Increasing Image File Size

rob-nikon

rob-nikon

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Rob
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I need to increase one my image files from 1mB to over 8mB. I've previously heard about interpolating an image to increase its file size but I've never done it before. Would it be possible to interpolate a JPEG image so its over 8mB using Photoshop Elements 9?
 
Yes.. but it will contain no more detail than the 1MB file. You can't add what's not there.
 
If you do it in very small incriments you will probably double the pixel dimensions of the file without too much loss of detail but its time consuming, Genuine Fractals does a half decent job b ut some of its claims are hard to beleive.
 
Thanks for your help, I've had a try with elements and managed to get the file size to 8mB. I can understand that the detail won't be any better than the 1mB file. They want the file as a minimum of 8mB in jpeg form. If it wasn't for the fact I'm donating the fee to charity I would have given up a while ago.
 
Opened or unopened size?

A compressed, unopened 1Mb Jpeg may well be 8Mb when opened in Photoshop.

Alamy and their ilk (plus numerous graphic designers/mac desks) normally refer to size when opened.
 
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I've sent through the 1mB jpeg and they have come back to me requesting a jpeg file of a minimum size of 8mB. It's for Winterwatch on the BBC, I think i will wait to see what the answer is from my email and file transfer tomorrow.

How do you find out the file size once opened in photoshop elements?
 
It's in the file info pain, bottom left, depending on what you have it set to display.
 
Gary Coyle said:
If you do it in very small incriments you will probably double the pixel dimensions of the file without too much loss of detail but its time consuming, Genuine Fractals does a half decent job b ut some of its claims are hard to beleive.
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+1 is the way to go to increase an image size...
 
Is there a bigger copy - perhaps the unedited original - lurking in a forgotten corner of your hard drive?
 
I forgot to add - the requesters are probably under the impression that you have reduced your image size down to 1MB from an originally bigger file (surely you have?), therefore they are looking for the high-resolution version. I would expect you do have a high resolution version (the one that came straight out of the camera) somewhere which would be closer to, or over, 8MB.
 
Gary Coyle said:
If you do it in very small incriments you will probably double the pixel dimensions of the file without too much loss of detail but its time consuming, Genuine Fractals does a half decent job b ut some of its claims are hard to beleive.
Click to expand...

No

If you increase in small increments, instead of by an integer multiple of Pixels, the filter used to interpolate will be more complicated and will lead to more ringing, aliasing and noise.
 
alanmossdan said:
Yes, increasing the file size will not add any more detail. If you imagine a 10x10 array of pixels all of different colours to be your original - you would have 100 different pixels and colours. You can increase the file size by about 10 times by making it a 100x100 array. However, your software still only has the original 100 pixels to play with so it merely enlarges each of your original pixels (1x1) and stretches it over 10x10 pixels, so you would still only see 100 colour that look like 'big pixels'.
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No it doesn't. No filters work like that.
 
st599 said:
No

If you increase in small increments, instead of by an integer multiple of Pixels, the filter used to interpolate will be more complicated and will lead to more ringing, aliasing and noise.
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Not so in my experience or the experience of advertisers and picture software experts who have up scaled my bog standard 12mp images big enough to stretch across a 40ft x 9ft dressing room wall and they even cropped it beforehand and have even upscaled a 2100x1500 pixel image across the full width of a bus.
 
Gary Coyle said:
Not so in my experience or the experience of advertisers and picture software experts who have up scaled my bog standard 12mp images big enough to stretch across a 40ft x 9ft dressing room wall and they even cropped it beforehand and have even upscaled a 2100x1500 pixel image across the full width of a bus.
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And those who have actually compared upscaling in increments with doing it in one big jump have found - b****r all difference. LINK
 
hollis_f said:
And those who have actually compared upscaling in increments with doing it in one big jump have found - b****r all difference. LINK
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Well i can clearly see a difference in the 2 100% crops and in favour of the gradual upscaled version, its not a big difference but it is clearly visible
 
Having said what i have done i would imagine in the real world when viewing the final output image using either method would make it almost impossible to tell the difference if at all, its not as if we view these upscaled images close enough to be able to nit pick

i think the author of the article may have hit on something when he says the latest software ie CS5 handles upscaling much better than its predecessors.
 
hollis_f said:
And those who have actually compared upscaling in increments with doing it in one big jump have found - b****r all difference. LINK
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Conclusions?It is hard to observe a significant difference between the two, although there certainly is sone(sic) (as is shown by the layer subtraction result). If anything, it appears that there could be slightly better reproduction of detail in the direct upsizing method.
 
I find it a little odd that they have asked for a particular file size, as the size of a jpeg is highly dependant on it's content and the jpeg quality it was saved with.

Are you sure they didn't mean to ask for an 8MP image rather than an 8MB image??
 
PistolPeteUK said:
I find it a little odd that they have asked for a particular file size, as the size of a jpeg is highly dependant on it's content and the jpeg quality it was saved with.

Are you sure they didn't mean to ask for an 8MP image rather than an 8MB image??
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Nope. The number of pixels has little bearing (apart from the obvious) as an indicator of file/image quality. The answer is actually in your comment... the lower the file size, generally the lower the quality.


From Alamy's guide to file size:

Jpeg is a compressed file format. The compressed file size (size on disk) varies with picture content and should generally be ignored, as long as it’s no bigger than 25MB, which is our upper limit for Jpeg size. What’s important is the uncompressed (opened) file size. The opened file must be at least 24MB at 8 bit to get through our quality control. Typically a 24MB 8 bit Tiff file will be between 2MB and 5MB as a Jpeg if your image was shot digitally. Film scans will be larger. This is because Jpeg “sees” film grain as image detail and compresses it too. Remember, we do not want a Jpeg 24MB in size as that would be ridiculously large when uncompressed (opened)!
One thing you don’t want to do is work on your images whilst they are in Jpeg form, repeatedly saving as you go along. Saving a Jpeg as a Jpeg is pretty much a no no, as you are recompressing an already compressed file.
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Nahh, I suspect Pete's right. I am betting they're looking for a higher resolution version of the image, not an up-scaled version of the image. If they want to up-scale it, they could do that themselves and I think they'd have done it rather than ask the OP to do it.

There's a reason to go back to the author and ask for a larger file, and for them to up-scale a low resolution image isn't that reason.
 
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