[imago-devel] convolve.lisp

[Thibault Langlois]

On 6/14/07, matthieu.villeneuve at free.fr <matthieu.villeneuve at free.fr> wrote:
> Hello,
>
> Selon Thibault Langlois <tl at di.fc.ul.pt>:
> > Hello,
> >
> > I think there is a small bug in the grayscale version of the convolve
> > method. Here is the diff:
> >
> > $ diff convolve.lisp convolve-orig.lisp
> > 64c64
> > <                               (incf sum (* (gray-intensity
> > (image-pixel image x2 y2))
> > ---
> > >                               (incf sum (* (image-pixel image x2 y2)
>
> That is correct, the faulty code probably remains from a version that
> didn't have alpha information in gray pixels. I'll fix that as soon as
> I can.
>
> > another detail: SBCL complaints about a declaration in color.lisp:
> >
> > $ diff color.lisp color-orig.lisp
> > 91,95c91
> > <   (let ((colormap
> > <          #-sbcl(make-array 256 :element-type '(unsigned-byte 8))
> > <          ;; make-color does not return an (unsigned-byte 8) sbcl does
> > <          ;; not like that.
> > <          #+sbcl(make-array 256)))
> > ---
> > >   (let ((colormap (make-array 256 :element-type '(unsigned-byte 8))))
>
> Do you have any idea where exactly SBCL complains? It does not on my
> machine, but I may not use the library the same way you do...
>
I get a warning:

; caught WARNING:
;   Asserted type (UNSIGNED-BYTE 8) conflicts with derived type
;   (VALUES (INTEGER 4278190080 4294967295) &OPTIONAL).
;   See also:
;     The SBCL Manual, Node "Handling of Types"

This happens if I compile the MAKE-SIMPLE-GRAY-COLORMAP function.

I noticed another missing gray-intensity in convert.lisp:

wok:~/comp/lang/lisp/code/imago$ diff convert.lisp convert-orig.lisp
45c45
<       (let ((gray (row-major-aref pixels i)))
---
>       (let ((gray (gray-intensity (row-major-aref pixels i))))


> Thanks for your time,

You are welcome, IMAGO is usefull so thank you !


>
>
> --
> Matthieu Villeneuve
>
>


-- 
Thibault Langlois
FCUL / DI