Specify the units – I seem to remember having a problem when I omitted this option (although DPI should be the default), for example: convert. convert -units PixelsPerInch -size x xc:black -resample 96 The GIF format actually totally ignores/discards the dpi anyway, as you can see diff finds. #resample. As for your screen — measure it! it is typically (these days) 90 to dpi. Remember dpi.

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conversion – Convert image with imagemagick command line convert tool – Unix & Linux Stack Exchange

Maybe someone else can use it. Sign up or log in Sign up using Google. If you ‘print’ it at dpi on a 1 inch square, it’s no longer the same image: Yes it is a little archaic. That’s the reason why you made this discovery: Sign up using Facebook. Therefor it is info that only PNG image data, x8-bit grayscale, non-interlaced When I use this command, it seems like it did what I wanted: By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Since it is still not clear to some readers what I noted above, here is one more attempt Attributes, Properties and Artifacts http: Stack Overflow works best with JavaScript enabled. By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

That is -density is being dual purposed as both a input setting for images that is created and read in, and as image meta-data modifier operator after images have been read in. IF an image viewer understands it, it will render the image larger or smaller to meet that DPI request, but it will not change the image per se. Is it a bug? Do you know which embedded data fields GIMP uses to read the resolution – does it have its own that override the standard ones used by ImageMagick?


Thanks for any help in this. I discovered that pngcrush not an ImageMagick tool can also add the density metadata. Post Your Answer Discard By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies.

This way we can help to solve the problem.

Why does ImageMagick always convert to 96 dpi? – Stack Overflow

However they both probably should be set after reading the image. If you’re concerned about both reliability and speed, then I recommend ignoring that statement about DPI and just experimenting.

Does -resample use a different algorithm for scaling from -scale? Funny enough, the same output comes for input.

Photoshop stores its hints about a desired print or display resolution in a proprietary profile named 8bim. Cnvert Wilson 1, 1 9 Ok, the values there are often 72 by default.

Sign up using Email and Password. So what remains is this: Post as a guest Name. But it does just not do what I want. The article here explains the DPI rather well. I’m not entirely clear in understanding what these requirements mean with respect to a file. According to these two pieces of info Gimp then calculates the total number conver pixels it has to use extrapolate from the original number of pixels to fill the requested space at the requested resolution.


This is not the case. How can I measure my screen?

Secondly, DPI should not be confused with resolution. This photo cpnvert I want to convert will for internal use of government office only. Charles Boling 2.

That is the first info. It is for this reason imageagick many options such as -label is strictly a input setting only, while -set label is strictly used as a meta-data attribute changing operator! In other words it is more than likely that the two aspects are causing buggy behaviour.


The images will appear smaller in the resulting PDF but with high printing quality. Sumanta Pakira 2 13 That’s the reason why you made this discovery:. It is just a hint which a printing or rendering device or an application may or may not follow when printing, rendering or displaying the image. This ‘hint’ can possibly be automatically evaluated by printer drivers or by page creation programs such as LaTeX.

Home Questions Tags Users Unanswered. And ImageMagick’s documentation is in full agreement with me: Maybe I was talking too technical, and was not clear enough?