Pixelated Image after save as

[william_rubin]

My negs were scanned to CD (jpg) at the lab. I did touch up work on my Mac (as I always

do) and saved the updated jpeg files to my hard drive. Now when I open the file the image

is obviously pixelated. You can't see it at first glance but when zoomed in a little there is

a problem.

 

I've worked this way in the past and the images have never pixelated like this before. (The

horizontal and vertical lines creating boxes and making up the images show.) When I've

done this in the past the touched up images still appear like slightly grainy film when

zoomed in.

 

Can anyone tell me what happened and how to fix it? Thanks!

[alexdi]

Use a lower compression setting or save in a non-lossy format. TIFF, say.

 

DI

[william_rubin]

I appreciate your response. Do you know why this would happen? It's never happened

before. I touched up several photos (a lot of hours-ugh!) and now they look like ***. Is

there a way to fix them so I don't have to redo all of my work?

[hsksla_ddygff]

best to work on image as TIFF, each time you "save as" JPEG you lose image quality, best to complete work in TIFF and save as jpeg your last step.

[alexdi]

Maybe. Post a sample crop and I'll tell you soon enough.

 

DI

[william_rubin]

Here is the original jpg from a scanned neg.<div></div>

[william_rubin]

Here is a smaller original.<div></div>

[william_rubin]

Here is the original saved after touch up as a jpg. Why the obvious pixels??<div></div>

[paul -]

Those blocks aren't pixels, those are jpeg artifacts. A pixel wouldn't be that large, or have multiple tones in it. Artifacts are the expected result from over-compressing and re-saving jpegs.<p>Since the "original" scan doesn't have them, you are introducing them when resaving. After editing the image, resave as TIFF and you shouldn't have this problem.

[william_rubin]

Thank you for your reply. jpeg artifacts huh...learn something new every day. So can i

save my work from this or do i need to go back to the original and redo the touch ups,

which are many? I can't figure out why it did this on all of my recent work but hasn't done

this in the past. Did I do something?

 

If my lab requests jpeg. Should I save as tif and then save a second one as jpeg? How can

i avoid this in the future?

 

Thanks again.

[digitmstr]

JPG is a LOSSY compression that is, everytime you click SAVE it will compress, and compress, etc... Do the following:

 

1) CONVERT the *original* pictures you want to EDIT in TIFF format.

 

2) do ALL the editing and SAVE as TIFF

 

3) Convert to HIGH quality JPG for your lab

[alexdi]

What he said. Presumably you've got a pretty good idea what you did, so perhaps it won't take so long the second time around.

 

Good luck,

 

DI

[william_rubin]

I did what you said and it worked. I just can't understand why I never had this

problem before. But then again, maybe I did have the artifacts before and

didn't notice it until now. Thanks again!