Batch Enlarging JPEGS

Best way to maintain quality?

[stuart]

Hi all,
I'm sure i've seen a really good thread on this before, but after endless searching cannot find it.

I'm trying too batch enlarge by 50% a number of 320x240 pixel jpegs but maintain their quality as much as possible. They're already compressed for web (using fireworks) and it would help to work from the compressed copies, but i could get the originals together if needed.

Is there any software that would make a good job of this? I understand there's a loss of quality issue when enlarging jpegs but thought they're might be some genius software available.

TIA for any guidance.
stuart

[benihana]

firstly i would recommend getting the originals - its always worth avoiding recompressing if at all possible.

PhotoShop will let you create an action to do what you need and then run it agaisnt a batch, but you need to be aware that diffenert types of images (i.e. compositionally) can take different levels of compression, t some point you are going to have to sacrifice either file size or quality on some of the images.

[john316]

Fireworks and a few others have batch processing, look over the settings and go.

[Mardi_Gras]

i could get the originals together if needed.

By all means, get the originals. I would not waste time trying to enlarge web-optimized JPEGs by a factor of 50%.

Sorry there is no genius software available ;)

[edit_g]

enlarge by 50% a number of 320x240 pixel jpegs

I'm thinking that the loss of quality will be quite great.

If you have the originals (I'm assuming that they're larger size) you can use photoshop file/automate/fitimage and it will do it for you - you can also do this to make the images larger. I'm pretty sure you can batch this up - but I don't know how.

[Mardi_Gras]

My reference to no software meant no software that will enlarge a web-optimized image 50% without a pronounced loss of quality.

There are plenty of programs, including the aforementioned Photoshop, as well as Paint Shop Pro 8 (free beta available) that will handle batch processing.

But I don't think you will like the results...

[edit_g]

But I don't think you will like the results...

I can guarantee that you won't like the results...

It's a tough nut to crack - you won't have much luck at all if they're are detailed images.

Oh for vector graphics.

[martinibuster]

Fireworks does have a batch processing feature.

[korkus2000]

I think the concensus is to get the originals for your batch process. Most graphics programs can achieve this. If you don't have any of the ones mentioned you can go to download.com and search for batch process jpeg.

Trust everyone here that if you try and use the web optimized versions you will not be happy with the results.

[stuart]

Many thanks everyone, if anyone else stumple's across this thread for similar reasons here some related reading I found:

[webmasterworld.com...]

But just can't find that original thread and it was exactly what I wanted, been looking for weeks on and off, perhaps I dreamt it in hope!

Thanks again all.
stuart

[HughMungus]

I used to use a program called, "eyebatch" for this.

[waldemar]

For the quality: There is a software from Alien Skin called "Image Doctor" which received very good reviews for improving quality on web-compressed jpgs. Maybe it can help with your enlarged images...

[ctsolutions]

I don't think it does batch processing, but there's a program called Imagener which claims to enlarge images without quality loss - search and ye shall find. You must start with the originals, though, for heaven's sake.

There are also a number of other image enlarging programs that use some sort of fractal-related process. I don't know much about how it works, or whether any of them have batch processing available, but I imagine that the more expensive programs do. There is a plug-in for Photoshop called Genuine Fractals that I have heard produces excellent results, but I haven't tried it as it's a bit pricey for me and there's no free trial. If you do decide that you need it badly enough to pay for it, I'd love to hear your review. Again, use the originals.

For just a plain batch resizer I recommend MIR (multiple image resizer) if you have the .net framework installed.