Quicklook

Generates a subsampled version of an image extract

Description

Generates a subsampled version of an extract of an image defined by ROIStart and ROISize. This extract is subsampled using the ratio OR the output image Size.

This application has several output images and supports “multi-writing”. Instead of computing and writing each image independently, the streamed image blocks are written in a synchronous way for each output. The output images will be computed strip by strip, using the available RAM to compute the strip size, and a user defined streaming mode can be specified using the streaming extended filenames (type, mode and value). Note that multi-writing can be disabled using the multi-write extended filename option: &multiwrite=false, in this case the output images will be written one by one. Note that multi-writing is not supported for MPI writers.

Parameters

Input Image -in image Mandatory
The image to read

Output Image -out image [dtype] Mandatory
The subsampled image

Channel List -cl string1 string2...
Selected channels

ROI Origin X -rox int Default value: 0
first point of ROI in x-direction

ROI Origin Y -roy int Default value: 0
first point of ROI in y-direction

ROI Size X -rsx int Default value: 0
size of ROI in x-direction

ROI Size Y -rsy int Default value: 0
size of ROI in y-direction

Sampling ratio -sr int Default value: 2
Sampling Ratio, default is 2

Size X -sx int
quicklook size in x-direction (used if no sampling ratio is given)

Size Y -sy int
quicklook size in y-direction (used if no sampling ratio is given)

Examples

From the command-line:

otbcli_Quicklook -in qb_RoadExtract.tif -out quicklookImage.tif

From Python:

import otbApplication

app = otbApplication.Registry.CreateApplication("Quicklook")

app.SetParameterString("in", "qb_RoadExtract.tif")
app.SetParameterString("out", "quicklookImage.tif")

app.ExecuteAndWriteOutput()

Limitations

This application does not provide yet the optimal way to decode coarser level of resolution from JPEG2000 images (like in Monteverdi). Trying to subsampled huge JPEG200 image with the application will lead to poor performances for now.