If your store's product images look different than they did before you uploaded the images to - we have a way to fix it.
After reports from our customers about the "messy" generation of product images by PrestaShop, we decided to investigate and resolve the problem.
The reason turned out to be trivial and not entirely related to PrestaShop. Below is an explanation so that each of you will be able to deal with it on your own.
Here are two photos - on the left a photo before uploading to the store, on the right a photo that lost quality right after we uploaded it as a product photo in PrestaShop - the color saturation changed drastically.
The color change is blamed on the photo's color profile. To check the photo's color profile, open the photo in any graphics program, such as Photoshop. The photo on the left, which looks good, has an embedded "ProPhoto RGB" color profile, which renders the colors as it should, but only on a computer. When you upload the photo to a web application (PrestaShop), the photo loses its colors.
Converting the photo to the default Photoshop profile (e.g. sRGB IEC61966-2.1) and saving it using the "save for web..." option. will cause the photo to look the same both on your computer and when uploaded to the store.
The problem of a bad color profile of a photo can be diagnosed very quickly - by uploading the selected photo to an FTP server and opening it in the browser.
If you have a very large number of photos with the wrong profile, you can use your graphics program, such as Photoshop to create an automatic droplet to change the profiles of photos in bulk and save them correctly.