I'm trying to export image data from blender. Getting width, height and size works fine but something is wrong when I write the pixels to file.

This is the image I have loaded in blender: http://localhostr.com/files/6WHyRnC/Crate.jpg
this is how it looks in my game engine when I load it: http://localhostr.com/files/l4oWGWF/Untitled.png

I know I can just load the texture file from my game but I want to have the images packed inside the model file along with the vertices, normals etc...

This is how I export the image data from blender, am I doing something completely wrong here?

Code:

# Write number of images WriteInt(File, len(bpy.data.images)) for i, Image in enumerate(bpy.data.images):     # Write width     WriteInt(File, Image.size[0])         # Write height     WriteInt(File, Image.size[1])         # Write size     WriteInt(File, len(Image.pixels))         # Write pixels     Pixels = array('f', Image.pixels)     Pixels.tofile(File)

If you are writing PNGs, they have a header and a bunch of chunks, not just a linear stream of pixels.

I'm not writing as a image file so I don't need the header. I want the raw pixels only.

looks like the byte order is messed up...

i've done this to export to bmp:

Code:

import bpy import struct def hx(float_color):     return int(float_color * 255) with open("D:\\imgg.bmp", "wb") as f:     i = bpy.data.images[0]     p = i.pixels     w, h = i.size         f.write(bytearray("BM", 'ASCII'))     f.write(struct.pack("iiiiiihhiiiiii",                         (54+len(p)*3), 0, 54, 40, w, h, 1, 24, 0, 0, 0, 0,                         0, 0 ))     c = 0     for i in range(len(p)//4):         f.write(struct.pack("BBB", hx(p[c+2]), hx(p[c+1]), hx(p[c])))         c += 4

as you see, i need to process the values (float to int, different order)

i had similar stripes like you in my first attempt, 'cause Blender's Image.pixels are stored like

RGBA RGBA RGBA ...

but the output format was bitmap 24bpp, which is like:
BGR BGR BGR ...

see the mismatch:

Code:

BGR BGR BGR BGR RGB ARG BAR GBA

so you may have to pick the proper data type (e.g. 32bpp) or process the input before outputting
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I'm sitting, waiting, wishing, building Blender in superstition...

Interesting topic. Anyway, I tried your code and it works.

But srsly.... but it's just slow. And with slow I mean it's freaking mighty slow.

Why is that?

CoDEmanX wrote:

looks like the byte order is messed up... i've done this to export to bmp: Code: import bpy import struct def hx(float_color):     return int(float_color * 255) with open("D:\\imgg.bmp", "wb") as f:     i = bpy.data.images[0]     p = i.pixels     w, h = i.size         f.write(bytearray("BM", 'ASCII'))     f.write(struct.pack("iiiiiihhiiiiii",                         (54+len(p)*3), 0, 54, 40, w, h, 1, 24, 0, 0, 0, 0,                         0, 0 ))     c = 0     for i in range(len(p)//4):         f.write(struct.pack("BBB", hx(p[c+2]), hx(p[c+1]), hx(p[c])))         c += 4         as you see, i need to process the values (float to int, different order) i had similar stripes like you in my first attempt, 'cause Blender's Image.pixels are stored like RGBA RGBA RGBA ... but the output format was bitmap 24bpp, which is like: BGR BGR BGR ... see the mismatch: Code: BGR BGR BGR BGR RGB ARG BAR GBA so you may have to pick the proper data type (e.g. 32bpp) or process the input before outputting

Thanks, it works! To bad though that it's so slow :/

it's not optimized, could be improved i bet

however, i rather switched to TGA format, as it officially supports alpha (RGBA)

did some speed tests and came up with this:

Code:

import bpy import struct, time def write_tga(image_index, filepath):         with open(filepath, "wb") as f:             try:             img = bpy.data.images[image_index]         except IndexError:             print("Error: bpy.data.images[%i] does not exist!" % image_index)             return                 w, h = img.size                 f.write(struct.pack("<HBIIBHHBB", 0, 2, 0, 0, 0, w, h, 32, 8))         f.write(bytes([int(pix*255) for pix in img.pixels]))         f.close() filepath = "D:\\imgg.tga" t = time.clock() write_tga(0, filepath) print("Time: %.2f" % (time.clock() - t))

with comments (incl. other methods i tried out):
http://www.pasteall.org/33208/python

struct.pack byte for byte was really slow, all others varying between 6.4 and 7.5 seconds

the one i finally put takes 6.1 - 6.5, for a 1024*1024 pixel image
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I'm sitting, waiting, wishing, building Blender in superstition...

Thanks works perfect now!

Woah it's fast now.

Can you make it so Red channel is swapped with Blue? I mean convert RGBA -> BGRA.

Ok, to answer my own question: need to convert bytearray instead and then it's free to manipulate in any way to wish.