[Newbies] Reading PNG images into squeak image is slow

[Levente Uzonyi]

On Tue, 22 Oct 2013, Levente Uzonyi wrote:

> On Tue, 22 Oct 2013, Mateusz Grotek wrote:
>
>> It is (even on Cog).
>> What is the reason for that?
>> Is it a problem with the algorithm used in the image or it's unsolvable
>> inside the image and a plugin or FFI is needed.
>
> I doubt it can be significantly faster using smalltalk only. When we wanted 
> to store images in files using lossless compression, we decided to use jpeg 
> instead of png, because it has plugin support, so it's a lot faster to load 
> and save the images.
>
>> 
>> P.S.
>> 
>> Code:
>> (PNGReadWriter formFromFileNamed: something) durationToRun "0:00:01:09.591"
>> "unacceptale if you want to program an image browser"
>> 
>> Data:
>> 1301.png: PNG image data, 2048 x 1536, 8-bit/color RGB, non-interlaced
>> (a pic of a street taken from a cell phone)
>
> That image is huge. Cell phones and digital cameras usually create jpeg 
> images. But if you really need to support png, then ffi or a plugin is the 
> way to go.

I just realized that it's one minute and nine seconds runtime for you. 
That's way more than what it should be. Reading an 1920x1004 
non-interlaced RGBA png image takes less than 200 milliseconds for me 
using Cog.

Can you share the png image, so we can test it?


Levente

>
>
> Levente
>
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