From 34578099c13ec407d3047872a80d1141febf93c9 Mon Sep 17 00:00:00 2001 From: Marcin Rudowski Date: Sat, 6 Mar 2010 11:13:44 +0000 Subject: [PATCH] merged r1661: fixed png256 for large images + improvements to palette generation: #522 --- CHANGELOG | 2 ++ include/mapnik/octree.hpp | 69 +++++++++++++++++++++++++++------------ include/mapnik/png_io.hpp | 10 ++++-- 3 files changed, 57 insertions(+), 24 deletions(-) diff --git a/CHANGELOG b/CHANGELOG index 8775f6908..80576fd10 100644 --- a/CHANGELOG +++ b/CHANGELOG @@ -25,6 +25,8 @@ Mapnik Trunk - Rasterlite Plugin: Experimental support for Rasterlite, to practically use sqlite database with wavelet compressed rasters (#469) +- PNG: fixed png256 for large images and some improvements to reduce color corruptions (#522) + Mapnik 0.7.0 Release -------------------- diff --git a/include/mapnik/octree.hpp b/include/mapnik/octree.hpp index 632ea84fb..38b877fc3 100644 --- a/include/mapnik/octree.hpp +++ b/include/mapnik/octree.hpp @@ -50,7 +50,7 @@ namespace mapnik { struct RGBPolicy { const static unsigned MAX_LEVELS = 6; - const static unsigned MIN_LEVELS = 3; + const static unsigned MIN_LEVELS = 2; inline static unsigned index_from_level(unsigned level, rgb const& c) { unsigned shift = 7 - level; @@ -70,7 +70,7 @@ namespace mapnik { greens(0), blues(0), count(0), - count2(0), + count_cum(0), children_count(0), index(0) { @@ -86,11 +86,12 @@ namespace mapnik { bool is_leaf() const { return count == 0; } node * children_[8]; - unsigned reds; - unsigned greens; - unsigned blues; + boost::uint64_t reds; + boost::uint64_t greens; + boost::uint64_t blues; unsigned count; - unsigned count2; + double reduce_cost; + unsigned count_cum; byte children_count; byte index; }; @@ -98,7 +99,7 @@ namespace mapnik { { bool operator() ( const node * lhs,const node* rhs) const { - return lhs->count2 < rhs->count2; + return lhs->reduce_cost < rhs->reduce_cost; } }; @@ -151,13 +152,13 @@ namespace mapnik { unsigned level = 0; node * cur_node = root_; while (true) { - cur_node->count2++; + cur_node->count_cum++; + cur_node->reds += data.r; + cur_node->greens += data.g; + cur_node->blues += data.b; if ( cur_node->count > 0 || level == leaf_level_) { - cur_node->reds += data.r; - cur_node->greens += data.g; - cur_node->blues += data.b; cur_node->count += 1; if (cur_node->count == 1) ++colors_; //if (colors_ >= max_colors_ - 1) @@ -185,7 +186,8 @@ namespace mapnik { node * cur_node = root_; while (cur_node) { - if (cur_node->count != 0) return cur_node->index + offset_; + if (cur_node->children_count == 0) + return cur_node->index + offset_; unsigned idx = InsertPolicy::index_from_level(level,c); cur_node = cur_node->children_[idx]; ++level; @@ -204,17 +206,44 @@ namespace mapnik { palette.reserve(colors_); create_palette(palette, root_); } + + void computeCost(node *r) + { + r->reduce_cost = 0; + if (r->children_count==0) + return; + + double sum[] = {0,0,0}; + for (unsigned idx=0; idx < 8; ++idx) if (r->children_[idx] != 0) + { + computeCost(r->children_[idx]); + sum[0] += r->children_[idx]->reds; + sum[1] += r->children_[idx]->greens; + sum[2] += r->children_[idx]->blues; + } + + for (unsigned idx=0; idx < 8; ++idx) if (r->children_[idx] != 0) + { + r->reduce_cost += r->children_[idx]->reduce_cost; + r->reduce_cost += fabs(r->children_[idx]->reds + - sum[0] * r->children_[idx]->count_cum / r->count_cum); + r->reduce_cost += fabs(r->children_[idx]->greens + - sum[1] * r->children_[idx]->count_cum / r->count_cum); + r->reduce_cost += fabs(r->children_[idx]->blues + - sum[2] * r->children_[idx]->count_cum / r->count_cum); + } + } void reduce() { + computeCost(root_); reducible_[0].push_back(root_); - // sort reducible + // sort reducible by reduce_cost for (unsigned i=0;i max_colors_ && colors_ > 1) { while (leaf_level_ >0 && reducible_[leaf_level_-1].size() == 0) @@ -226,7 +255,7 @@ namespace mapnik { // select best of all reducible: unsigned red_idx = leaf_level_-1; - unsigned bestv = (*reducible_[red_idx].begin())->count2; + unsigned bestv = (*reducible_[red_idx].begin())->count_cum; for(unsigned i=red_idx; i>=InsertPolicy::MIN_LEVELS; i--) if (!reducible_[i].empty()){ node *nd = *reducible_[i].begin(); unsigned gch = 0; @@ -234,8 +263,8 @@ namespace mapnik { if (nd->children_[idx]) gch += nd->children_[idx]->children_count; } - if (gch==0 && nd->count2count2; + if (gch==0 && nd->count_cumcount_cum; red_idx = i; } } @@ -249,10 +278,8 @@ namespace mapnik { { cur_node->children_count--; ++num_children; - cur_node->reds += cur_node->children_[idx]->reds; - cur_node->greens += cur_node->children_[idx]->greens; - cur_node->blues += cur_node->children_[idx]->blues; cur_node->count += cur_node->children_[idx]->count; + //todo: case of nonleaf children, if someday sorting by reduce_cost doesn't handle it delete cur_node->children_[idx], cur_node->children_[idx]=0; } } @@ -273,7 +300,7 @@ namespace mapnik { palette.push_back(rgb(byte(itr->reds/float(count)), byte(itr->greens/float(count)), byte(itr->blues/float(count)))); - itr->index = palette.size() - 1; + itr->index = palette.size() - 1; } for (unsigned i=0; i < 8 ;++i) { diff --git a/include/mapnik/png_io.hpp b/include/mapnik/png_io.hpp index 1278f209c..9e6cdb01a 100644 --- a/include/mapnik/png_io.hpp +++ b/include/mapnik/png_io.hpp @@ -332,12 +332,16 @@ namespace mapnik { unsigned divCoef = width*height-cols[0]; if (divCoef==0) divCoef = 1; cols[0] = cols[0]>0?1:0; // fully transparent color (one or not at all) + + // give chance less populated but not empty cols to have at least few colors(12) + unsigned minCols = (12+1)*divCoef/(256-cols[0]); + for(int j=1; j12 && cols[j]12 && cols[j]<12) - cols[j] = 12; // reserve at least 12 colors to have any effect usedColors += cols[j]; } // use rest for most opaque group of pixels