Re: NativeJpg now available at introductory price

Hi David,


While the Delphi 2007 test went OK, the Delphi 5 one produced some error
messages about missing components when I loaded the .DPR file, but it
seems to run OK.

Yes, the form contains autocheck menu items, which wasn't there in D5. I'll
probably update this so the project doesn't use the autocheck property.

Thanks, Nils. I'd buy NativeJpg like a shot, but I have some very large
JPEGs so I need to test to be sure that it can handle them. What is the
largest size tested?

Basically this depends on the memory you have available. NativeJpg has a
slightly different approach than the IJG library. It allocates space for all
the coefficients and samples, for the complete image, not just for e.g. a
16-row buffer.

Let's take an example of an RGB image, 3000x2000 pixels with standard YCbCr
encoding. The jpeg component holds the following chunks of mem:

- Coef Y: 3000x2000x2bytes = 12M bytes
- Coef Cb: 1500x1000x2bytes = 3M bytes
- Coef Cr: 1500x1000x2bytes = 3M bytes
- Sample Y: 3000x2000x1byte = 6M bytes
- Sample Cb: 1500x1000x1byte = 1.5M bytes
- Sample Cr: 1500x1000x1byte = 1.5M bytes
- Bitmap RGB: 3000x2000x3bytes = 18M bytes

So the largest chunk is really the bitmap. If you use extreme image sizes,
then just test the component with the trial version.

I took this approach because "memory is cheap" these days, it allows the
code to remain nicely modular. Also the chunks aren't allocated/deallocated
each time, they're kept over the life of the jpeg component, so are reused
when loading multiple images.

The other reason is that the lossless operations become very easy if all
coefficients are in memory.

Btw, I've only tested with practical images, ranging up to something like
6000x4000 at most. Feel free to test with larger ones :)

Nils



"David J Taylor" <david-taylor@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
schreef in bericht news:4728bf1e$1@xxxxxxxxxxxxxxxxxxxxxxxxx
Nils Haeck wrote:
Thanks, Nils, I guessed that might be the case.
How long is the opening offer open for?

Cheers,
David

It will be open indefinitely, but only though the link in the post. If
Google stores it, and SimDesign exists that long, that could be for
centuries :)

Nils

Thanks, Nils. I'd buy NativeJpg like a shot, but I have some very large
JPEGs so I need to test to be sure that it can handle them. What is the
largest size tested?

Cheers,
David



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