Well maybe two)

All I did was save a test folder ( 3 pics) at hightest j-peg quality and 300 dpi. The size in inches BEFORE processing was 48.66 X 32.44 in (thats 3504x2335Pixles)

AFTER converting all pics to 300 dpi, the size in inches changed to 11.68 x7.78 in . (pixels stay the same) Is this normal? What does this mean? Did I now loose blow up potential?

I am confused.

[Wendy Lilygreen]

Hi,
I just resized doing it that way and the image size stayed the same but the pixel count went up to 12800 x 8533. The file size went up to 312.5m the picture size stayed the same.
The original was 3072 x 2048 and 18M. Size 42.667 x 28.444in.
I don't know if this is normal or not.
The way I resize every thing is to crop it to say 12x8 at 300dpi I don't have to think too hard then!
Sorry I couldn't be of more help.

Wendy

[OceanRider]

Thanks. I do it that way too but if I have 300 wedding photos to do I might want to batch them all to 300dpi instead of one at a time.

[nitsch]

Oceanrider, thats because your original .jpg was saved at 72dpi. If you haven't resampled the image during this process (ie. changed its size in terms of actual number of pixels) then you have not lost any blow up potential you have merely changed the dpi from 72 to 300 which has had a corresponding effect on the relative print size at that resolution in inches.

[OceanRider]

Oceanrider, thats because your original .jpg was saved at 72dpi. If you haven't resampled the image during this process (ie. changed its size in terms of actual number of pixels) then you have not lost any blow up potential you have merely changed the dpi from 72 to 300 .


Sounds good.... but what exactly does this mean? >>>>which has had a corresponding effect on the relative print size at that resolution in inches<<<<

What is the difference if my pic was 48 in or smaller as in the newly dpi'd image? What does this do or not do. What does it mean?

[nitsch]

LOL I probably didn't phrase it very well. Lets try again! It makes absolutely no difference to the image itself.
Lets round the figures up to make it simpler. Say you've got an image which is 3000 pixels wide.
At 100 dpi your image 'size' will show as 30 inches.
At 300 dpi your image 'size' will show as 10 inches.

The 'size' which Photoshop reports in inches has decreased relative to the increase in dpi, but, the important point is it is still exactly the same image.

Does this help or have I made matters worse?

Nick

[OceanRider]

yes this help greatly, thanks a million. Still hard to wrap my mind around however!! lol ...

so by batch processing 300 images to 300 dpi to be printed at photo center, I loose nothing in future blow ups by going to 300 dpi and having image "inches" change. But what exaclty are these "inches" in PS? Does this measurment mean nothing or is there some use?

[nitsch]

I prefer to think of this measurement merely as an indication of the print size at the current resolution. The key point to remember is that as long as you don't resample the image you can set the dpi/inches to anything you want and it will not change the image at all.