Legacy ImageMagick Discussions Archive

Version 6.9.9-34 works fine.

I found it.
I must use version 6.6.4-Q16 and not 6.9.9-27 Q8.
Version 6.9.9-27 Q8 failed to create 8 bits single channel.

The corrected program does not create 8 bits single channel any more.
Source code not changed.
Only i deinstalled all ImageMagick versions to reinstall V6 clean.

I do not understand why the corrected program suddenly create 24 bits images (8/hannel 3 channel).
Any idea what is gone wrong?

Version ...

Perfect, MagickSetCompression is the right one, now everything is ok.
I could convert the image to 8 bits single channel no compression.

Thank you for your help.

sorry but compression is set to : '8-Bit RLE' it must be set to 'None'

I rearranged the instruction as you worte but i get 24 bits instead of 8.
It does not work using C API but strangly works for command line.

Anyway thanks for your help.

Do you mean that ImageMagick can not create 8 bit single channel 256 colors ?
Then please look at the following command line: it creates correctly 8 bit single channel

"C:\Program Files\ImageMagick-7.0.2-Q8\magick" tmp.bmp -resample 500x500 -resize 344x360 -grayscale Rec601Luma -depth 8
-alpha ...

Hi,
I am back again.
Our machine does not accept the 24bits image.
I found out some interresting docs in https://www.imagemagick.org/script/porting.php#imv7
It is stated there the following:

Grayscale
Previously, grayscale images were Rec601Luminance and consumed 4 channels: red, green, blue, and ...

Okay,
I will make a try to pass the image to our machine.
If it can process it then everything is ok.
Thanks.

Thanks for your reply.
You'r right. Now i have version 7 clean reinstalled (destroying all version 6 directories),
and use 'MagickWand\MagickWand.h'. The 'biCompression' is set now correctly to 0.
But the result image is 24 bit and not 8 bit as i explicitly used MagickSetImageDepth(wand, .

Hi,

Using C API I want to convert a .bmp file to a .bmp with the following properties:

color depth 8bits
colorspace grayScale
resolution 500x500 ppi
size 344x360
NoCompression

According to bitmap file format referenced in https://en.wikipedia.org/wiki/BMP_file_format:
The C API converted image ...