Legacy ImageMagick Discussions Archive

Hello There,
I have followings:
SELS 10.04 64 bit
Nginx nginx 0.8.20
ImageMagick version: ImageMagick 6.7.8

I wrote an image compressing module of nginx with imagemagick, but now I encounterer with an error:
1. the temp directory is filled with image magick dumpped files such as:
-rw------- 1 root ...

fmw42 wrote:Sorry I cannot help. I do not use any API just the command line.

Thank you all the same.

fmw42 wrote:depth is per channel, so multiply by the number of channels

Thanks. But I get zero as number of channels. As i got code:
Thanks for your clearation.

I'm using MagickCore to get depth of png files, (Version ImageMagick-6.7.8 ) but it doesnot work correctly, I have 32-bit and a 8-bit png pictures, but im tells them depth are same as 8-bit, it's so strange.
Image *images = NULL, *thumbnails = NULL;
ngx_buf_t* buf = NULL;
size_t len;
u_char ...

Crap, your completely right. I add such code：
QuantizeInfo *q_info = AcquireQuantizeInfo( image_info );
q_info->number_colors=256;
q_info->dither = MagickFalse;
QuantizeImage(q_info, thumbnails);

it all makes sense now. I wasted so much time trying to figure this out. Thanks a lot.

I'm using MagickCore to convert images from 24bit to 8bit (Version ImageMagick-6.7.8 )， but it doesnot work. And I've got code :

Image *images = NULL, *thumbnails = NULL;
ngx_buf_t* buf = NULL;
size_t len;
u_char *inputblob = NULL, *outputblob = NULL;
ImageInfo *image_info = NULL ...

Any conversion to jpg, even with -quality 100, will cause some loss of quality. JPG is a lossy compression format. If you want lossless, then you could use JP2000.


Thanks. But I want to make sure wether it will cause some loss of quality to convert to png or gif.
Othermore, wether there are ...

Q1: When using ResizeImage() func, will there be quality loss?
Q2: When convert an image from png(or gif) format to jpg format, can it cause some question about quality loss?

IM Version: ImageMagick 6.7.8-3 2012-09-11 Q16
MagickCore API
Q1:

Image *zoomimage = ResizeImage(image, width, height ...