Performance and PNG's

[mtdimich]

We are looking at using ImageMagic to convert multiple page PDF's to PNG colour type 3 images. First question:

The syntax I used to create the type3 PNG's was:
convert inputFile -type Palette outputFile

Will that give me a PGN with colour type 3? Or is there a way to verify that?

Second question:
How does ImageMagic scale from a performance perspective? Is there any data as far as conversions/min of any type out there for ImageMagick?

Thanks!

[glennrp]

You can check the PNG color type with

• identify -debug coder -log %e file.png

and look for a line saying "PNG color_type N"

The performance of writing PNG files is mostly governed by the
time used in the "deflate" compression which is proportional to
the number of pixels in the image.

[mtdimich]

Thanks,

Now I thought that I was using the right syntax to create a PNG with color type 3 but it turns out I wasn't. I have tried:

convert image.pdf -type Palette outimage.png

and

convert image.pdf -channel Index outimage.png

Any thoughts?

Thanks!
Matt

[glennrp]

Thanks,

Now I thought that I was using the right syntax to create a PNG with color type 3 but it turns out I wasn't. I have tried:

convert image.pdf -type Palette outimage.png

and

convert image.pdf -channel Index outimage.png

Any thoughts?

Thanks!
Matt

• -colors 255