Hi devs, Currently the image plugin [1] allows us to create image thumbnails by specifying the image width and/or height in the query string of the image attachment download URL: /xwiki/bin/download/Spage/Page/image.jpg?width=100 I propose that we: (A) Use the image width and/or height (when they are specified in the image syntax using pixel unit) to resize the image on the server side. For instance: [[image:logo.jpg||width="100px"]] will be linked to /xwiki/bin/download/Spage/Page/logo.jpg?width=100

and [[image:logo.jpg||style="height: 50px; width: 70px"]] will be linked to /xwiki/bin/download/Spage/Page/logo.jpg?width=70&height=50 The image plugin also accepts a quality parameter that controls the compression quality when encoding jpeg images. The default value of this parameter (i.e. when not specified in the URL) is configurable. I propose we use 0.3 by default, 1 representing the best quality. (B) Add the ability to limit the image dimensions (preserving aspect ratio) when the image width and/or height are not specified in the image syntax (or when they are not using pixel unit). The width and height limit will be configurable and -1 by default (i.e. no limitation). For instance: image:logo.jpg will be linked to /xwiki/bin/download/Spage/Page/logo.jpg?width=1024 when width limit is 1024, and to /xwiki/bin/download/Spage/Page/logo.jpg?width=1024&height=768&keepAspectRatio=true when width limit is 1024 and height limit is 768. Note that in this case the image aspect ratio is preserved. The image is resized to best fit the limits. If the user want to bypass the limit he has to specify the image width/height in the image syntax.

I'm +1 for both (A) and (B). WDYT? Thanks, Marius [1] http://svn.xwiki.org/svnroot/xwiki/platform/core/trunk/xwiki-core/src/main/… _______________________________________________ users mailing list users(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/users

On 09/08/2010 11:40 PM, Marius Dumitru Florea wrote: If I remember correctly this would mean that we give special meaning to some parameters (right now they are automatically copied to HTML attributes of the element). I don't remember exactly why, but I think this was an issue (Thomas? Vincent?) otherwise I would be +1 for this, image will be resized anyway, and let's hope the image plugin can do it as well as the browser would (in terms of quality of the result).

I would say we would need a way to bypass and say "original size", be it a special value of the width (negative) or another method. +0 for B _______________________________________________ users mailing list users(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/users

On 09/08/2010 11:40 PM, Marius Dumitru Florea wrote: If I remember correctly this would mean that we give special meaning to some parameters (right now they are automatically copied to HTML attributes of the element). I don't remember exactly why, but I think this was an issue (Thomas? Vincent?)

otherwise I would be +1 for this, image will be resized anyway, and let's hope the image plugin can do it as well as the browser would (in terms of quality of the result).

I would say we would need a way to bypass and say "original size", be it a special value of the width (negative) or another method.

+0 for B _______________________________________________ users mailing list users(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/users

Marius Dumitru Florea wrote:

This seems to be fuzzing the line between url parameters and html tag attributes. why not just use [[image:logo.jpg?width=100px]]

Parsing CSS and extracting widths and heights for server side scaling?

+1 B

A I need to hear more about how it will be implemented, from what i read it doesn't look right.

Caleb _______________________________________________ users mailing list users(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/users

Hi Caleb, On 09/09/2010 02:22 AM, Caleb James DeLisle wrote: First of all, you make the assumption that users know what a URL query string is. I don't fully agree with this. Then some users might get confused if there are two ways of specifying image width/height: should we put the width/height in the image reference or in the image parameters? Finally, writing: [[image:logo.jpg?width=100||width=50px]] makes no sense. Why would you want to download a 100px image when you display it at 50px only. Also, IMO wiki syntax is independent from HTML. When you write: [[image:logo.jpg||width="100px"]] "width" is a parameter of the image. This wiki syntax could be rendered in many formats. One of these formats is HTML, but it's not the only one. When rendered in HTML the width parameter is mapped to the width HTML image attribute but that doesn't mean we can't use the width parameter for other things, like adjusting the image URL. IMO what's really important is to honor user expectations. When a user writes: [[image:logo.jpg||width="100px"]] he expects to see the logo.jpg image displayed and its width to be 100px. My proposal doesn't change this. Resizing the image on the server is an optimization and I think most of the users will be happy with it (the page will load faster).

