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OptiPNG file type plugin (November 30, 2008)

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Fixed :)

Wow, that was fast. Thank you very much, I l-o-v-e this plugin and use it very often.

Edit: Could you just attach the zip to your first post? I had several times trouble with media fire (cookies enabled, it's their fault) and now again I couldn't download...

Agreed. Mediafire doesn't like my computer, either.

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Erm, I don't know how important this actually is, but I scan my drawings with 300 dpi and when I save them with optimized png, the dpi value is taken down to 96 dpi. The same issue occurs when using irfan view with pngout. I don't know if this has any impact on quality, but it is important for me to save the pictures in the same (or better :) ) quality they had when I scanned them, and so I want to ask if a dpi setting could be added to the plugin's options in the case that lower dpi values affect the quality negative. I know that 72/96 dpi are good for viewing, but I maybe want to print the pictures again and also I just don't want to loose quality.

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It's probably just discarding the DPI information stored in the image. As long as the pixel resolution is the same (which it is), there is no change in quality of the image.

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It's probably just discarding the DPI information stored in the image. As long as the pixel resolution is the same (which it is), there is no change in quality of the image.

Ah, that sounds OK.

Someone please correct me if I'm wrong - but I think I'm not ;) - but there will be no change in quality when viewing (screen); when printing, the lower the DPI the lower the quality...

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DPI is dependent entirely on the inch size the image is stretched to fit. So no, it won't show any difference; if you printed it at 72DPI or 300DPI in precisely the same area on a page, both will look exactly the same. Setting an image to 300DPI is a trick we use to make it look on a computer screen the way it would look on a piece of paper. If you send it to the printer with the same final size, there's no change in quality.

Think of it this way: The image has a certain resolution, and that's it. It can't get any better, but it also can't get any worse unless you size it up.

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...So no, it won't show any difference; if you printed it at 72DPI or 300DPI...

...Setting an image to 300DPI is a trick we use to make it look on a computer screen the way it would look on a piece of paper. If you send it to the printer with the same final size, there's no change in quality.

Think of it this way: The image has a certain resolution, and that's it. It can't get any better, but it also can't get any worse unless you size it up.

Sorry david, but I think this is a little bit inaccurate. From Wikipedia:

DPI in digital image files

DPI refers to the physical size of an image when it is reproduced as a real physical entity, for example printed onto paper, or displayed on a monitor. A digitally stored image has no inherent physical dimensions, measured in inches or centimeters. Some digital file formats record a DPI value, which is to be used when printing the image. This number lets the printer know the intended size of the image, or in the case of scanned images, the size of the original scanned object. For example, a bitmap image may measure 1000×1000 pixels, a resolution of one megapixel. If it is labeled as 250 DPI, that is an instruction to the printer to print it at a size of 4×4 inches. Changing the DPI to 100 in an image editing program would tell the printer to print it at a size of 10×10 inches. However, changing the DPI value would not change the size of the image in pixels which would still be 1000×1000. An image may also be resampled to change the number of pixels and therefore the size or resolution of the image, but this is quite different from simply setting a new DPI for the file.

Edit (to further clarify):

This way (as stated), DPI in an image is the way a printer gets informed of the size of the printing (behind the scenes).

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Yes, when the image is printed at its native resolution. But that's sometimes not done; for instance, in Adobe programs, you can resize the image to fit the printed page even if its DPI makes it much larger or smaller.

In essence, DPI tells the printer what size the image would like to be printed at, but the program you're printing from can change that at will, and often does.

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Ok, that's enough discussion about DPI. The bottom line is that OptiPNG discards DPI information (hey, its taking up space) and that this does not change the actual pixels.

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...DPI tells the printer what size the image would like to be printed at, but the program you're printing from can change that at will, and often does.

Ditto!! 8)

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Thank you so much! :D I've been looking for a PNG optimizer for so long and so many of them suck, do not work, freeze, are full of spyware, cost money, and all kinds of stuff you wouldn't want. One of the optimizer optimized a 32kb picture down to 29, but yours got it down to 20.

Once again, thank you! This will really help me decrease the file size of the new iSafari that's coming out.

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Update:


  • [*:1z78ct83]Grayscale was lossy due to mathematical inaccuracies.
    [*:1z78ct83]Replaced preview with an option to skip optimizing
    [*:1z78ct83]UI reorganization

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Sweet! Thanks. The Skip Optimization thing is something I was hoping for, but didn't want to ask for. I LOVE this filetype, and use it 97% of the time I work with Paint.NET.

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I just tried using this, and it seems to not be working for me...

  • [*:345mrtcv]One multi-layered image
    [*:345mrtcv]Flattened
    [*:345mrtcv]Saved as normal PNG (for comparison)
    [*:345mrtcv]Re-opened .pdn
    [*:345mrtcv]Flattened
    [*:345mrtcv]Saved as Optimized PNG - default settings
    [*:345mrtcv]Closed

Now, if I try to reopen the Optimized PNG, it says: 'There was an error opening the file.'

If you look at the image thumb in Windows Explorer, there is no preview, and the file size is 0 bytes.

Help?

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Eh? No, it didn't. Maybe it was just too fast for it to draw...

It always came up when I used it. Especially on the larger images.

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Eh? No, it didn't. Maybe it was just too fast for it to draw...

It always came up when I used it. Especially on the larger images.

Wasn't there a checkbox "show optimization process"? I hadn't it enabled, maybe you had.

I have the old version, I will have a look.

EDIT: To make it clear, I use the current version, but have a backup of the former one.

Looks like it's that checkbox what I want.

Edit 2:

Here are screenshots:

This is how it looks now:

nowje7.png

This is the older version:

pastnq0.png

In my opinion, the fromer UI is much better.

Edit 3: Erm... If you use the "optimized png" file type output instead of the normal png entry, it is rather clear that you want optimization. So why is there a checkbox "Optimize"?

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