Matching Jpeg Artifacts and Pixelation – not removal – How to?

[Keith Carmichael]

My first piece of advice would definitely have been to save the fruit and bottle at the lowest JPEG setting–you can also experiment with some of the other compression modes in the “Save for Web and Devices” dialogue. But, different images (and sizes of images) will acquire different artifacts upon compression.

Other things that you can try:

-Playing with the levels–I suspect the real reason why your images are standing out is because they are crisper and seem to have more contrast. Tweak the levels to wash them out a little more.
-Adding noise (filters>noise>add noise)
-Make sure the mask around your images is appropriately soft (so they don’t have a crisp line around them.)

Here’s what I would do for light angles.

-First: can I ignore them? Movie posters are full of mismatched light angles that no one ever notices.
-Second: Can I flip one of the images to better approximate the desired angle?
-If those fail, I like the Dodge tool to add highlights. Dodging Highlights produces a bright highlight (like hair or metal would have,) Dodging Midtones produces a less saturated highlight. To add shadows, you can use the Burn tool, or create a new layer with the blend mode set to Multiply and just paint some shadows on. Just choose the most obvious aspect of the lighting scheme and add a highlight or shadow or two to match–don’t focus on reversing it completely.

And of course, you’ll need new shadows for the objects you’re adding (and/or reflections, if the table is shiny.)

[Marc Nibor]

Thank you very much Emily for this detailed answer.

I came close with the artifacts… but just resaving was not enough. I actually ended up to size down (transform) and size up the fruits over and over until the quality was matching.

As for the levels… changing the levels alone was not enough. after trying out alot of other things I found that changing the vibrance worked best.

I did not get any satisfying results with the lightangles yet, so I will try out all your suggestions asap –

again…. thank you very much for your effort.

Marc

[Nikita Zhekova]

I have a photo whose background needed blurring out, to simulate shallower depth of field. compared to adjacent areas unblurred, the blurred area was far too smooth. the rest of the photo contains pixelation as per jpeg lossy compression.
filter -> noise -> add noise didn’t do the needed job of matching the two adjacent areas. the speckles were a good start, but were too small. altering their percentage, the only available option, didn’t help.

However if you go to filters -> artistic -> paint daubs
and use a wide blurry brush,

adjusting the size of the texture to match the other areas of the photo, you get an approximation, though the resulting texture is slightly contorted to bestow ‘spontaneity’.

seems legit

[Jan Vork]

In some cases it works to create Smart Objects for the added parts, and then add smart filters that blur the layer and sharpen it subsequently. Maybe ads some posterising to make color gradations less smooth. Be sure to get the color grading good before applying filters.