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Image quality. You have the choice between two of the major file formats: JPEG and PNG. Both are well established among browsers. JPEG has a good compression ratio, but can result in visible artifacts. PNG's compression algorithm is not as good as JPEG's, but there are comparatively fewer visible artifacts; nonetheless, older browsers might not recognize this format.
Choosing between one or the other is often a matter of taste. That being said, JPEG remains the recommended choice. If you would rather prevent information loss because of a format change, choose the second option, "Use PNG only if the base image is in PNG format".Warning PNG format is not compatible with the "Watermark" module.
- JPEG quality. Do not choose anything below 80 or at worst 75, for fear of visible compression artifacts.
- PNG quality. Do not choose anything over 6 or at worst 7, for fear of visible compression artifacts.
- Image generated by. This feature allows you to position the product image in its pre-established space:
- Choose "height" in order to fill the frame height (the width is then recalculated to maintain the same height/width ratio as in the file of origin).
- Choose "width" so that the image fills the width of the frame (the height is then recalculated to maintain the same proportion).
- Choose "auto" so that the width and height are calculated to maximize the space it can occupy in the frame.
- Maximum size of product pictures. Your customers can upload pictures for customized products. By default, PrestaShop sets this value to the PHP maximum setting – this can mean several megabytes: for instance, 8,388,608 bytes means 8 Mb. You can expand this value if necessary, but make sure that your PHP installation is able to take file uploads of this size.
- Product picture width. By default, customers can upload image with a maximum width of 64 pixels.
- Product picture height. By default, customers can upload image with a maximum height of 64 pixels.
- Use the legacy image filesystem. Only change this setting if you have moved the images folder from its default location.
Regenerate Images
You may be dissatisfied with your shop's current thumbnails size. This section makes it possible for you to regenerate them all – or only those for a specific type of content:
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