Upres a JPEG vs a RAW or TIFF

[reneeroquet]

I need to print some horizontal jpgs in a large 24"x15" format and will need to upres them. Is it pointless to upres a jpg rather than a tiff or raw format? Sadly, I don't have access to the tiffs or raws. (I have requested them but so far the photographer has been unable to locate the originals. Big bummer. Designing a wedding album.)

Their current size is approximately:

Pixel Dimensions: 28.4 M
Width: 3861 pixels
Height 2574 pixels

Document Size:
Width: 16.087 inches
Height 10.725 inches
Resolution 240 pixels/inch

Thanks in advance!

[PeterAit]

Try it and see for yourself.

[Bart_van_der_Wolf]

I need to print some horizontal jpgs in a large 24"x15" format and will need to upres them. Is it pointless to upres a jpg rather than a tiff or raw format?

Hi,

It depends on the quality of the JPEG. It is a lossy compression format, and at the lower quality settings there will be visible artifacts, especially when enlarged. The JPEG artifacts may be covered up somewhat with proper tools (Topaz DeJPEG) and then upsampling with the proper tools, e.g. Photozoom Pro, may help in avoiding the most likely issues. But it is generally preferred to start with a better image quality.

Cheers,
Bart

[Mark D Segal]

I agree with Peter - try it and see - first without upsampling, then letting Photoshop upsample to a minimum of 180 PPI. Right now, without upsampling your file will deliver 160 PPI at 24 inches on the large dimension, which is normally too low for satisfactory print quality. Even at 180 it won't be great, but a photo that size would normally not be viewed very close up, so a few sins can be tolerated. The only way to know for sure is trying, and judge at normal viewing distance for that size photo.

[reneeroquet]

Thank you all, the photos will be 12x15, full bleed in a photo album. Will see how a test print turns out from the printer/bookbinder!

[sniper]

We often upres customers jpegs, as others have said theres a lot of variables, camera and lens quality for a start, then how the jpeg has been produced, compression, lots of editing etc, all affect final quality.
Your biggest problem might be customer expectation.

[eliedinur]

Thank you all, the photos will be 12x15, full bleed in a photo album. Will see how a test print turns out from the printer/bookbinder!

That makes a considerable difference from what you wrote earlier. First, the images will have to be cropped to 2574x3217 pixels in order to fit that aspect ratio. It is strongly recommended that you do the cropping yourself rather than letting someone else decide what stays in and what is thrown out. Second, that means an input ppi of 214 which will probably make for a reasonably good print.

Also, regarding the numbers that you posted earlier:
"Pixel Dimensions: 28.4 M
 Width: 3861 pixels
 Height 2574 pixels"
The number 28.4 M(B) is the image's file size before jpg compression. By comparing it to the size of the jpg in MB, you can get a rough idea of how much compression was done. A jpg that is 4 or 5 MB or more would not have received much compression.

[reneeroquet]

Thank you so much elied, lots of great information there.

I do apologize for my inconsistencies! I originally used the example formant of 24x15 inches. The book will have both 24x15 single image layouts, as well as 12x15 single image layouts.

[LesPalenik]

If your JPG files were saved with a strong compression, you might be able to improve them somewhat by running them first through Topaz DeJpg plugin.

[reneeroquet]

They are all about 1-2 MB. I am practically begging the photographer to search a little harder for the original job/tiff files...