compression

Scott Wilkinson .... left in the dark

Scott Wilkinson

Episode 1588

The big news this week was the pivotal battle of Winterfell on Game of Thrones, and the problem was it was so DARK and badly lit. Scott says that it's almost as if the filmmakers didn't take into consideration that those who are streaming would be dealing with a heavily compressed image, that would crush the details in dark areas. Add the fact that it was the most watched episode in HBO history, it had to deal with congestion as well. The episode will no doubt look better on Blu-ray and in UHD. But with the heavily compressed signal of a 4K stream, it simply didn't.

How can I scan my photo at 72 dpi?

Episode 1177

Jim from Los Angeles, CA

Jim wants to enter pictures in a photo show and the show wants them as JPEGs at 72 dpi. He has to scan his images to do it. Leo says that 72 dpi is at very low quality and it's obviously an online gallery. But he can scan his images at the highest resolution possible and save it in TIFF. That would be lossless compression. He can always open it in a photo editor and then lower the resolution to JPEG. Leo recommends Irfanview.

Scott Wilkinson

Scott Wilkinson

Episode 1113

Scott is back to talk about compression. Leo says that MP3 (or AAC for Mac) powered the music download revolution because it eliminated over 90% of the file size through compression. But now that we're in the broadband era, could we get back the lossless compression like FLAC? Scott says that the dirty secret about hi-res audio is that in many cases, music companies are taking the same CD files and just resamplling them. So you're not really getting a lossless file. Leo says that would be a rip off if it's true.

Why does AT&T's U-verse look so compressed?

AT&T U-verse

Episode 1071

Rob from Fairfield, CA

Rob has AT&T UVerse and looks really compressed. Leo says he hears that complaint all the time. It's likely that U-Verse does use a lot of compression, even though it's fiber, so they have no loss of bandwidth. On top of that, channels also are compressed. So there's compression all along the line. This is why broadcast HD is always the best, because there's no compression over-the-air.

How can I get better images on my digital picture frame?

Episode 1050

Carlo from Ontario, CAN

Carlo wants to create a digital picture frame with an HD display, but the quality hasn't always been great. Leo says it's probably because he's using JPG files that when blown up large, it shows artifacts. Leo suggests exporting higher quality images, but Carlo says the JPGs are 36 Megapixels. Leo says it's not the megapixels, but the file size. JPG is what we call a "Lossy" compression technology, which takes little bits out that wouldn't be noticed at smaller sizes. If he uses a lossless compression, such as the TIFF file format, then every dot from the original image will be intact.

Why do my website images have artifacts?

Episode 1040

Charlie from Lakeland Village, CA

Charlie and his wife are starting a bakery website, but he's having trouble cleaning up the images he took with his camera phone so they look nice and clean. Leo says that the artifacts he's seeing may be due to low light or highly compressed images. He recommends trying to take photos with a better camera. Or, take the subject out of the image using Photoshop.

What is the better format for video storage, AVI or MPEG?

Episode 879

Sunana from Boulder, CO

They are not mutually exclusive. AVI, MOV, Flash, MKV and others are actually wrapper formats. They can contain MPEG video within them. It doesn't matter what format she uses, any of those are fine. But Leo does recommend using a compression, or CoDec (Compression/Decompression) called H.264. That will give the best quality while still maintaining a smaller file size. It's also rapidly becoming a standard.

Visit Sunana's home cooking show site at DinnerAtYourHouse.com.