seqdist prints the mean square error (MSE), signal-to-noise ratio (SNR), peak signal-to-noise ratio (PSNR), or maximum absolute error (MAE) between image sequences seqfile1 and seqfile2 to stdout.
The options -mse, -snr, -psnr, and -mae indicate in which form the distortion should be expressed. If none of these options are specified, seqdist prints the distortion in all forms.
If the option -vo is specified, then seqdist prints a terse output, consisting of only the value of the distortion, to stdout. One of the options -mse, -snr, -psnr, or -mae must be specified in this case.
The options -sf and -ef specify the starting and ending frame numbers, respectively, over which to calculate the distortion. If either of these is not specified, seqdist determines the first and/or last frame automatically from the files that exist via QccIMGImageSequenceFindFrameNums(3) .
If the -w option is not given, the distortion over each individual frame is printed. Additionally, in the case of verbose output (-vo not given), the distortion over the entire sequence (or relevant subsequence, in the case that -sf or -ef are specified) is output. If -w is given, only this latter distortion is output.
If the image files are color, the distortion calculations are performed separately for the Y, U, and V components of the image. The distortions for each image component are output in order.
For the calculation of SNR and PSNR, seqfile1 is considered the original signal; seqdist thus finds the variance of seqfile1 for use in the SNR calculation. For the calculation of PSNR, seqdist assumes that the peak-to-peak range of seqfile1 is 255 levels.