hi everybody,
in a gray-scale image, how to change the pixels, that are brighter/higher than e.g. rgb(180,180,180) to more red, e.g. rgb(240,140,140) ?
so I want to keep the darker gray pixels e.g. rgb(070,070,070) as is, but for the brighter ones increase red, and/or decrease green and blue
once a certain threshold is reached. given a threshold t, and a given grey pixel rgb(o,o,o), my algorithm may look like:
if (o > t) {r=min(255, o+60); g=o-40; b=o-40; newPix=rgb(r,g,b)}
something similar is probably already implemented (much smarter of course) in the "sepia" function, where you turn gray into color.
which image format would be the easiest ? image size I am looking at, is about 900x600.
I tried already some perl scripting, but got lost/stuck with linking pm-modules and dylibs running on an old G5 Mac OS 10.4.11.
thanks 4 any help and suggestions, wunderer.
convert olny bright gray to color
Moderators: XnTriq, helmut, xnview
Re: convert olny bright gray to color
Hi wunderer
I don't know how to achieve this in XnView, but I've done similar stuff in (old shareware versions of) Paint Shop Pro by converting my image(s) to 256 shades of gray, exporting the color table to PSP's palette format (plain text), editing the values (Excel + Notepad), saving the result back to a PSP palette and applying the colors to my image(s) with the Maintain indexes option enabled.
I don't know how to achieve this in XnView, but I've done similar stuff in (old shareware versions of) Paint Shop Pro by converting my image(s) to 256 shades of gray, exporting the color table to PSP's palette format (plain text), editing the values (Excel + Notepad), saving the result back to a PSP palette and applying the colors to my image(s) with the Maintain indexes option enabled.
Update: As it turns out, XnView is capable of saving & loading palettes in PSP format (Image » Edit Palette...) and maintains the indexes.[color=green]greyscale.pal[/color] wrote:Code: Select all
JASC-PAL 0100 256 0 0 0 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5 6 6 6 7 7 7 8 8 8 9 9 9 10 10 10 11 11 11 12 12 12 13 13 13 14 14 14 15 15 15 16 16 16 17 17 17 18 18 18 19 19 19 20 20 20 21 21 21 22 22 22 23 23 23 24 24 24 25 25 25 26 26 26 27 27 27 28 28 28 29 29 29 30 30 30 31 31 31 32 32 32 33 33 33 34 34 34 35 35 35 36 36 36 37 37 37 38 38 38 39 39 39 40 40 40 41 41 41 42 42 42 43 43 43 44 44 44 45 45 45 46 46 46 47 47 47 48 48 48 49 49 49 50 50 50 51 51 51 52 52 52 53 53 53 54 54 54 55 55 55 56 56 56 57 57 57 58 58 58 59 59 59 60 60 60 61 61 61 62 62 62 63 63 63 64 64 64 65 65 65 66 66 66 67 67 67 68 68 68 69 69 69 70 70 70 71 71 71 72 72 72 73 73 73 74 74 74 75 75 75 76 76 76 77 77 77 78 78 78 79 79 79 80 80 80 81 81 81 82 82 82 83 83 83 84 84 84 85 85 85 86 86 86 87 87 87 88 88 88 89 89 89 90 90 90 91 91 91 92 92 92 93 93 93 94 94 94 95 95 95 96 96 96 97 97 97 98 98 98 99 99 99 100 100 100 101 101 101 102 102 102 103 103 103 104 104 104 105 105 105 106 106 106 107 107 107 108 108 108 109 109 109 110 110 110 111 111 111 112 112 112 113 113 113 114 114 114 115 115 115 116 116 116 117 117 117 118 118 118 119 119 119 120 120 120 121 121 121 122 122 122 123 123 123 124 124 124 125 125 125 126 126 126 127 127 127 128 128 128 129 129 129 130 130 130 131 131 131 132 132 132 133 133 133 134 134 134 135 135 135 136 136 136 137 137 137 138 138 138 139 139 139 140 140 140 141 141 141 142 142 142 143 143 143 144 144 144 145 145 145 146 146 146 147 147 147 148 148 148 149 149 149 150 150 150 151 151 151 152 152 152 153 153 153 154 154 154 155 155 155 156 156 156 157 157 157 158 158 158 159 159 159 160 160 160 161 161 161 162 162 162 163 163 163 164 164 164 165 165 165 166 166 166 167 167 167 168 168 168 169 169 169 170 170 170 171 171 171 172 172 172 173 173 173 174 174 174 175 175 175 176 176 176 177 177 177 178 178 178 179 179 179 180 180 180 181 181 181 182 182 182 183 183 183 184 184 184 185 185 185 186 186 186 187 187 187 188 188 188 189 189 189 190 190 190 191 191 191 192 192 192 193 193 193 194 194 194 195 195 195 196 196 196 197 197 197 198 198 198 199 199 199 200 200 200 201 201 201 202 202 202 203 203 203 204 204 204 205 205 205 206 206 206 207 207 207 208 208 208 209 209 209 210 210 210 211 211 211 212 212 212 213 213 213 214 214 214 215 215 215 216 216 216 217 217 217 218 218 218 219 219 219 220 220 220 221 221 221 222 222 222 223 223 223 224 224 224 225 225 225 226 226 226 227 227 227 228 228 228 229 229 229 230 230 230 231 231 231 232 232 232 233 233 233 234 234 234 235 235 235 236 236 236 237 237 237 238 238 238 239 239 239 240 240 240 241 241 241 242 242 242 243 243 243 244 244 244 245 245 245 246 246 246 247 247 247 248 248 248 249 249 249 250 250 250 251 251 251 252 252 252 253 253 253 254 254 254 255 255 255
Re: convert olny bright gray to color
thanks XnTriq for your solution,
so you also didn't find a simple UI solution in xnview
meanwhile, I found a tool myself, that can solve my intention a bit easier, but unfortunately not on my old iMac G5. I had to
switch to (sorry) windows (7). "imageJ" does it in a few steps:
1.) Image -> Color -> Split_Channels splits your (gray) image into 3 (r=g=b identical) channel-Images
2.) then for each channel-Image:
Process -> Math -> Macro... lets you manipulate the (given) pixel value "v" in a 1-line-UI, e.g.: if ((v>99) && (v<200)) v=v/2+155
(of course you will be using different formulas for each channel-Image )
3.) Image -> Color -> Merge_Channels... merges your 3 channel-Images into 1 (now colored) image.
