[Matplotlib-users] imshow for .png- low resultion

[Asma R. <asm...@gm...>]

Hi
I am trying to merge a heat map(matplotlib) with a tree(.png), but the .png
does not plot as needed or for that matter cannot be seen easily. Here is
my code:

####### CODE
 cmap = mpl.cm.hot
    if outlier==0:
       threshold=1
    else:
       threshold=outlier-0.01

    fig = plt.figure(figsize=(25,25))
    plt.suptitle(file_handle.replace('.csv',''),fontsize=22)
    cmap.set_over('green')
    cmap.set_under('grey')
    gs=gridspec.GridSpec(1, 2,height_ratios=[1,1,-2,2]
,width_ratios=[1,1,-2,2])
    phyl_ax=plt.subplot(gs[0],frameon=False)
    ht_ax=plt.subplot(gs[1])
    ##gs.tight_layout(fig, rect=[1,1,2,2])
    ht_ax.set_xlim(0,35)
    ht_ax.set_ylim(0,35)
    ##ht_ax.grid(color='white',linestyle='-',linewidth=1)
    fig.subplots_adjust(hspace=0)
    cb_ax,kw =mpl.colorbar.make_axes(ht_ax, shrink=0.65)


    plt.setp(phyl_ax.get_xticklabels(),visible=False)
    plt.setp(phyl_ax.get_yticklabels(),visible=False)
    plt.setp(ht_ax.get_xticklabels(),visible=True)
    plt.setp(ht_ax.get_yticklabels(),visible=True)
    plt.setp(phyl_ax.get_xticklines(),visible=False)
    plt.setp(phyl_ax.get_yticklines(),visible=False)
    plt.setp(ht_ax.get_xticklines(),visible=True)
    plt.setp(ht_ax.get_yticklines(),visible=True)


    img = ht_ax.imshow(data, cmap=cmap, interpolation='none',vmax=threshold)
    cb = mpl.colorbar.ColorbarBase(ax=cb_ax,cmap=cmap,
extend='neither',**kw)
    cb.cmap.set_over('green')
    image_file =
cbook.get_sample_data('/home/asmariyaz/Desktop/mytree.png',asfileobj=False)
    image = plt.imread(image_file)

How can I make the resolution of the .png image better OR for that matter
is there a better solution to merge these together?

I am attaching the plot I am getting with this code- (WrongTree.pdf)

Thanks
Asma