Why are images shown as distorted in Effective PPI

[mikaelabirath]

Hello!

I am adding in images (JPG) into an indesign file for printing. 
The images are too small so i am resizing them in photoshop. But after i have resized them, the effective PPI changes to 300x298 - meaning there is a distortion. But i dont understand HOW there is a distortion? 

I have added screenshots of the settings from the original image (that has an OK effective PPI in indesign, but is too small) and from when I have added in my changes. What am i doing wrong? I can size it up a little without it 'distorting' but i need it this big  to get the 300PPI and I don't know what to do

[jmlevy]

Hi @mikaelabirath I think that the answer has been given in your other post: images have not been scaled proportionnally.

See your screenshots:

About resizing the images in Photoshop: what you are doing is called upsampling and will result in a terrible loss quality.

[mikaelabirath]

Is there another way to do it other than upsampling? 

[jmlevy]

There is a feature in Camera Raw allowing to achieve a better result (it doubles the pixels number), but since I am using a French version, I don't know how it's called in English.

But don't expect miracle especially if you need to increase an image in very large proportions. You actually need to get a bigger image when you start your project.

If the final print is big, you don't necessary need 300 PPI images, you should check with your printer.

[Dave Creamer of IDEAS]

It's called "Enhance". 

[Dave Creamer of IDEAS · Accepted solution]

When you resize an image in InDesign, hold down the Cntl-Shift keys (Win) / Cmd-Shift keys (Mac) to keep the image and frame in proportion. It will place in proportion automatically. 

As far as upsampling is concerned, you enlarged a 72 ppi image so it's effective resolution is only 28 ppi. Probably not much you can go about that except get a better original. If you got this from the internet, be careful with usage rights. 

If you had a 72 ppi, it IS possible to upsample it in Photoshop, but ONLY as a last resort--better to try to get the original. See the PDF I've attached for typical results (a photo example is on page 2).

[Robert at ID-Tasker]

@mikaelabirath 

Because you work in MILLIMETERS in Photoshop - you should work in PIXELS.

[Robert at ID-Tasker]

@mikaelabirath 

Because you work in MILLIMETERS in Photoshop - you should work in PIXELS.

When you work in MM - the maths is "perfect" - there are rounding errors.