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Photoshop JPG quality - HE..ELP! (1 Viewer)

I have been a user of PhotoImpact from Ulead for several years, progressing from v4 to XL. However, for various reasons I have decided to switch to Photoshop Elements v3 from Adobe. I am therefore experiencing the normal conversion problems when things that I can do easily with PhotoImpact, because I'm familiar with that product, appear difficult with Photoshop!

Most such problems are easily fixable, but one problem I have found impossible to get around. It appears to me that Photoshop cannot write JPG files with a similar quality/size trade off as that achieved by other software.

I run i-Catcher software to collect images from a couple of bird boxes in the garden. This produces images of 384x288 pixels from video cameras either inside or just outside the nestboxes. I use 24-bit colour and so the uncompressed size of these images is about 324KB. These images are converted to JPG files of about 26KB by selecting quality of 75% in the i-Catcher software.

If I load one of these image files into PhotoImpact, and copy it with no modification by immediately using Save As, with JPG quality set at 80, then PhotoImpact also writes a file of about 26KB of a quality that is indistinguishable from the i-Catcher image, even at high magnification.

However, if I do the same thing with Photoshop and I choose Medium quality (6), I end up with an image of similar quality but much larger, about 50KB for the above example. If I want to get a file of similar size, I have to specify ultra low quality (0) and this looks much worse.

The size of these images is important as the good ones end up on our web site at www.biggonline.co.uk

So that you can see what I am talking about, I have attached three images. The first, Bluey.jpg - 26KB, is the original image produced by i-Catcher. The second, Bluey-PI.jpg - 26KB, is the image created by opening the first using PhotoImpact XL, and creating a new image using Save As, with a quality setting of 80. The third, Bluey-0.jpg - 32KB, is the image created by doing the same with Photoshop Elements v3, using a quality setting of 0 (zero).

Not only is this a much poorer image, which you can clearly see if you zoom in to 400% or so, but it is also more than 15% larger!

I find it difficult to believe that it is Adobe that has got it wrong, I realise it's probably me! What am I missing?
 

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BrianB said:
Hi Ornithopod

My first question would be if it works best in PhotoImpact why use Photoshop, but I do agree that it's strange. It's difficult to see what's happening without seeing the original uncompressed image.

Hello Brian,

As I said in my PM, I cannot send you the original uncompressed image because there isn't one! The best I can do is the one I have posted called Bluey.jpg as this is the output I receive from the i-Catcher software.

There are many other reasons to switch from PhotoImpact to Photoshop - unfortunately, I assumed that these days writing JPG files was easy and did not investigate this before deciding to buy!!

Malcolm
 
BrianB said:
Hi Ornithopod

Further to my PM here are the images I saved through Photoshop's "Save for the Web" option. I don't know if this is available in Elements but if it is, give it a try. They were done using the high, medium and low settings for JPEGs. The sizes for the lower two are good, though the quality on the lowest is below average.

Hi Brian,

Elements 3 does have the "Save for Web" option - which I am rapidly coming to think is just as well! All three, even the lowest quality image occupying only 12KB are of substantially better quality than the 32KB image, posted as Bluey-0.jpg in my initial post, produced by "Save As". Why this should be so escapes me. Just as confusing is why all JPG images produced by "Save As" turn out to be about 15KB bigger than they are reported to be in the JPEG options window!

Of your three images, I feel that the high quality image at 33KB is indistinguishable from the original. The medium quality image at 21KB is almost as good, but I feel that I can see a small loss of quality. However, it is about 20% smaller than the original.

With the low quality image there is a definite increase in pixellation, but even this, which is 12KB, looks significantly better than the smallest low quality image created by the "Save As" facility which is 32KB!

I have recreated the medium quality image on my PC using the "Save to Web" mechanism and have reproduced your results so it isn't some hidden difference between Photoshop and Photoshop Elements put in to make us buy the real thing!

Someone has suggested I ask Photoshop Tech Support for the reason for the difference, so I might try to find who to address the question to!

Thanks again for your help.

Malcolm
 
ornithopod said:
Of your three images, I feel that the high quality image at 33KB is indistinguishable from the original. The medium quality image at 21KB is almost as good, but I feel that I can see a small loss of quality. However, it is about 20% smaller than the original.

Malcolm

Malcolm,
Don't forget, if you open a jpg and then resave it, you will automatically incur a small quality degredation just by doing that, no matter what quality setting you pick, since saving a jpg ALWAYS loses quality everytime you do it.

If you want to determine what is the best setting to use with Elements, you should start with an uncompressed image (e.g. a bmp), or a lossless compressed image (e.g. a tif). Save it as a jpg at different quality levels and then compare the results to the original.

To follow this scenario with images from digital cameras, the first thing you should do is open a jpg from a camera and save it as a bmp or tif. Then use that bmp or tif for manipulation.

If you already know all this, I appologize. Going back to your original question, I agree that it is VERY strange that Elements' Save As produces such terrible quality vs its Save for the Web. Have you checked to see if there are "advanced" options? For example, Paint Shop Pro offers several types of jpg compression in an options dialog. Perhaps the Save As uses a different jpg compression algorithm than the Save for the Web.
 
RAH said:
Malcolm,
If you want to determine what is the best setting to use with Elements, you should start with an uncompressed image (e.g. a bmp), or a lossless compressed image (e.g. a tif). Save it as a jpg at different quality levels and then compare the results to the original.

Hi RAH,
I have now done this with a uncompressed BMP picture and reproduced the same effects. There are two issues. 1. Why are the images 12-15K larger than reported by the JPEG Options box? 2. Why is the quality produced by the "Save As" dialog worse than that of the "Save for Web" dialog?

Unfortunately, as ADOBE PROVIDE NO FREE SUPPORT for their products, not even email support, I can't ask them!


RAH said:
Going back to your original question, I agree that it is VERY strange that Elements' Save As produces such terrible quality vs its Save for the Web. Have you checked to see if there are "advanced" options? For example, Paint Shop Pro offers several types of jpg compression in an options dialog. Perhaps the Save As uses a different jpg compression algorithm than the Save for the Web.

There are three JPG options, Baseline Standard, Baseline Optimised and Progressive, but they don't appear to be much different.

However, thanks to BrianB I am now aware that "Save for Web" is OK!

Thanks again BrianB

Malcolm
 
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