actually, the Macros are recordable & store-able & pretty powerful, as they also can handle other variables like pixel-xyz, width, height,...
maybe, the xnview development team may think about a similar macro/formula UI, since it's pretty straight forward & pretty powerful.
cheers, wunderer
so you also didn't find a simple UI solution in xnview
meanwhile, I found a tool myself, that can solve my intention a bit easier, but unfortunately not on my old iMac G5. I had to
switch to (sorry) windows (7). "imageJ" does it in a few steps:
1.) Image -> Color -> Split_Channels splits your (gray) image into 3 (r=g=b identical) channel-Images
2.) then for each channel-Image:
Process -> Math -> Macro... lets you manipulate the (given) pixel value "v" in a 1-line-UI, e.g.: if ((v>99) && (v<200)) v=v/2+155
(of course you will be using different formulas for each channel-Image )
3.) Image -> Color -> Merge_Channels... merges your 3 channel-Images into 1 (now colored) image.
actually, the Macros are recordable & store-able & pretty powerful, as they also can handle other variables like pixel-xyz, width, height,...
maybe, the xnview development team may think about a similar macro/formula UI, since it's pretty straight forward & pretty powerful.
cheers, wunderer
Re: convert olny bright gray to color
Thanks for reporting back, wunderer.
You have Filter » User filter... (in XnView for Windows as well as XnViewMP for Mac OS), but it's very basic:
There's only one single solitary developer: Pierrewunderer wrote:maybe, the xnview development team may think about a similar macro/formula UI, since it's pretty straight forward & pretty powerful.
You have Filter » User filter... (in XnView for Windows as well as XnViewMP for Mac OS), but it's very basic:
Re: convert olny bright gray to color
okay, let me re-phrase:
I highly appreciate and admire people like pierre, and especially the free spirit, they are following and living.
being retired by now, I was considering myself to join the freeware /open source community, however, with my skills,
it didn't really work for me. so I joined a local radio station in munich instead: lora924.de (for those who understand german)
others than that, i posted my problem/solution as a development request, and of course I understand,
there may be much more important ones to resolve first. especially with this manpower situation.
cheers, wunderer.
I highly appreciate and admire people like pierre, and especially the free spirit, they are following and living.
being retired by now, I was considering myself to join the freeware /open source community, however, with my skills,
it didn't really work for me. so I joined a local radio station in munich instead: lora924.de (for those who understand german)
others than that, i posted my problem/solution as a development request, and of course I understand,
there may be much more important ones to resolve first. especially with this manpower situation.
cheers, wunderer.
Re: convert olny bright gray to color
Firstly, this can be done entirely within xnview, though the process can be tedious if you're changing a lot of colors. Take your greyscale image, then go image->convert to colors and set the # of colors to match the # of grayscale "colors". Now image->edit palette (or just ctrl+m). From here just double click the lightest whites/greys shown and set the to red or blue or whatever you're going for. The drawback is that you have to manually edit every color that you want to change.
Alternatively, from that same edit palette dialog you can export into a number of different formats. Windows palette is apparently binary & can't be editted with notepad. Most of the others are apparently plain text, but when I edit->save->load, I get a "not valid palette" error (including with the PSP format). However, the gimp format is truly plain text and can be editted->saved->loaded with no problems.
Alternatively, from that same edit palette dialog you can export into a number of different formats. Windows palette is apparently binary & can't be editted with notepad. Most of the others are apparently plain text, but when I edit->save->load, I get a "not valid palette" error (including with the PSP format). However, the gimp format is truly plain text and can be editted->saved->loaded with no problems.
Oh the feuhrer, oh the feuhrer, oh the feuhrer's nipples bonk!
Re: convert olny bright gray to color
thanks Drahken,
you mainly pointed out the solution XnTriq suggested.
of course it's very tedious interactively pixel by pixel,
but with a little perl script I am able to also re-assign rgb-ranges.
now I can even do it entirely on my good old iMac.
(both, CF & Paintshop palette, worked fine for this )
thanks a lot, wunderer.
you mainly pointed out the solution XnTriq suggested.
of course it's very tedious interactively pixel by pixel,
but with a little perl script I am able to also re-assign rgb-ranges.
now I can even do it entirely on my good old iMac.
(both, CF & Paintshop palette, worked fine for this )
thanks a lot, wunderer.