There has been some discussion in the forum recently concerning the relative sharpness of various capture formats. After much back and forth on this I decided that some actual tests were in order.
How to do it? Here's what I came up with;
1. send a live video feed of a test image to the capture card. I used a U.S. Air Force lens test target and a Sony Hi8 cam. The target was 3 meters from the cam and the lens was adjusted to have the target fill the frame.
2. capture 1000 video frames to 704x480 *.avi's using each of the formats under discussion;
YUY2 raw
HuffYUV 2.1.1 @ "best"
Matrox MJPeg @6.6:1 compression
3. import these clips into Premiere 6.0 and export a 704x480 *.bmp from the middle of each *.avi.
4. crop the images to allow for faster downloading. They were then joined into a single *.bmp in Photoshop and labeled.
5. this image was then converted to a 100% quality first generation JPEG to make it small enough for downloading with a 56k connection (150k).
The resulting images show the actual image quality of the video capture, not what shows up on the monitor during playback or in PC-VCR etc. Guess which is most important?
You can judge their quality and sharpness for yourselves. The page may be a tad slow on a 56k connection due to the image being 150k in size.
http://hometown.aol.com/videoschool/...age/index.html
Yes, HuffYUV does optimize the YUY2 frame a bit. IMHO this makes it even more desirable to use.
IMHO MJPeg is NOT sharper by any stretch. The Gibbs artifacts and quantization used in DCT codecs prevent that.
Dr. Mordrid
[This message has been edited by Dr Mordrid (edited 16 January 2001).]
How to do it? Here's what I came up with;
1. send a live video feed of a test image to the capture card. I used a U.S. Air Force lens test target and a Sony Hi8 cam. The target was 3 meters from the cam and the lens was adjusted to have the target fill the frame.
2. capture 1000 video frames to 704x480 *.avi's using each of the formats under discussion;
YUY2 raw
HuffYUV 2.1.1 @ "best"
Matrox MJPeg @6.6:1 compression
3. import these clips into Premiere 6.0 and export a 704x480 *.bmp from the middle of each *.avi.
4. crop the images to allow for faster downloading. They were then joined into a single *.bmp in Photoshop and labeled.
5. this image was then converted to a 100% quality first generation JPEG to make it small enough for downloading with a 56k connection (150k).
The resulting images show the actual image quality of the video capture, not what shows up on the monitor during playback or in PC-VCR etc. Guess which is most important?
You can judge their quality and sharpness for yourselves. The page may be a tad slow on a 56k connection due to the image being 150k in size.
http://hometown.aol.com/videoschool/...age/index.html
Yes, HuffYUV does optimize the YUY2 frame a bit. IMHO this makes it even more desirable to use.
IMHO MJPeg is NOT sharper by any stretch. The Gibbs artifacts and quantization used in DCT codecs prevent that.
Dr. Mordrid
[This message has been edited by Dr Mordrid (edited 16 January 2001).]
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