Revision: 6318
http://matplotlib.svn.sourceforge.net/matplotlib/?rev=6318&view=rev
Author: mdboom
Date: 2008-10-24 14:05:07 +0000 (Fri, 24 Oct 2008)
Log Message:
-----------
Support reading low-bit depth (< 8) PNG images. Add PNG test suite to make
sure we're supporting the basic kinds of PNG files available.
Modified Paths:
--------------
trunk/matplotlib/src/_png.cpp
Added Paths:
-----------
trunk/matplotlib/examples/tests/pngsuite/
trunk/matplotlib/examples/tests/pngsuite/basn0g01.png
trunk/matplotlib/examples/tests/pngsuite/basn0g02.png
trunk/matplotlib/examples/tests/pngsuite/basn0g04.png
trunk/matplotlib/examples/tests/pngsuite/basn0g08.png
trunk/matplotlib/examples/tests/pngsuite/basn0g16.png
trunk/matplotlib/examples/tests/pngsuite/basn2c08.png
trunk/matplotlib/examples/tests/pngsuite/basn2c16.png
trunk/matplotlib/examples/tests/pngsuite/basn3p01.png
trunk/matplotlib/examples/tests/pngsuite/basn3p02.png
trunk/matplotlib/examples/tests/pngsuite/basn3p04.png
trunk/matplotlib/examples/tests/pngsuite/basn3p08.png
trunk/matplotlib/examples/tests/pngsuite/basn4a08.png
trunk/matplotlib/examples/tests/pngsuite/basn4a16.png
trunk/matplotlib/examples/tests/pngsuite/basn6a08.png
trunk/matplotlib/examples/tests/pngsuite/basn6a16.png
trunk/matplotlib/examples/tests/pngsuite/pngsuite.py
trunk/matplotlib/examples/tests/pngsuite/truth.png
Added: trunk/matplotlib/examples/tests/pngsuite/basn0g01.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn0g01.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn0g02.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn0g02.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn0g04.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn0g04.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn0g08.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn0g08.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn0g16.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn0g16.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn2c08.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn2c08.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn2c16.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn2c16.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn3p01.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn3p01.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn3p02.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn3p02.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn3p04.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn3p04.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn3p08.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn3p08.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn4a08.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn4a08.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn4a16.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn4a16.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn6a08.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn6a08.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/basn6a16.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/basn6a16.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Added: trunk/matplotlib/examples/tests/pngsuite/pngsuite.py
===================================================================
--- trunk/matplotlib/examples/tests/pngsuite/pngsuite.py
(rev 0)
+++ trunk/matplotlib/examples/tests/pngsuite/pngsuite.py 2008-10-24
14:05:07 UTC (rev 6318)
@@ -0,0 +1,24 @@
+"""
+This test loads a subset of the files in Willem van Schaik's PNG test
+suite available here:
+
+ http://libpng.org/pub/png/pngsuite.html
+
+The result should look like truth.png.
