<html>
  <head>
    <meta content="text/html; charset=ISO-8859-1"
      http-equiv="Content-Type">
  </head>
  <body bgcolor="#FFFFFF" text="#000000">
    <div class="moz-cite-prefix">C'est bon, mod_tile était compilé en
      'png256'. Ca marche nickel maintenant.<br>
      <br>
      On 01/12/2014 03:28 PM, Christian Quest wrote:<br>
    </div>
    <blockquote
cite="mid:CAAXY6DMOZLK4ejx-rCWOe7c-HnHOF50xJ8nMk4P1JV+UBaQmpg@mail.gmail.com"
      type="cite">
      <div dir="ltr">J'ai bien compris que Mapnik merdouillait en
        faisant une sorte de solarisation.
        <div><br>
        </div>
        <div>Ma remarque porte sur un autre problème potentiel, le choix
          de rampe qui va produire des effets qui ne sont pas exactement
          ceux que tu veux mais qui ne sont pas à l'origine du défaut
          que tu signale.</div>
      </div>
      <div class="gmail_extra"><br>
        <br>
        <div class="gmail_quote">Le 12 janvier 2014 15:13, yvecai <span
            dir="ltr"><<a moz-do-not-send="true"
              href="mailto:yvecai@gmail.com" target="_blank">yvecai@gmail.com</a>></span>
          a écrit :<br>
          <blockquote class="gmail_quote" style="margin:0 0 0
            .8ex;border-left:1px #ccc solid;padding-left:1ex">
            <div bgcolor="#FFFFFF" text="#000000">
              <div>Non, tu n'y est pas: je suis content de l'effet
                d'ombre. Dans mon cas, je ne fais que traduire une bande
                en niveau de gris en une bande en niveaux d'alpha.<br>
                <br>
                C'est le rendu Mapnik qui me chagrine.
                <div>
                  <div class="h5"><br>
                    <br>
                    On 01/12/2014 01:27 PM, Christian Quest wrote:<br>
                  </div>
                </div>
              </div>
              <div>
                <div class="h5">
                  <blockquote type="cite">
                    <div dir="ltr">Si tu veux garder uniquement les
                      ombres, j'utiliserai cette rampe:
                      <div><br>
                      </div>
                      <div>0 0 0 0 255</div>
                      <div>128 0 0 0 0</div>
                      <div>255 0 0 0 0</div>
                      <div><br>
                      </div>
                      <div>Tout est noir, et l'opacité décroit jusqu'au
                        milieu, puis reste nulle pour les zones
                        ensoleillées.</div>
                      <div><br>
                      </div>
                    </div>
                    <div class="gmail_extra"><br>
                      <br>
                      <div class="gmail_quote">Le 12 janvier 2014 12:56,
                        yvecai <span dir="ltr"><<a
                            moz-do-not-send="true"
                            href="mailto:yvecai@gmail.com"
                            target="_blank">yvecai@gmail.com</a>></span>
                        a écrit :<br>
                        <blockquote class="gmail_quote" style="margin:0
                          0 0 .8ex;border-left:1px #ccc
                          solid;padding-left:1ex">
                          <div bgcolor="#FFFFFF" text="#000000">
                            <div>La suite sur DEV ...<br>
                              <br>
                              Comme j'ai déjà un tif en niveau de gris
                              qui me convient, j'ai juste:<br>
                              0 0 0 0 254<br>
                              254 0 0 0 0<br>
                              Je ne souhaite pas éclaircir le coté
                              ensoleillé, juste assombrir coté ombres.<br>
                              <br>
                              Voici un bout de fichier converti en
                              transparent autour du Leman: <a
                                moz-do-not-send="true"
                                href="http://www3.opensnowmap.org/download/3857-cropped-alpha.tif"
                                target="_blank">http://www3.opensnowmap.org/download/3857-cropped-alpha.tif</a><br>
                              <br>
                              Je pense que mon problème vient plus de
                              mapnik, car le fichier est correct dans
                              Qgis<span><font color="#888888"><br>
                                  Yves</font></span>
                              <div>
                                <div><br>
                                  <br>
                                  On 01/12/2014 12:32 PM, Christian
                                  Quest wrote:<br>
                                </div>
                              </div>
                            </div>
                            <div>
                              <div>
                                <blockquote type="cite">
                                  <div dir="ltr">A quoi ressemble ton
                                    fichier "ramp" utilisé par le
                                    color-relief ?