Yes, using http://cssparser.sourceforge.net/ .

As Thomas said, it will be implemented in a XWiki specific implementation of WikiModel ( http://svn.xwiki.org/svnroot/xwiki/platform/core/trunk/xwiki-rendering/xwik… ). We're going to add a method to get the image URL based on: document reference, attachment file name and image parameters. The implementation looks for the width, height and style parameters and tries to extract image width/height from them. If it succeeds then it adds this information to the query string of the attachment download URL. When the image is requested by the browser the image plugin is called and it uses the width and height request parameters (if specified) to scale the image attachment. The image size is never increased. The image plugin uses a component for image processing (decode, scale, encode). The default implementation of this component uses javax.imageio and java.awt classes for image processing. Thanks for your feedback, Marius _______________________________________________ users mailing list users(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/users

On 09/09/2010 12:18 PM, Caleb James DeLisle wrote: Right now the common use case is when a user resizes an image from the WYSIWYG editor using the image resize handlers. The browser puts the width and height information in the style attribute. I can move the width and height to the corresponding attributes afterwards but: * The style attribute is still required when width and height are not expressed in pixel or percent. This won't happen often but the user can explicitly set the width/height to other units like em in the edit image WYSIWYG wizard. * The user can still write: [[image:logo.jpg||style="height: 50px; width: 70px"]] in the wiki editor and the image will be displayed as expected. I admit that the style parameter for image syntax (and not only) is HTML oriented but I think it's ok to parse it in order to optimize page loading speed.

Thanks, Marius _______________________________________________ users mailing list users(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/users

On 09/09/2010 02:14 PM, Caleb James DeLisle wrote: > > Marius Dumitru Florea wrote: > >> On 09/09/2010 12:18 PM, Caleb James DeLisle wrote: >> >>> Marius Dumitru Florea wrote: >>> >>>> Hi Caleb, >>>> >>>> On 09/09/2010 02:22 AM, Caleb James DeLisle wrote: >>>> >>>>> Marius Dumitru Florea wrote: >>>>> >>>>>> Hi devs, >>>>>> >>>>>> Currently the image plugin [1] allows us to create image thumbnails by >>>>>> specifying the image width and/or height in the query string of the >>>>>> image attachment download URL: >>>>>> >>>>>> /xwiki/bin/download/Spage/Page/image.jpg?width=100 >>>>>> >>>>>> I propose that we: >>>>>> >>>>>> (A) Use the image width and/or height (when they are specified in the >>>>>> image syntax using pixel unit) to resize the image on the server side. >>>>>> For instance: >>>>>> >>>>>> [[image:logo.jpg||width="100px"]] >>>>>> >>>>>> will be linked to >>>>>> >>>>>> /xwiki/bin/download/Spage/Page/logo.jpg?width=100 >>>>>> >>>>> This seems to be fuzzing the line between url parameters and html >>>>> tag attributes. why not just use [[image:logo.jpg?width=100px]] >>>>> >>>> First of all, you make the assumption that users know what a URL query >>>> string is. I don't fully agree with this. Then some users might get >>>> confused if there are two ways of specifying image width/height: should >>>> we put the width/height in the image reference or in the image >>>> parameters? Finally, writing: >>>> >>>> [[image:logo.jpg?width=100||width=50px]] >>>> >>>> makes no sense. Why would you want to download a 100px image when you >>>> display it at 50px only. >>>> >>>> Also, IMO wiki syntax is independent from HTML. When you write: >>>> >>>> [[image:logo.jpg||width="100px"]] >>>> >>>> "width" is a parameter of the image. This wiki syntax could be rendered >>>> in many formats. One of these formats is HTML, but it's not the only >>>> one. When rendered in HTML the width parameter is mapped to the width >>>> HTML image attribute but that doesn't mean we can't use the width >>>> parameter for other things, like adjusting the image URL. >>>> >>>> IMO what's really important is to honor user expectations. When a user >>>> writes: >>>> >>>> [[image:logo.jpg||width="100px"]] >>>> >>>> he expects to see the logo.jpg image displayed and its width to be >>>> 100px. My proposal doesn't change this. Resizing the image on the server >>>> is an optimization and I think most of the users will be happy with it >>>> (the page will load faster). >>>> >>> I can see the logic in this. >>> +1 >>> >>> >>>>>> and >>>>>> >>>>>> [[image:logo.jpg||style="height: 50px; width: 70px"]] >>>>>> >>>>>> will be linked to >>>>>> >>>>>> /xwiki/bin/download/Spage/Page/logo.jpg?width=70&height=50 >>>>>> >>>>> Parsing CSS and extracting widths and heights for server side scaling? >>>>> >>>> Yes, using http://cssparser.sourceforge.net/ . >>>> >>> 'IMO wiki syntax is independent from HTML. When you write [...] >>> "width" is a parameter of the image. This wiki syntax could be >>> rendered in many formats.' >>> >>> >> >>> After thinking it over I agree but now aren't we risking an too much >>> dependence on CSS? It seems a bit odd to have a CSS parser for only >>> one job and specifying style in an html attribute is WCAG invalid. >>> Is there a common use case? >>> >> Right now the common use case is when a user resizes an image from the >> WYSIWYG editor using the image resize handlers. The browser puts the >> width and height information in the style attribute. I can move the >> width and height to the corresponding attributes afterwards but: >> >> * The style attribute is still required when width and height are not >> expressed in pixel or percent. This won't happen often but the user can >> explicitly set the width/height to other units like em in the edit image >> WYSIWYG wizard. >> * The user can still write: >> >> [[image:logo.jpg||style="height: 50px; width: 70px"]] >> >> in the wiki editor and the image will be displayed as expected. >> >> I admit that the style parameter for image syntax (and not only) is HTML >> oriented but I think it's ok to parse it in order to optimize page >> loading speed. >> > It still doesn't sound right to me but I'll trust your judgment here. > > 0 > > Caleb >

