| Re: Incomplete ouput PNG files. [message #78691 is a reply to message #78686] |
Thu, 15 December 2011 09:19   |
penteado
Messages: 866
Registered: February 2018
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Senior Member
Administrator |
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On Dec 15, 12:23 pm, David Fanning <n...@dfanning.com> wrote:
> alx writes:
>> I agree. RESOLUTION keyword is a solution, but the (true or implicit)
>> window size also plays some role. For an original image of size
>> 2224x1124 and PNG output(from p=image(DIMENSIONS=...) &
>> p.save,BUFFER=...,RESOLUTION=...), I find:
>> BUFFER=1, RESOLUTION=96, DIMENSIONS=[800,600] -> FILE SIZE = 99 kB
>> BUFFER=1, RESOLUTION=300, DIMENSIONS=[800,600] -> FILE_SIZE = 290
>> kB
>> BUFFER=1, RESOLUTION=600, DIMENSIONS=[800,600] -> FILE SIZE = 488
>> kB
>> BUFFER=1, RESOLUTION=600, DIMENSIONS=[640,512] -> FILE SIZE = 423
>> kB
>> BUFFER=1, RESOLUTION=600, DIMENSIONS=[1024,768] -> FILE_SIZE = 602
>> kB
>> BUFFER=0, RESOLUTION=600, DIMENSIONS=[640,512] -> FILE SIZE = 423
>> kB
>> BUFFER=0, RESOLUTION=600, DIMENSIONS=[800,600] -> FILE SIZE = 408
>> kB
>> BUFFER=0, RESOLUTION=600, DIMENSIONS=[1024,768] -> FILE_SIZE = 602
>> kB
>> Note the (strange ?) difference between BUFFER=0 and 1 for
>> DIMENSIONS=[800,600]
>
> Yes, I'm confused about just what "resolution" means in
> this context. Even more confusing is why Coyote Graphics
> files seem to be smaller in overall file size, while
> consistently larger in image dimensions. I'm guessing
> "resolution" must be one of those things that is in the
> eye of the beholder. :-)
Maybe such a comparison should be done in terms of pixel size, not
file size, since PNG has compression, thus making the file size not
proportional to the pixel size. Also, different filtering and
interlacing options may change the compression ratio.
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