Problem cropping in iPhoto

[McT]

Hi there!

I work on a website, where I regular use the same size images (653x352px).
When I have a large number of images to upload, I select them all and resize them to 653 width with the preview-function. I then drag the images into iPhoto, choose the cropping tool and choose to make a "speciel format" in the drop-down menu (653x352px of course). That's a fast way to crop a lot of images at the same time. (if anyone has suggestions to a better/faster way - please let me know!)
Here is my problem:
When I have cropped the images to 653x352px - about half of the images have turned into 653x351px instead of 653x352px as I asked it to. It seems quite random, and there is no logic to it (as far as I'm concerned).
Do I do something wrong? I ask iPhoto to crop the images to 352px i height, and still it comes back in 351px. You might say, that it ain't even noticeable, and you're probably right, but our website has a setting, that only makes this excact size work, so 351px wont do!

Hope someone is able to help me!
Kind regards

 

[chscag]

Welcome to our forums.

Are you in fact still using iPhoto? Apple has long since abandoned iPhoto in favor of Photos which is similar. As for cropping the images, you could always try using Preview to do the cropping instead of iPhoto or Photos. Since you haven't really given us any info on your version of macOS or which Mac you have, our answers will be limited.

 

[badshoehabit]

If you are, in fact, using iPhoto, you are using an app which is no longer supported by Apple, having been replaced by Photos in 2015 which possibly explains the glitch you are experiencing. In Photos, resizing does not feature 'special format'. It has 'Custom' which, once set, stays at those proportions until changed manually.
I've not experienced the Custom mode changing the resultant size on its own. I don't understand why you are using both Preview and iPhoto/Photos when they can both achieve the same on resizing.