Support » Plugin: Imsanity » “File size of resized image was larger than the original”

  • Resolved joycegrace

    (@joycegrace)


    Hi, what does this error mean?

    “File size of resized image was larger than the original”

    I saw this post https://wordpress.org/support/topic/error-with-imsanity/ but I’m unclear:

    Does this leave the image untouched because it would make a bigger file size? Or does it go ahead and process the image but return an error that needs fixing on our end?

    Is there a way to resize images without creating the extra artifacts?

    Why is compression harder if we use Imsanity to resize? How can we fix this problem for the images that do get processed through Imsanity, if using an image compression plugin or something like that?

    Also, we got this error on an image that is 5304 pixels wide and 150 dpi, after setting the resize value to a max of 1920 and 90 dpi. Why would it say the resized image is larger?

    • This topic was modified 2 months ago by joycegrace.
Viewing 6 replies - 1 through 6 (of 6 total)
  • Plugin Author nosilver4u

    (@nosilver4u)

    “Does this leave the image untouched because it would make a bigger file size?”
    Yes, that’s exactly what it does 🙂

    If you got that while resizing from 5304 to 1920, that’s very unusual. But there are two reasons I can think of:
    1. The image is in the PNG format, and perhaps ought to be converted to JPG.
    2. The JPG quality is set too high. If I’m reading that right, you have the quality set to 90. Note that quality does not equal DPI, and DPI has nothing to do with displaying images on the web, it’s only relevant for printing images.
    So, drop the quality to 85 or 82 and see what happens. Also make sure nothing else is setting the quality even higher, because quality 90 doesn’t seem high enough to cause trouble…but it could.

    Thread Starter joycegrace

    (@joycegrace)

    Hello, thank you for the quick reply.

    Yes it was a png. However, these are the settings I used: https://cloudup.com/ciyBrIEOmeg

    I set it to convert PNGs to JPGs

    I didn’t know that DPI was different than quality. I meant that in the settings, I set what I thought was dpi to 90. Actually I was wrong, it was 82.

    With this further information, can you help us understand what we need to fix now?

    Can you help us answer the other questions?

    Thread Starter joycegrace

    (@joycegrace)

    Oh sorry I see the conversion can’t apply retroactively. But can you answer to the rest?

    Also, What can we do to see if we are setting quality higher? Does this imply we need to do a manual fix?

    • This reply was modified 2 months ago by joycegrace.
    Plugin Author nosilver4u

    (@nosilver4u)

    Indeed, if the image is in the PNG format, converting retroactively is a little risky. It’s something I’ve only implemented in our other plugin, EWWW Image Optimizer.

    I wouldn’t worry too much about the quality unless you are seeing problems with other JPG images. Like I said, 90 seemed low enough not to cause trouble, so I think you’re probably okay. That said, if you do install EWWW IO, we can take a look at the debug information on there and it’ll tell us what the “effective” quality level is after all filters are applied.
    If it *were* higher somehow, then you’d usually just go hunting for quality settings in other plugins (or your theme).

    Thread Starter joycegrace

    (@joycegrace)

    I asked about quality because you said, “Also make sure nothing else is setting the quality even higher, because quality 90 doesn’t seem high enough to cause trouble…but it could.” So I’m wondering what falls under “nothing else” setting the “quality even higher.” What would I need to check, apart from the settings in your plugin?

    Can you also help us with an answer to the other questions in my original post?

    “Is there a way to resize images without creating the extra artifacts?”

    Why is compression harder if we use Imsanity to resize? How can we fix this problem for the images that do get processed through Imsanity, if using an image compression plugin or something like that?

    Also, can you explain how we got this error on an image that is 5304 pixels wide and 150 dpi, after setting the resize value to a max of 1920 and 90 dpi. Why would it say the resized image is larger?

    The quality was set to 82 and I gave a screenshot of other settings above.

    Thank you

    Plugin Author nosilver4u

    (@nosilver4u)

    I don’t really know of any other way to check if something else is changing the quality without running the debugger from the EWWW Image Optimizer plugin. You would have to check every setting of every plugin that does anything remotely image-related, and all the settings for your theme. And even then, it’s feasible one of them could change the quality without allowing configuration. That wouldn’t be very nice, but it’s possible.

    “Is there a way to resize images without creating extra artifacts?” No, you can’t completely get rid of artifacts, that’s just a natural by-product of the down-sampling. You can possibly reduce them in a couple ways:
    1. Increase the JPG quality level.
    2. Make sure your server has the Imagick extension available (which is usually a little better than the GD extension used by default). You can check this under Tools->Site Health->Information->Media Handling

    “Why is compression harder if we use Imsanity to resize?” — I’m not sure I understand what you mean there? Do you mean that you get worse results from your image optimization plugin after an image has been resized by Imsanity? If so, that’s pretty natural, since we’ve just chopped out a lot of the room for compression by scaling the image down AND if you’ve left the quality level at 82, the image will potentially be better compressed than the original you uploaded.
    Overall, you’ll have achieved a lot more savings, but often the greater portion of the reduction is done by Imsanity when you scale images down.

    Regarding the 5304px image, you said it was a PNG, and that is pretty much the reason, but I’ll try to explain why. The PNG image format is lossless, and stinks really bad for photographic content. It excels in images with a very minimal number of colors. When you scale an image down, you add more colors because neighboring pixels get merged/blended together in the process. More colors = worse compression for any format (this is where some artifacts come from), but it’s dramatically worse for the PNG format, to the extent that even a 1000px PNG might be larger than the 5304 version.

    Let me know if I missed anything else!

Viewing 6 replies - 1 through 6 (of 6 total)
  • You must be logged in to reply to this topic.