NOTE: The purpose of this web site is not to provide detail information regarding what these standards are but to dispel the myth that phdtv is better quality than pdtv or even equal quality. This will be done in two ways. The numbers and subjective quality.

The Problem

Several local broadcasters have begun to up sample pdtv to hdtv. The reason for this is many stations prefer to send only 1 signal, the HDTV signal. So whenever they get PDTV they change the resolution to meet HDTV standards. What does this up conversion of the resolution cause?. Some would say and increase in quality. But how can that be, quality does not come out of thin air. This method is exactly as if you took a 320x240 file converted to 640x480 (using the best resize filter). Although the image would be bigger the video quality would actually be worse. Why?, Because during any up scaling of resolutions more stuff is added but calculated from the original picture.

The Evidence

CASE #1 - ABC NETWORK

Sample 1A-Source ABC PDTV 720x480 Interlaced 29.97 FPS

Sample 1B-Source ABC PHDTV 1280x720 Progressive 59.94 FPS

Do not judge these thumbnails for quality, they are only here to show the complete image, they are jpeg compressed and also resolution has been downsampled to fit. For complete unaltered uncompressed bitmap click download above the images.

Let's take a look at resized portion of the sample. Both samples were resized to 512xXXX (Proper AR) via adobe photoshop bicubic resize. these images are PNG files to preserve quality. Note the extra noise, in the next set of images we will take a closer look at those color bursts

It's obvious from the edges that the pdtv has less noise than the phdtv. There is also another problem that sometimes occurs due to this upconversion. For that lets take a look at a zoomed edge of the light. Again this is Bicubic resized in photoshop. Also it's PNG.Take note of the color bursts around the edge

Case #2 - FOX NETWORK