Photoshop: Save For Web function with new faulty resolution defaults

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  • Updated 4 years ago
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Today, for the first time in 15 years, I found that the Save For Web function is now changing the resolution of the image being saved to default ppi settings based on the quality settings of Low, Medium, High, Very High and Maximum. That means that if you want to save your image at a Maximum Quality, you are not able to save it at the World Wide Web image standard of 72 ppi. In essence, this issue makes the Save For Web function obsolete because an image set at Maximum will have a 300 ppi resolution and will appear much smaller on the web verses their apparent size at 72 ppi with the same pixel dimensions. While image resolution standards are changing for online applications, I HIGHLY recommend that this new resolution spectrum be returned to its original function of maintaining the base resolution of the source image being Saved For Web. This will allow the user to output the image for whatever application required.
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Marguerite Lena

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Posted 4 years ago

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Chris Cox

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Um, no - SFW doesn't change ppi settings at all, and certainly not based on JPEG quality. And image browsers ignore ppi values anyway - they just use the raw pixel sizes.

What other application are you reading the ppi values in?
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Marguerite Lena

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While I would agree with you yesterday, today is another matter. When I open the image that was Saved for Web in Photoshop, the resolution shows 300 ppi instead of the 72 ppi in the source image. The 72 ppi is confirmed in Bridge. I should also mention that I am on a Mac and these kind of glitches seem to crop up more on Macs. I had a similar experience this last summer, but it went away after a week.
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Chris Cox

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The SFW code hasn't changed, and the file saving code doesn't differ between platforms.
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Marguerite Lena

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While browsers may ignore the ppi values, the increased file size of a 300 ppi image vs. a 72 ppi image with the same pixel dimensions can add wait time to the image's appearance online.
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Chris Cox

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If you maintain the same number of pixels - then there would be zero difference to the browser. Again, browsers ignore the resolution values.

If you resample the image to increase the number of pixels - then of course it would take longer to download and display.
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Marguerite Lena

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Do you mean to say that browsers see 2 images with the same pixel dimensions, but with one at a resolution of 72 ppi and the other with a 300 ppi resolution, as having the same file size? The last save I made to my computer showed a file size of 2.8 MBs for the higher resolution versus .98 MBs for the smaller resolution.
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Chris Cox

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Yes, if they have the same pixel count, then they must be the same file size. The resolution metadata does not change the pixel count or the size of the files (unless you're talking printed size).

If the file sizes differ, then the pixel counts differ (and you made a mistake).
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Marguerite Lena

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I don't normally download my images once I have uploaded them online, but I certainly could do that and confirm that the file sizes are the same from 2 images that were uploaded with different resolutions. Otherwise, yes, what is saved to a PC drive would be the "printed version" if it has a resolution of 300 ppi and therefore it would have a larger file size. That stills does not explain why both an Adobe technician and I discovered today that the SFW is now changing the resolution settings based on the quality setting. In fact, he helped me write the Problem notice. This is happening in Photoshop CC and Photoshop 2014.
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Chris Cox

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I have no idea how someone on tech support could make that mistake. But the resolution of the image is not related in any way to the JPEG quality setting.