[sane-devel] Canon XK90 2400dpi scanning possibility

[Ralph Little]

Hi,

On 2021-12-06 1:43 a.m., WATANABE Kazuhiro wrote:
> Hello,
>
> My Canon XK90 works fine with sane-pixma at all supported resolutions,
> up to 1200dpi.
>
> But on Windows XK90 is able to scan over 2400dpi.  Canon says that the
> maximum optical resolution is 2400x4800dpi:
>
>   https://ij.manual.canon/ij/webmanual/Manual/All/XK90%20series/JP/UG/ug-187.html
>   (written in Japanese)
>
> Can I scan XK90 with sane-pixma at 2400dpi?
>
>
> I've done an easy experiment with the following patch:
>
> --- sane-backends-1.0.32/backend/pixma/pixma_mp150.c.orig       2021-02-14 20:25:19.000000000 +0900
> +++ sane-backends-1.0.32/backend/pixma/pixma_mp150.c    2021-11-22 18:47:24.642433000 +0900
> @@ -1916,7 +1916,7 @@
>     DEVICE ("Canon PIXMA G2060", "G2060", G2060_PID, 0, 600, 0, 0, 638, 877, PIXMA_CAP_CIS),
>     DEVICE ("Canon PIXMA G3020", "G3020", G3020_PID, 0, 600, 0, 0, 638, 877, PIXMA_CAP_CIS),
>     DEVICE ("Canon PIXMA TS7430 Series", "TS7430", TS7430_PID, 0, 1200, 0, 0, 638, 877, PIXMA_CAP_CIS),
> -  DEVICE ("Canon PIXUS XK90 Series", "XK90", XK90_PID, 0, 1200, 0, 0, 638, 877, PIXMA_CAP_CIS),
> +  DEVICE ("Canon PIXUS XK90 Series", "XK90", XK90_PID, 0, 2400, 0, 0, 638, 877, PIXMA_CAP_CIS),
>     DEVICE ("Canon PIXMA TS8430 Series", "TS8430", TS8430_PID, 0, 1200, 0, 0, 638, 877, PIXMA_CAP_CIS),
>     DEVICE ("Canon PIXMA TR7600 Series", "TR7600", TR7600_PID, 0, 1200, 0, 0, 638, 877, PIXMA_CAP_CIS | PIXMA_CAP_ADF),
>     DEVICE ("Canon PIXMA TR8600 Series", "TR8600", TR8600_PID, 0, 1200, 0, 0, 638, 877, PIXMA_CAP_CIS | PIXMA_CAP_ADF),
>
> As a result, scanning at 2400dpi is done with the same amount of time
> as Windows.  But the acquired image is strange - two half-width
> squeezed (same?) images are concatenated left to right.
> Scan images are here:
>
>   https://drive.google.com/drive/folders/1ntc-_NRit1wak9vgF22GJZdgWy-YTqbr
>
>   1200.png       scan at 1200dpi
>   2400test.png   scan at 2400dpi with the patch
>
>
> If you need more information, please let me know.
Looks like the format is interleaved for 2400 dpi for this device.
I'm pretty sure that I have seen this before.

I will look into it.

Cheers,
Ralph