#918 closed defect (worksforme)
Incorrect display of Raster
| Reported by: | yjacolin | Owned by: | ersts |
|---|---|---|---|
| Priority: | minor: annoyance | Milestone: | |
| Component: | Rasters | Version: | Trunk |
| Keywords: | raster, tile, blank line | Cc: | yjacolin@… |
| Must Fix for Release: | No | Platform: | Mandriva |
| Platform Version: | Awaiting user input: | yes |
Description
When displaying several raster tiles some blanck lines appear in the map windows. These blank lines appear only when we click on the "zoom to map extent of the map" tool. If we use the "drag and drop zoom in" tool, no blank line appear.
Note, that some tile are shown with different color. Here is a screenshot : http://softlibre.free.fr/bug/qgis/0.9.2/bug_raster_line_and_color_1.png
Change History (4)
follow-up: 2 comment:1 by , 16 years ago
| Awaiting user input: | set |
|---|---|
| Owner: | changed from to |
comment:2 by , 16 years ago
Hi erts,
Q - What data type are each tile? geotiff, IMG, etc.
The format is ECW.
Q - What projection are these data in?
The projection is lambert 2 étendue (EPSG: 27572)
Q - Approximately what is the size pixel dim and file size of each tile?
File size: 320 Mo to 35 Mo par tuile, Size is 10000, 10000 px
Q - If you load only two adjacent tiles (that have a blank band between them in the screen shot you provided) do you still experience the same result?
Yes, I do, while with four tiles I have not this problem.
Q - Is the data you are using freely accessible, if so could you provide a link to that data provider or a sample of two adjacent tiles that have a blank band in between them?
Sorry, the files are not freely available :(
Regarding the tiles appear a little red/pink, there is no histogram matching between images, so it is likely there are just some slight differences in contrast enhancement because of the way the initial min max are being estimated on initial loading. If you modify the contrast by hand or even try to "load min max from band" I am certain they will match more closely.
Your are right, this option corrected the difference. Thanks.
Y.
comment:3 by , 16 years ago
| Resolution: | → worksforme |
|---|---|
| Status: | new → closed |
Looks like this is resolved. Feel free to reopen
yjacolin,
Could you provide a little more information regarding the data you are using?
Q - What data type are each tile? geotiff, IMG, etc.
Q - What projection are these data in?
Q - Approximately what is the size pixel dim and file size of each tile?
Q - If you load only two adjacent tiles (that have a blank band between them in the screen shot you provided) do you still experience the same result?
Q - Is the data you are using freely accessible, if so could you provide a link to that data provider or a sample of two adjacent tiles that have a blank band in between them?
Regarding the tiles appear a little red/pink, there is no histogram matching between images, so it is likely there are just some slight differences in contrast enhancement because of the way the initial min max are being estimated on initial loading. If you modify the contrast by hand or even try to "load min max from band" I am certain they will match more closely.