View source for pnm mod.scale

{{DavinciWiki_Function|
Resizes the specified array using bilinear interpolation.

Located  in "pnm_mod"  module.
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Inputs:   a Val (byte or other) and the scaling parameters

Outputs:  a Val that has been resized
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[[Syntax]]: pnm_mod.scale(data &#61; VAL [,  xsize &#61; INT][, ysize &#61; INT][, xscale  &#61; FLOAT][, yscale  &#61; FLOAT])
 
 data:     any davinci array (most likely  a  byte image array)
 xsize:    size of the x direction
 ysize:    size of the y direction 
 xscale:   ratio of the x direction to resize by
 yscale:   ratio of the y direction to resize by

You may specify a SINGLE axis change.  For example, xsize OR xscale. The aspect ratio will be maintained.

You may also specify BOTH axis. For example, xscale & yscale.

SIZE values are literal (i.e., pixels) whereas SCALE values are factors.  I.e., < 1 implies SHRINK, > 1 implies GROW.
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 dv> a&#61;read("http://davinci.asu.edu/images/d/df/llama_face.jpg")
 Downloading..done.
 ..................................................
 /tmp/dv_7970/nGBCmR: bip JPEG image: 640x530x3, 8 bits
 640x530x3 array of byte, bip format [1,017,600 bytes]
 
 dv> b&#61;pnm_mod.scale(a,xsize&#61;150,ysize&#61;150)
 150x150x3 array of byte, bip format [67,500 bytes]
 dv> c&#61;pnm_mod.scale(a,xscale&#61;1.2)
 768x636x3 array of byte, bip format [1,465,344 bytes]
 
 dv> display(a)
 Writing /tmp/dv_7970/YplXVV: 640x530x3 PNG file.
 dv> display(b)
 Writing /tmp/dv_7970/MrqA07: 150x150x3 PNG file.
 dv> display(c)
 Writing /tmp/dv_7970/HVDGpx: 768x636x3 PNG file.
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[[Image:llama_face.jpg|200px]][[Image:llama_face_scale_small.jpg|150px|]][[Image:llama_face_scale_large.jpg|300px]]

Three images where the  leftmost is the original, the center is asymmetrically scaled down and the right has been up-scaled using a single scale axis
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*[[rotate]]
*[[pnm_mod.pad]]
*[[pnm_mod.cut]]
*[[image_resize]]
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1.69
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[[category:Functions]]
[[category:Modules]]
[[category:Miscellaneous]]