Peppe, would you mind posting your answer in the jira ticket [1] or do you want me to post it in your stead?
..ede [1] https://issues.apache.org/jira/browse/IMAGING-267?page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel&focusedCommentId=17200118#comment-17200118 On 22.09.2020 18:37, Giuseppe Aruta wrote: > /First off, this TIFF appears to be geophysical data. But there are no > GeoTIFF tags bundled with the image. Judging from the ModelTiepointTag, it > appears that the original image was configured using a projected coordinate > system, maybe a UTM zone. It might help me understand this better if there > were more location information attached to the image. Do you have that > information?/ > > No. This image comes from image samples used by Victor Oyala to test Sextante > and had no attached crs . I think this image is related to an UTM zone in > Spain. > > /Secondly, I note that this TIFF file is not strictly-speaking an image , but > is actually numerical data stored using the TIFF standard floating-point > raster format. My guess is that it's probably elevations. The ability to > process TIFF files containing floating point data was introduced in the most > recent release of Commons Imaging./ > > Yes, Those are elevation data > > /I've attached the image I produced (ISSUE_267.JPG). However, to create it, > I had to know before hand what the range of values was. So my application > does a few extra steps that I did not show in the example above. I was > wondering how the software you used handles this issue. Is it all automatic?/ > > Yes. In OpenJUMP reads the range either in a aux.xml sidecar file or it > computes using JAI.create("extrema") method > > /Also, a second question I had is that the PhotometricInterpretation tag > given with your image is 1, which means "0 is black". In other words, the > palette should range from the darkest shading for the lowest numerical values > to the lightest shading for the highest values. However, in looking at your > image I notice that the lowest value pixels are drawn in the lightest colors, > which seems to contradict the setting in the source TIFF file. In the image > I've attached, the lowest value pixels are draw in the darkest colors, which > is consistent with the specification in the TIFF image. Is there some > setting in the application you used that overwrites the settings from the > TIFF file?/ > > The buffered Image to display into the view of the monoband is overwritten > in order to define a range of colours used to display it (I think it is the > method stretchImageValuesForDisplay() in RasterImage class). This method > defines the range of colour (Bloack to white) and saves as > RasterImageSymbology map (sorry for bad explanation). Thus we can change the > range of colours, creating a discrete range instead of continuous one, set a > subrange/value of the pixel to a specific colour > > Il giorno mar 22 set 2020 alle ore 15:33 <edgar.sol...@web.de > <mailto:edgar.sol...@web.de>> ha scritto: > > hey Gang, > > Gary at Apache-Commons-Imaging has some questions regarding a monoband > TIF i provided. would one of you with a deeper knowledge of rasters (Peppe, > Jukka, both?) answer him please in the ticket linked below (you need an > account, so may have to register, but it's painless and fast). > > thanks.. ede > > > -------- Forwarded Message -------- > Subject: [jira] [Commented] (IMAGING-267) Colorful rendering of b/w > Monoband TIF > Date: Tue, 22 Sep 2020 00:06:00 +0000 (UTC) > From: Gary Lucas (Jira) <j...@apache.org <mailto:j...@apache.org>> > To: edgar.sol...@web.de <mailto:edgar.sol...@web.de> > > > [ > https://issues.apache.org/jira/browse/IMAGING-267?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17199709#comment-17199709 > > <https://issues.apache.org/jira/browse/IMAGING-267?