From: Pearce Pearce on 28 Mar 2010 12:02 Hey guys! I have an univercity exersise: I'm trying to get YUV channels from BMP picture, and output it like 3 grey images. I know the proportion: RGB to YUV Y = (0.257 * R) + (0.504 * G) + (0.098 * B) + 16 V = (0.439 * R) - (0.368 * G) - (0.071 * B) + 128 U = -(0.148 * R) - (0.291 * G) + (0.439 * B) + 128 But don't know how to get it works with Ruby. Thanks in advance! -- Posted via http://www.ruby-forum.com/. From: Markus Schirp on 28 Mar 2010 13:56 Hello, I dont think the ruby-ml, or the ruby-forums, are an exersise solving machine... But i can give you the following overall picture of your programm (more pseudocode than ruby) ==== BEGIN image = open_source_image y_image = open_new_image u_image = open_new_image v_image = open_new_image for pixel_in_image in image do y,u,v = calculate_yuv_for_pixel(pixel) write_to_image(y_image,y) write_to_image(u_image,u) write_to_image(v_image,v) end ==== END greetings, Markus On Mon, Mar 29, 2010 at 01:02:25AM +0900, Pearce Pearce wrote:> Hey guys! > I have an univercity exersise: > I'm trying to get YUV channels from BMP picture, and output it like 3 > grey images. > I know the proportion: > RGB to YUV > Y = (0.257 * R) + (0.504 * G) + (0.098 * B) + 16 > V = (0.439 * R) - (0.368 * G) - (0.071 * B) + 128 > U = -(0.148 * R) - (0.291 * G) + (0.439 * B) + 128 > > But don't know how to get it works with Ruby. > > Thanks in advance! > -- > Posted via http://www.ruby-forum.com/. From: Markus Schirp on 28 Mar 2010 14:01 Hola again, Im reposting the pseudocode, since the first one leads to uninitialized local variable 'pixel', renamed it to 'pixel_in_image' image = open_source_image y_image = open_new_image u_image = open_new_image v_image = open_new_image for pixel_in_image in image do y,u,v = calculate_yuv_for_pixel(pixel_in_image) write_to_image(y_image,y) write_to_image(u_image,u) write_to_image(v_image,v) end On Mon, Mar 29, 2010 at 02:56:18AM +0900, Markus Schirp wrote:> Hello, > > I dont think the ruby-ml, or the ruby-forums, are an exersise solving > machine... > > But i can give you the following overall picture of your programm > (more pseudocode than ruby) > > ==== BEGIN > > image = open_source_image > > y_image = open_new_image > u_image = open_new_image > v_image = open_new_image > > for pixel_in_image in image do > y,u,v = calculate_yuv_for_pixel(pixel) > write_to_image(y_image,y) > write_to_image(u_image,u) > write_to_image(v_image,v) > end > > ==== END > > greetings, > > Markus > > On Mon, Mar 29, 2010 at 01:02:25AM +0900, Pearce Pearce wrote: > > Hey guys! > > I have an univercity exersise: > > I'm trying to get YUV channels from BMP picture, and output it like 3 > > grey images. > > I know the proportion: > > RGB to YUV > > Y = (0.257 * R) + (0.504 * G) + (0.098 * B) + 16 > > V = (0.439 * R) - (0.368 * G) - (0.071 * B) + 128 > > U = -(0.148 * R) - (0.291 * G) + (0.439 * B) + 128 > > > > But don't know how to get it works with Ruby. > > > > Thanks in advance! > > -- > > Posted via http://www.ruby-forum.com/.  |  Pages: 1 Prev: non-blocking calls to external APIsNext: a question about gem's ~>