imagepane.py

from kivy.uix.scatter import Scatter
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.stencilview import StencilView
from kivy.uix.slider import Slider
from kivy.graphics.texture import Texture
from kivy.lang import Builder
from kivy.uix.widget import Widget
from kivy.properties import ObjectProperty, NumericProperty
from numpy import nanmin, nanmax

Builder.load_string('''
#:kivy 1.8.0

<ImagePane>:
    orientation: 'vertical'
    StencilView:
        size_hint: 1., 0.7
        BoxLayout:
            size: root.size
            pos: root.pos
            padding: 20
            orientation: 'horizontal'
            ScatterLayout:
                id: the_scatter
                do_rotation: False
                do_translation: self.scale != 1
                Widget:
                    id: the_image
                    canvas:
                        Rectangle:
                            size: self.size
                            pos: self.pos
                            texture: root.iregion
    GridLayout:
        size_hint: 1., 0.3
        cols: 2
        Label:
            text: 'Stretch mode:'
            size_hint_y: 
        Label:
            text: 'Stretch factor:'
        Spinner:
            id: smode
            text: 'linear'
            values: 'linear', 'logarithmic', 'gamma', 'arcsinh', 'square root', 'histogram equalization'
            on_text: root.update_slider()
        Slider:
            id: sfactor
            value_normalized: 0.5
            disabled: True
        BoxLayout:
            orientation: 'horizontal'
            Button:
                text: 'Reset Zoom'
                on_press: root.reset_zoom()
            Button:
                text: 'Submit'
                on_press: root.submit_changes()
        BoxLayout:
            orientation: 'horizontal'
            Label:
                text: 'Min'
            TextInput:
                text: '%f6'%root.tmin
                multiline: False
            Label:
                text: 'Max'
            TextInput:
                text: '%f6'%root.tmax
                multiline: False
        ''')    
    
        
class ImagePane(BoxLayout):
    data = ObjectProperty(None)
    itexture = ObjectProperty(Texture.create(size = (2048, 2048)))
    iregion = ObjectProperty(None)
    tmin = NumericProperty(0.)
    tmax = NumericProperty(0.)
    
    def load_data(self, dataobj):
        self.data = dataobj
        print self.data.threshold
        self.tmin = float(self.data.threshold[0])
        self.tmax = float(self.data.threshold[1])
        self.iregion = self.itexture.get_region(0, 0, self.data.dimensions[0], \
            self.data.dimensions[1])
        aspect = float(self.data.dimensions[0]) / float(self.data.dimensions[1])
        self.ids.the_image.size_hint = (1./aspect, 1.) if aspect > 1 else (1., aspect)
        self.update_display()
    
    def update_display(self):
        idata = ''.join(map(chr,self.data.scaled))
        self.itexture.blit_buffer(idata, colorfmt='luminance', bufferfmt='ubyte', \
            size = self.data.dimensions)
        self.itexture.ask_update(None)
    
    def update_slider(self):
        mode = self.ids.smode.text
        factor = self.ids.sfactor
        if mode in ['linear', 'histogram equalization', 'square root']:
            factor.disabled = True
        elif mode == 'gamma':
            factor.disabled = False
            factor.range = (-1, 1)
            factor.step = 0.05
            factor.value = 0
        elif mode == 'logarithmic':
            factor.disabled = False
            factor.range = (1, 10)
            factor.step = 0.25
        elif mode == 'arcsinh':
            factor.disabled = False
            factor.range = (1, 6)
            factor.step = 0.1
    
    def reset_zoom(self):
        scatr = self.ids.the_scatter
        scatr.pos = 0, 0
        scatr.scale = 1
    
    def submit_changes(self):
        factor = self.ids.sfactor.value
        if self.ids.smode.text == 'gamma':
            factor = 10.**factor
        info = {'min':self.tmin, 'max':self.tmax, \
            'mode':self.ids.smode.text, 'factor':factor}
        self.data.change_parameters(info)
        self.update_display()
            
        

if __name__ == '__main__':
    from kivy.base import runTouchApp
    from fitsimage import ScalableImage
    from numpy import array
    tmp = array([ x / 8 + 1 for x in range(1024)])
    data = tmp + tmp.reshape(-1,1)
    im = ScalableImage(data, scalemode='gamma', factor=0.3)
    wid = ImagePane()
    wid.load_data(im)
    runTouchApp(wid)