Search found 15 matches

by davecazz
2012-02-09T00:42:11-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

Actually 'map' actually looks more like a HALD image to me, mathematically generated? yea, I created it in python, just 4 nested for loops iterating through all the possible values of RGBA Hmmm try this... convert uranus.png -channel RGBA -ordered-dither checks,4 +channel uranus_od.png Other thresh...
by davecazz
2012-02-09T00:19:36-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

actually my bad, I didnt see your edit on your message. going to try that out now.
by davecazz
2012-02-09T00:17:36-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

this is the command I sent,

convert uranus.png -quantize transparent -dither None -remap imagepalettergba4444.png RemapUranusNoDither.png

this got rid of the alpha channel.
by davecazz
2012-02-08T22:57:15-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

yea, I will do this as a last resort. there are many textures I have to process during the build phase, so getting it down to a single operation would be first choice.
by davecazz
2012-02-08T22:49:13-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

and I just tried it with -quantize transparent and it removed the alpha channel in the resulting image.
by davecazz
2012-02-08T22:46:31-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

Hey Anthony,

thanks for responding. the question is actually at the start of the post. I'm not doing color quantization. just -remap using a color table image.
by davecazz
2012-02-08T19:39:52-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

and I was just thinking that another way to go about it is to separate the alpha from the RGB channels. dither the alpha channel as if its an 8 bit gray scale image, then apply that to the RGB reduced color image. about the two articles. this one talks about quantization, this applies to determining...
by davecazz
2012-02-08T19:23:29-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

thanks, I'll check that out. for the most part, I can reduce the bit depth of colors in an image with python and PIL pretty easily, its the dithering I'm trying to get use of. even with dithering, the guys at PVRTexTool are planning a build that exposes that to their command line version fairly soon...
by davecazz
2012-02-08T19:12:43-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

sure, thanks for your help
by davecazz
2012-02-08T19:05:33-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

that's exactly right. RGBA8888 means 8 bits red, 8 bits blue, 8 bits green and 8 bits alpha. this is the color format of a typical 32bit color pixel. RGB565 represents a 16bit pixel value with 5 bits red, 6 bits green, 5 bits blue but no alpha. RGBA5551 is also 16 bit but you remove 1 bit from green...
by davecazz
2012-02-08T16:28:50-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

oh yea, and the reason why the image looks like that is because you are just doing a nested for loop for red, green, and blue from 0 to 255. you see a step each time the inner color loops back to 0.
by davecazz
2012-02-08T16:27:17-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

yea, it's very similar in terms of the color image, those images are 3d color lookup tables. R,G and B being the dimensions. my color table would be classified as a 4d table because it adds alpha. the use the the table is a bit different though. with the 3D color mapping on that page, they are looki...
by davecazz
2012-02-08T16:02:43-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

the last two images are remapped with a different tool called PVRTexTool that is meant to create textures optiized for mobile graphic hardware. they are both doing the same operation, or rather I'm trying to do the same operation with ImageMagick. PVRTexTool has an option to just reduce an image fro...
by davecazz
2012-02-08T15:47:18-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

Re: bad alpha in -remap from RGBA8888 to RGBA4444

I can see how you might think that at first glance but there is a problem in the alpha channel. the alpha channel has been reduced improperly. if you load it into a visual image editor, you can see that the original image is pretty much 100% solid alpha in the middle, 0% outside of the graphic, and ...
by davecazz
2012-02-08T15:10:12-07:00
Forum: Users
Topic: bad alpha in -remap from RGBA8888 to RGBA4444
Replies: 27
Views: 44624

bad alpha in -remap from RGBA8888 to RGBA4444

Hello, trying to use image magick to do some 32 to 16 bit color reduction. it seems to be doing some really weird dithering with the alpha channel though. here is the original image http://dev.boltcreative.com/uranus.png I have a RGBA4444 color table image http://dev.boltcreative.com/ImagePaletteRGB...