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17199709#comment-17199709> > ] > > Gary Lucas commented on IMAGING-267: > ------------------------------------ > > Thank you for posting the images. They may help to answer some issues > I've wondered about for awhile. I've inspected their content and I have a > few questions for you. > > First off, this TIFF appears to be geophysical data. But there are no > GeoTIFF tags bundled with the image. Judging from the ModelTiepointTag, it > appears that the original image was configured using a projected coordinate > system, maybe a UTM zone. It might help me understand this better if there > were more location information attached to the image. Do you have that > information? > > Secondly, I note that this TIFF file is not strictly-speaking an image , > but is actually numerical data stored using the TIFF standard floating-point > raster format. My guess is that it's probably elevations. The ability to > process TIFF files containing floating point data was introduced in the most > recent release of Commons Imaging. > > One challenge of floating point images is how to map the range of values > to gray scale. In this case, the following text gives the TIFF Tags attached > to the image: > > Directory 0 Has TIFF Image Data, description: Root > 256 (0x100: ImageWidth): 601 (1 Long) > 257 (0x101: ImageLength): 410 (1 Long) > 258 (0x102: BitsPerSample): 32 (1 Short) > 259 (0x103: Compression): 1 (1 Short) > 262 (0x106: PhotometricInterpretation): 1 (Indicates "zero is black") > 277 (0x115: SamplesPerPixel): 1 (1 Short) > 278 (0x116: RowsPerStrip): 8 (1 Long) > 339 (0x153: SampleFormat): 3 (Indicates float-point format) > 33550 (0x830e: ModelPixelScaleTag): 25.0, 25.0 (2 Double) > 33922 (0x8482: ModelTiepointTag): 0.0, 0.0, 0.0, 262846.525725, > 4464275.0, 0.0 (6 Double) > 42113 (0xa481: GDALNoData): 45, 51, 50, 55, 54, 56, 46, 48 (8 Byte) > > Upon inspection, I find that the values in the image range from 514 to > 2410. Commons Imaging does have an API element called the > custom-photometric-interpreter that lets an application specify how colors > (or gray tones) are assigned to elevations. So in this case, I was able to > render the data by specifying the following lines: > > {{ HashMap<String, Object> params = new HashMap<>(); }} > {{ PhotometricInterpreterFloat pi = }} > {{ new PhotometricInterpreterFloat(514.0f, 2410.0f);}} > {{ params.put(TiffConstants.PARAM_KEY_CUSTOM_PHOTOMETRIC_INTERPRETER, > pi);}} > {{ BufferedImage bImage = Imaging.getBufferedImage(target, params);}} > {{ ImageIO.write(bImage, "JPG", output);}} > > > > I've attached the image I produced (ISSUE_267.JPG). However, to create > it, I had to know before hand what the range of values was. So my > application does a few extra steps that I did not show in the example above. > I was wondering how the software you used handles this issue. Is it all > automatic? > > Also, a second question I had is that the PhotometricInterpretation tag > given with your image is 1, which means "0 is black". In other words, the > palette should range from the darkest shading for the lowest numerical values > to the lightest shading for the highest values. However, in looking at your > image I notice that the lowest value pixels are drawn in the lightest colors, > which seems to contradict the setting in the source TIFF file. In the image > I've attached, the lowest value pixels are draw in the darkest colors, which > is consistent with the specification in the TIFF image. Is there some > setting in the application you used that overwrites the settings from the > TIFF file? > > !ISSUE_267.JPG! > > > > > Colorful rendering of b/w Monoband TIF > > -------------------------------------- > > > > Key: IMAGING-267 > > URL: https://issues.apache.org/jira/browse/IMAGING-267 > <https://issues.apache.org/jira/browse/IMAGING-267> > > Project: Commons Imaging > > Issue Type: Bug > > Reporter: edgar soldin > > Priority: Major > > Attachments: ISSUE_267.JPG, mdt25a-commons.png, > mdt25a-sextante.png, mdt25a.tif > > > > > > see attached images. > > mdt25a.tif - the original tif > > mdt25a-commons.png - as rendered/read with Commons Imaging > > mdt25a-sextante.png - as rendered /read properly with ImageIO-Core from > https://github.com/jai-imageio/jai-imageio-core > <https://github.com/jai-imageio/jai-imageio-core> > > thanks!.. ede > > > > -- > This message was sent by Atlassian Jira > (v8.3.4#803005) > > > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > <mailto:Jump-pilot-devel@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > <https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel> > > > > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
