JPEG uses Discrete Cosine Transform to remove unobservable bits to eyes. If you are not happy with the photoshop quality, simply save it in 100% compression.
Thanks Macsoft3. I still have a question though: if the files look fine once I’ve saved them as a .jpeg in Photoshop, why the degradation once I upload to WordPress? Wouldn’t they suffer in quality once I save them as a .jpg?
Do I save it in 100% compression in Photoshop?
Thanks!
Wouldn’t they suffer in quality once I save them as a .jpg?
What are you saving them as? Yeah, you lose some quality if you upload as JPG or GIF. But those are pretty much universal filetypes, and all browsers recognize them. If you want really high quality, lossless images, save as PNG – but if they’re transparent in any way, you have to use extra code to make them show up right in IE6 and lower.
And yes, you save them as 100% in Photoshop.
And what browser are you viewing them in? (for example, if you’re viewing through AOL, your images are going to look like crap, no matter what you do.)
>Yeah, you lose some quality if you upload as JPG or GIF.
That depends. As for JPG, as I suggested before, if you use 100% compression, every bit will be recovered when it’s decoded (viewed).
>why the degradation once I upload to WordPress?
That’s probably because you are not doing it in the right way and not fully explaining what you are doing. If you don’t want to lose quality more than necessary, just use a hyperlink and display what you have instead of displaying the image that is further compressed in the course of uploading it to your FTP server through WordPress.
I don’t think WP “compresses” any image. It creates a thumbnail version of the uploaded image but I have never seen any image compressed by WP.
But the resolution is fixed and smaller than what it is in most cases, isn’t it, because the upload function doesn’t use interpolation like bicubic or bilinear? Anyway, I don’t have problems because I use hyperlinks to display original images.
Oh, I see. The upload function has changed a bit. moshu is right. An image will be stored as it is in the upload folder.
As for JPG, as I suggested before, if you use 100% compression, every bit will be recovered when it’s decoded (viewed).
Yeah. That’s true.
But I also agree with moshu – I don’t think WP’s upload function does anything other than create a thumbnail (so you can use it later if you want it) – so I don’t really think WP’s upload feature really has anything to do with the image compression that’s displayed. If you use the upload feature the image should look just the same as if you’d uploaded it yourself via FTP.