+"""
+
+from matplotlib import pyplot as plt
+import glob
+
+files = glob.glob("basn*.png")
+files.sort()
+
+plt.figure(figsize=(len(files), 2))
+
+for i, fname in enumerate(files):
+ data = plt.imread(fname)
+ plt.imshow(data, extent=[i,i+1,0,1])
+
+plt.gca().get_frame().set_facecolor("#ddffff")
+plt.gca().set_xlim(0, len(files))
+plt.show()
Added: trunk/matplotlib/examples/tests/pngsuite/truth.png
===================================================================
(Binary files differ)
Property changes on: trunk/matplotlib/examples/tests/pngsuite/truth.png
___________________________________________________________________
Added: svn:mime-type
+ application/octet-stream
Modified: trunk/matplotlib/src/_png.cpp
===================================================================
--- trunk/matplotlib/src/_png.cpp 2008-10-24 11:43:31 UTC (rev 6317)
+++ trunk/matplotlib/src/_png.cpp 2008-10-24 14:05:07 UTC (rev 6318)
@@ -213,19 +213,25 @@
png_uint_32 width = info_ptr->width;
png_uint_32 height = info_ptr->height;
+ bool do_gray_conversion = (info_ptr->bit_depth < 8 &&
+ info_ptr->color_type == PNG_COLOR_TYPE_GRAY);
+ int bit_depth = info_ptr->bit_depth;
+ if (bit_depth == 16) {
+ png_set_strip_16(png_ptr);
+ } else if (bit_depth < 8) {
+ png_set_packing(png_ptr);
+ } else {
+ }
+
// convert misc color types to rgb for simplicity
if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY ||
- info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
png_set_gray_to_rgb(png_ptr);
- else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ } else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) {
png_set_palette_to_rgb(png_ptr);
+ }
-
- int bit_depth = info_ptr->bit_depth;
- if (bit_depth == 16) png_set_strip_16(png_ptr);
-
-
png_set_interlace_handling(png_ptr);
png_read_update_info(png_ptr, info_ptr);
@@ -247,8 +253,6 @@
png_read_image(png_ptr, row_pointers);
-
-
npy_intp dimensions[3];
dimensions[0] = height; //numrows
dimensions[1] = width; //numcols
@@ -256,19 +260,31 @@
PyArrayObject *A = (PyArrayObject *) PyArray_SimpleNew(3, dimensions,
PyArray_FLOAT);
-
- for (png_uint_32 y = 0; y < height; y++) {
- png_byte* row = row_pointers[y];
- for (png_uint_32 x = 0; x < width; x++) {
-
- png_byte* ptr = (rgba) ? &(row[x*4]) : &(row[x*3]);
- size_t offset = y*A->strides[0] + x*A->strides[1];
- //if ((y<10)&&(x==10)) std::cout << "r = " << ptr[0] << " " <<
ptr[0]/255.0 << std::endl;
- *(float*)(A->data + offset + 0*A->strides[2]) = (float)(ptr[0]/255.0f);
- *(float*)(A->data + offset + 1*A->strides[2]) = (float)(ptr[1]/255.0f);
- *(float*)(A->data + offset + 2*A->strides[2]) = (float)(ptr[2]/255.0f);
- *(float*)(A->data + offset + 3*A->strides[2]) = rgba ?
(float)(ptr[3]/255.0f) : 1.0f;
+ if (do_gray_conversion) {
+ float max_value = (float)((1L << bit_depth) - 1);
+ for (png_uint_32 y = 0; y < height; y++) {
+ png_byte* row = row_pointers[y];
+ for (png_uint_32 x = 0; x < width; x++) {
+ float value = row[x] / max_value;
+ size_t offset = y*A->strides[0] + x*A->strides[1];
+ *(float*)(A->data + offset + 0*A->strides[2]) = value;
+ *(float*)(A->data + offset + 1*A->strides[2]) = value;
+ *(float*)(A->data + offset + 2*A->strides[2]) = value;
+ *(float*)(A->data + offset + 3*A->strides[2]) = 1.0f;
+ }
}
+ } else {
+ for (png_uint_32 y = 0; y < height; y++) {
+ png_byte* row = row_pointers[y];
+ for (png_uint_32 x = 0; x < width; x++) {
+ png_byte* ptr = (rgba) ? &(row[x*4]) : &(row[x*3]);
+ size_t offset = y*A->strides[0] + x*A->strides[1];
+ *(float*)(A->data + offset + 0*A->strides[2]) = (float)(ptr[0]/255.0);
+ *(float*)(A->data + offset + 1*A->strides[2]) = (float)(ptr[1]/255.0);
+ *(float*)(A->data + offset + 2*A->strides[2]) = (float)(ptr[2]/255.0);
+ *(float*)(A->data + offset + 3*A->strides[2]) = rgba ?
(float)(ptr[3]/255.0) : 1.0f;
+ }
+ }
}
//free the png memory
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