                                    <div><br>
                                    </div>
                                    <div>C'est lui qui va faire le
                                      mapping niveau de gris ->
                                      noir/blanc+alpha</div>
                                    <div><br>
                                    </div>
                                    <div>Je l'ai simplifié pour obtenir
                                      un résultat plus progressif par
                                      rapport à mes premiers essais, ma
                                      version actuelle se résume à 4
                                      lignes:</div>
                                    <div>
                                      <div>0 0 0 0 255</div>
                                      <div>128 0 0 0 0</div>
                                      <div>129 255 255 255 0</div>
                                      <div>255 255 255 255 192</div>
                                    </div>
                                    <div><br>
                                    </div>
                                    <div>de 0 à 128 c'est une ombre,
                                      donc du noir avec un alpha
                                      décroissant (de 100% à 0%)</div>
                                    <div>de 129 à 255 c'est un côté au
                                      soleil, que j'éclaircit mais plus
                                      légèrement avec un blanc et un
                                      alpha croissant (de 0% à 75%)</div>
                                    <div><br>
                                    </div>
                                    <div>J'ai fait des essais sur de
                                      petites zones en regardant les
                                      valeurs avec quelques clics d'info
                                      dans l'image sous QGis.</div>
                                    <div><br>
                                    </div>
                                  </div>
                                  <div class="gmail_extra"><br>
                                    <br>
                                    <div class="gmail_quote">Le 12
                                      janvier 2014 11:12, yvecai <span
                                        dir="ltr"><<a
                                          moz-do-not-send="true"
                                          href="mailto:yvecai@gmail.com"
                                          target="_blank">yvecai@gmail.com</a>></span>
                                      a écrit :<br>
                                      <blockquote class="gmail_quote"
                                        style="margin:0 0 0
                                        .8ex;border-left:1px #ccc
                                        solid;padding-left:1ex">
                                        <div>On 12/30/2013 01:41 PM,
                                          Christian Quest wrote:<br>
                                          <blockquote
                                            class="gmail_quote"
                                            style="margin:0 0 0
                                            .8ex;border-left:1px #ccc
                                            solid;padding-left:1ex">
                                            Exit le script python ou les
                                            comp-op dans mapnik (autre
                                            solution proposée sur le
                                            blog de mapbox).<br>
                                          </blockquote>
                                          <br>
                                        </div>
                                        Salut Christian,<br>
                                        <br>
                                        Du coup, j'essaie ta méthode
                                        avec gdaldem color-relief pour
                                        balancer un hillshade qui ne
                                        soit pas trop lourd dans Mapnik.<br>
                                        J'obtiens bien un tiff tout noir
                                        avec un alpha-channel qui varie
                                        et qui sort bien sur un
                                        visualiseur d'image. Juste
                                        gdaldem est super long sur un
                                        tif de 100GB, mais bon.<br>
                                        Mon soucis c'est que mais mapnik
                                        2.2.0 fait comme si le canal
                                        alpha étant codé sur 2 bits
                                        (j'ai 3-4 nuances seulement).<br>
                                        Tu es sur quelle version de
                                        mapnik?<br>
                                        On peut comparer nos styles ?<br>
                                        <br>
                                        <Style name="hillshade"><br>
                                          <Rule><br>
                                            &maxscale_zoom8;<br>
                                            &minscale_zoom11;<br>
                                            <RasterSymbolizer
                                        opacity="1"/><br>
                                          </Rule><br>
                                        </Style><br>
                                        <Layer name="hillshade12"<br>
                                          srs="+proj=merc +a=6378137
                                        +b=6378137 +lat_ts=0.0
                                        +lon_0=0.0 +x_0=0.0 +y_0=0.0
                                        +k=1.0 +units=m +nadgrids=@null
                                        +wktext +no_defs +over"><br>
                                           
                                        <StyleName>hillshade12</StyleName><br>
                                            <Datasource><br>
                                               <Parameter
                                        name="file">/home/admin/DEM/3857-cropped-alpha.tif</Parameter><br>
                                               <Parameter
                                        name="type">gdal</Parameter><br>
                                            </Datasource><br>
                                          </Layer><br>
                                        <br>
                                        gdalinfo 3857-cropped-alpha.tif<br>
                                        ...<br>
                                        Band 1 Block=256x256 Type=Byte,
                                        ColorInterp=Red<br>
                                          Min=0.000 Max=0.000<br>
                                          Minimum=0.000, Maximum=0.000,
                                        Mean=0.000, StdDev=0.000<br>
                                          Mask Flags: PER_DATASET ALPHA<br>