I think the best way would be to have this configurable in, for example, xwikipreferences. This way, it wouldn't sound "wrong" from an architectural point of view anymore, imo.

+1 Dan _______________________________________________ users mailing list users(a)xwiki.org http://lists.xwiki.org/mailman/listinfo/users

Hi devs, Currently the image plugin [1] allows us to create image thumbnails by specifying the image width and/or height in the query string of the image attachment download URL: /xwiki/bin/download/Spage/Page/image.jpg?width=100 I propose that we: (A) Use the image width and/or height (when they are specified in the image syntax using pixel unit) to resize the image on the server side. For instance: [[image:logo.jpg||width="100px"]] will be linked to /xwiki/bin/download/Spage/Page/logo.jpg?width=100 and [[image:logo.jpg||style="height: 50px; width: 70px"]] will be linked to /xwiki/bin/download/Spage/Page/logo.jpg?width=70&height=50

The image plugin also accepts a quality parameter that controls the compression quality when encoding jpeg images. The default value of this parameter (i.e. when not specified in the URL) is configurable. I propose we use 0.3 by default, 1 representing the best quality.

(B) Add the ability to limit the image dimensions (preserving aspect ratio) when the image width and/or height are not specified in the image syntax (or when they are not using pixel unit). The width and height limit will be configurable and -1 by default (i.e. no limitation). For instance: image:logo.jpg will be linked to /xwiki/bin/download/Spage/Page/logo.jpg?width=1024 when width limit is 1024, and to /xwiki/bin/download/Spage/Page/logo.jpg?width=1024&height=768&keepAspectRatio=true when width limit is 1024 and height limit is 768. Note that in this case the image aspect ratio is preserved. The image is resized to best fit the limits. If the user want to bypass the limit he has to specify the image width/height in the image syntax.

I'm +1 for both (A) and (B). WDYT? Thanks, Marius [1] http://svn.xwiki.org/svnroot/xwiki/platform/core/trunk/xwiki-core/src/main/…

Hi Sergiu, On 09/21/2010 08:27 PM, Sergiu Dumitriu wrote: The default compression quality is configurable. The question is what do we favor by default: performance or quality?

Either you set the width/height limit to -1 or to a reasonable large number in the configuration or you specify the original image width/height in the image wiki syntax. Alternatively you can create a link to the original image with: [[image:logo.jpg>>attach:logo.jpg]]

Note that image width/height limit are -1 by default in the standard XE distribution. Their purpose it to limit image width/height in wikis where users upload large images that can't be display in their full size on a web page (e.g. 3648 x 2736 px). In this case a link to the original image is enough. Thanks for the feedback, Marius