Adding jpg artefacts to image on a layer...how ?

[envirog...@adobeforums.com]

Hi,
I have a low resolution image 'A' from someone that has been jpg'd, perhaps a few times. It has pixels that are visible without too much effort, and edges to objects that are not regularly stepped, say 3px wide then 1px down in places (lets call this vari-stepped). Studying the image, the pixels are in fact formed into blocks or squares of pixels. I think we all know what I am describing !

I now have taken into this image part of another far better image 'B' and need to make it look like it belongs there. Adjusting colours and focus and softening edges is one thing, but it needs that jpg artefacting adding. Simply dealing with the addition beforehand and lowering its resolution doesnt do it, as the resulting pixels are not blocky, edges are not vari-stepped. The jpg feel to it is not there.

What controls can I use to achieve this on the image in that layer after its brought in, with Photoshop CS2 or even P'shop 7 which I still use as I prefer layer links there ! By working in the image I can compare effects to the recipient image. Perhaps only the latest Pshop has what I need ?

Pixelate filter is not enough, its too crude, lowest setting is too much, it doesnt do the blocky look, or the vari-steps.

Getting a better image 'A' is not an option.

Wish List. It would be great to have an ability to tell P'shop to analyse the image 'A' and apply settings to make image 'B' the same.

Envirographics

[Phosąfour dots]

Heya, EnviroG...

I know it's a rare need, but I run across it as well, often enough that I've asked about it and requested it, too.

I've long wished for a filter that would allow me to add real JPEG artifacts as a filter, with the ability to adjust the compression with a slider and watch the changes in a preview.

I've looked around a few times, and haven't ever seen a 3rd-party filter that does it, so our only choice is to save out separate files with compression applied and composite them back into the original we're trying to match.

[J_Ma...@adobeforums.com]

Save B as a JPG?

[Phosąfour dots]

That's the only way, J, unless somebody has built a "JPEG Artifact Filter w/Built In Preview" that I've never been able to find.

The idea, for example, is to have a tore-up-with-JPEG-blockiness as a Background base image, and to be able to apply JPEG-style compression on a crispy clean object in Layer 1, and to be able to preview as you adjust the filter's compression slider so that Layer 1's crappy look matched the base image. You get it closely matched, and hit the "OK" button in the filter's dialogue box.

[Mathias_...@adobeforums.com]

Seeing that JPG compression compresses blocks of pixels 8x8 pixels large, you don't really need a preview. But you can't mimic other types of compression artifacts accurately, say using the Mosaic filter.