                                          Metadata:<br>
                                            STATISTICS_MAXIMUM=0<br>
                                            STATISTICS_MEAN=0<br>
                                            STATISTICS_MINIMUM=0<br>
                                            STATISTICS_STDDEV=0<br>
                                        Band 2 Block=256x256 Type=Byte,
                                        ColorInterp=Green<br>
                                          Min=0.000 Max=0.000<br>
                                          Minimum=0.000, Maximum=0.000,
                                        Mean=0.000, StdDev=0.000<br>
                                          Mask Flags: PER_DATASET ALPHA<br>
                                          Metadata:<br>
                                            STATISTICS_MAXIMUM=0<br>
                                            STATISTICS_MEAN=0<br>
                                            STATISTICS_MINIMUM=0<br>
                                            STATISTICS_STDDEV=0<br>
                                        Band 3 Block=256x256 Type=Byte,
                                        ColorInterp=Blue<br>
                                          Min=0.000 Max=0.000<br>
                                          Minimum=0.000, Maximum=0.000,
                                        Mean=0.000, StdDev=0.000<br>
                                          Mask Flags: PER_DATASET ALPHA<br>
                                          Metadata:<br>
                                            STATISTICS_MAXIMUM=0<br>
                                            STATISTICS_MEAN=0<br>
                                            STATISTICS_MINIMUM=0<br>
                                            STATISTICS_STDDEV=0<br>
                                        Band 4 Block=256x256 Type=Byte,
                                        ColorInterp=Alpha<br>
                                          Min=0.000 Max=254.000<br>
                                          Minimum=0.000,
                                        Maximum=254.000, Mean=79.883,
                                        StdDev=96.858<br>
                                          Metadata:<br>
                                            STATISTICS_MAXIMUM=254<br>
                                           
                                        STATISTICS_MEAN=79.882783050415<br>
                                            STATISTICS_MINIMUM=0<br>
                                           
                                        STATISTICS_STDDEV=96.857864812661<br>
                                        <br>
                                        <br>
_______________________________________________<br>
                                        dev-fr mailing list<br>
                                        <a moz-do-not-send="true"
                                          href="mailto:dev-fr@openstreetmap.org"
                                          target="_blank">dev-fr@openstreetmap.org</a><br>
                                        <a moz-do-not-send="true"
                                          href="https://lists.openstreetmap.org/listinfo/dev-fr"
                                          target="_blank">https://lists.openstreetmap.org/listinfo/dev-fr</a><br>
                                        <br>
                                      </blockquote>
                                    </div>
                                    <br>
                                    <br clear="all">
                                    <div><br>
                                    </div>
                                    -- <br>
                                    <div dir="ltr">Christian Quest -
                                      OpenStreetMap France</div>
                                  </div>
                                  <br>
                                  <fieldset></fieldset>
                                  <br>
                                  <pre>_______________________________________________
dev-fr mailing list
<a moz-do-not-send="true" href="mailto:dev-fr@openstreetmap.org" target="_blank">dev-fr@openstreetmap.org</a>
<a moz-do-not-send="true" href="https://lists.openstreetmap.org/listinfo/dev-fr" target="_blank">https://lists.openstreetmap.org/listinfo/dev-fr</a>
</pre>
                                </blockquote>
                                <br>
                              </div>
                            </div>
                          </div>
                          <br>
_______________________________________________<br>
                          dev-fr mailing list<br>
                          <a moz-do-not-send="true"
                            href="mailto:dev-fr@openstreetmap.org"
                            target="_blank">dev-fr@openstreetmap.org</a><br>
                          <a moz-do-not-send="true"
                            href="https://lists.openstreetmap.org/listinfo/dev-fr"
                            target="_blank">https://lists.openstreetmap.org/listinfo/dev-fr</a><br>
                          <br>
                        </blockquote>
                      </div>
                      <br>
                      <br clear="all">
                      <div><br>
                      </div>
                      -- <br>
                      <div dir="ltr">Christian Quest - OpenStreetMap
                        France</div>
                    </div>
                    <br>
                    <fieldset></fieldset>
                    <br>
                    <pre>_______________________________________________
dev-fr mailing list
<a moz-do-not-send="true" href="mailto:dev-fr@openstreetmap.org" target="_blank">dev-fr@openstreetmap.org</a>
<a moz-do-not-send="true" href="https://lists.openstreetmap.org/listinfo/dev-fr" target="_blank">https://lists.openstreetmap.org/listinfo/dev-fr</a>
</pre>
                  </blockquote>
                  <br>
                </div>
              </div>
            </div>
            <br>
            _______________________________________________<br>
            dev-fr mailing list<br>
            <a moz-do-not-send="true"
              href="mailto:dev-fr@openstreetmap.org">dev-fr@openstreetmap.org</a><br>
            <a moz-do-not-send="true"
              href="https://lists.openstreetmap.org/listinfo/dev-fr"
              target="_blank">https://lists.openstreetmap.org/listinfo/dev-fr</a><br>
            <br>
          </blockquote>
        </div>
        <br>
        <br clear="all">
        <div><br>
        </div>
        -- <br>
        <div dir="ltr">Christian Quest - OpenStreetMap France</div>
      </div>
      <br>
      <fieldset class="mimeAttachmentHeader"></fieldset>
      <br>
      <pre wrap="">_______________________________________________
dev-fr mailing list
<a class="moz-txt-link-abbreviated" href="mailto:dev-fr@openstreetmap.org">dev-fr@openstreetmap.org</a>
<a class="moz-txt-link-freetext" href="https://lists.openstreetmap.org/listinfo/dev-fr">https://lists.openstreetmap.org/listinfo/dev-fr</a>
</pre>
    </blockquote>
    <br>
  </body>
</html>