04-25-2019, 04:53 PM
(04-22-2019, 07:48 AM)Ofnuts Wrote:(04-21-2019, 10:01 PM)Fennec Wrote:(04-21-2019, 09:35 AM)Ofnuts Wrote: That blurry mess is JPEG compression artifacts. The tell-tale sign is the squareish pattern (JPEG compression first divides the images into 8x8 tiles):
So, your source image is crappy. With options B/C you keep the crap as it is. With option A, you blend the crap with the rest (because rescaling is computing new pixels values by cleverly averaging pixels in the image at the original size), so it goes under the radar (but participates in the general impression of blurriness).
As usual, Garbage In, Garbage out.
Ok, if I got a .PNG of this image, I assume it wouldn't have that jagged mess of compression artifacts? I think the reason I got a JPEG is because I needed the image to be a specific size and JPEG offers a smaller file size--at the expense of image quality I guess. It's strange, because when I zoom into the original JPEG, I don't see those artifacts. Dumb question, but I don't suppose you can convert a JPEG image to a PNG image since the source is already a crappy JPEG--it would just look the same?
Yes, once JPEG crap sets in it won't be removed by switching to a lossless format,it will just be carefully preserved. For CGI, PNG can do as good a job as JPEG with reasonable compression.
About the only way to get a better image from a jpg is to convert it to an SVG in inkscape or other SVG based program. You'll have to do a "trace bitmap" which will make it scalable to any size but it can only do so much with a sub standard original.