Change ppi without changing size in InDesign

[amanm5143]

Hi,

I am working on a project of around 2000+ documents which needs to be sent for printing with a specification wherein, the images need have atleast 300 ppi. However, few of the images do not have the same properties. Hence, I was wondering if there was a way to change the ppi of the image without scaling it, in InDesign? Else, is there a script or plug-in which can convert the image in Photoshop and update it back in InDesign?

I found an alternative solution for this on InDesignSecrets - https://indesignsecrets.com/raise-image-resolution-directly-in-indesign.php

https://indesignsecrets.com/raise-image-resolution-directly-in-indesign.php

The problem is I don't have images in one layer and and text in another layer. I have everything in one layer in all the documents.

Any kind of guidance, would be highly appreciated.

Thanks & Regards,

Aman Mittal

[good_Glimpse01AC · Accepted solution]

InDesign does not contain the ability to adjust image resolution directly. The article you found shows an interesting trick to make it happen though. I would create a preflight profile in InDesign to flag any images with an effective resolution below 300 so that you can easily identify which images are problematic. Then you can open them in Photoshop and increase the resolution. Or…

• Use the trick in the article above by just putting the white image on the master page to effect each and every image in your document
• Try the Zevrix plug-in which will allow you to resample the images to an appropriate resolution

[amanm5143]

Hi Chad,

Thank you for taking out the time and replying to the discussion. Certainly, I did the same thing with Pre-flight Panel for identification of below 300ppi images. However, in order to improve the resolution, I would have to scale down the images by a considerable percentage, based upon the formula (ppi/300*100) which makes low ppi images tiny. Hence, I have been trying to figure out a way to change the resolution without changing the size to a great extent.

The trick is definitely amazing however, it works when we have images in one layer and text in another. In my case, everything is under a single layer thereby, not allowing me to use the trick.

I will definitely try the plug-in to see if it solves the issue. Thank you for putting up a prospective solution. Highly appreciated!

Thanks & Regards,

Aman Mittal

[good_Glimpse01AC]

You should still be able to very easily try the trick. Layers apply to every page in the document including the master. On the master page that is applied to all of the document pages, create a new layer. Call it Image Trick or something. Move that layer above all other layers and put the white image on that layer. That will now apply to every page! Follow the steps in the link above and you should be good to go.

[Test Screen Name]

If the images do not have 300 ppi, you either need to reduce them on the page, or source a higher quality original. You cannot magically increase to meet a quality requirement.

[Derek Cross]

That's true, but enlarging an image in Photoshop a little and adding a bit of unsharp mask will often be "good enough" (depending on the kind of work you're doing).

[amanm5143]

Hi Derek,

Thank you for the response. You are right on this front. I am trying to figure out if there is a script/plugin or something to that extent, which could semi-automate the process.

Thank you for the help!

[rob day]

How far below the 300ppi threshold are the resolutions? 300ppi is a rule-of-thumb not a requirement. The required resolution really depends on a the image’s content— are there details in the image, I.e., fine hair against a contrasting background, vs. soft clouds, that would benefit from higher resolution? In almost all cases upsampling those kind of images will simply blur the details. For some kinds of images (I.e., screen captures) an upsample will do more damage than good.

Is the the printer going to reject the job or simply ask you to sign off on the lower resolutions?

[amanm5143]

Hi Rob,

Thank you for taking out time to reply to the thread. You are right about the contents of different images so, as suggested, the problem has been resolved by signing off for the moment.

Thank you for the help!

Regards,

Aman

[amanm5143]

Hi,

Thank you for the response! I understand that perfectly. However, if I can come near to the requirement that would be fine as well. As rightly put by Mr. Derek, making a few adjustments in Photoshop could do the trick. I was just trying to figure out if there was a plugin or something to that extent, which could have semi-automated the process.

Thank you for the help!

[Willi Adelberger]

Enlarging would not help much anyway. The most common way is, as InDesign Secrets state in several articles, place the images in RGB with color profile and recalculate at the export to PDF from InDesign.

You write about text in your image. If a photoshop file contains text or vector, don't include it in any smart object, keep it as layer as it is and safe it as Photohop PDF (also has the extension PDP) with default settings (don't alter anything) and place this PDF or PDP in InDesign as it keeps the font alive and does not rasterize vector elements. This will increase the quality.

[Sandee Cohen]

Will,

I believe the original poster means that the text and images in InDesign are on the same layer, not layers in Photoshop.

[amanm5143]

Yes! Rightly said!

[amanm5143]

Hi Willi,

Thank you for the reply. The images are already in RGB colour in InDesign. If possible, could you please elaborate on the recalculation part of the export? How would you do that?

Thanks!

[Sandee Cohen]

Are you exporting to PDF? If so, there is a compression setting in the PDF dialog box that will DOWNSAMPLE images that are over 300 ppi to 300. But it won't upsample. I think that's one of your desired results.

There is a way to create an action in Photoshop to resample to 300. Then that action can be part of Photoshop's Automate command. But when you run that action in Photoshop and then save/update the images. The problem there is the image stays at the same magnification. This may not give you results you want.

I have a shocking idea to follow the print shop's requirements.

You can't be the only company who creates files with overly low resolution images. Why not ask the print shop what other of their clients do? Or, ask them to put you in touch with other clients to find out what they have done.

[amanm5143]

Hi Sandee,

Thank you providing a solution through Photoshop. Much appreciated. This is a good alternative though I understand that the magnification might affect the quality of the image. As suggested, I spoke to the printing partner and was asked to sign off on the low resolution. So, for the moment, the problem is resolved.

Thanks a lot!

Regards,

Aman