what wcompress error means

I want to compress an image using

wcompress( 'c','bmp1.bmp','compimg1.wtc','stw');

But I get an error Subscripted assignment dimension mismatch. What this error means?

[Walter Roberson]

I suggest experimenting with

img - imread('bmp1.bmp');
wcompress('c', img, 'compimg1.wtc', 'stw')

Answer 1

[cev]

x,y dimensions of image should be power of 2

Answer 2

[Bruno Pop-Stefanov]

There seems to be a bug in either wfandfcidx or wavedec2, which are internal functions called by wcompress. I am sorry I can't help you more, but until this bug is fixed you can try another compression method. EZW, SPIHT, and SPIHT 3D should work (I get the same error with WDR and ASWDR). Good luck!